Faculty Profiles - TAKEGAMI Yasuhiko

Papers - TAKEGAMI Yasuhiko

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Computed tomography-based navigation versus accelerometer-based portable navigation in total hip arthroplasty for dysplastic hip osteoarthritis

Tanaka, S; Osawa, Y; Takegami, Y; Funahashi, H; Ido, H; Asamoto, T; Imagama, S

EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY AND TRAUMATOLOGY Vol. 35 ( 1 ) page： 83 2025.3

Fatty infiltration of periarticular muscles in patients with osteonecrosis of the femoral head

Otaka, K; Osawa, Y; Takegami, Y; Iida, H; Funahashi, H; Imagama, S

INTERNATIONAL ORTHOPAEDICS 2025.2

Language：English Publishing type：Research paper (scientific journal) Publisher：International Orthopaedics

Purpose: Muscle mass and fatty infiltration can be assessed on computed tomography (CT) images using the cross-sectional area (CSA) and computed tomography attenuation value (CTV). Femoral head collapse in osteonecrosis of the femoral head (ONFH) may affect both values. We investigated factors influencing the CSA and CTV of the periarticular muscles in patients with ONFH. Methods: Overall, 101 patients with ONFH with unilateral hip pain (stage 2, 24 patients; stage 3 A, 49 patients; and stage 3B, 28 patients) were included. The CSA and mean CTV of the bilateral gluteus maximus (Gmax), gluteus medius (Gmed), gluteus minimus (Gmin), and iliopsoas (IP) muscles were measured using CT cross-sections. Bilateral comparisons and associations with Japanese Investigation Committee (JIC) stage were analysed. Multiple regression analysis was used to evaluate factors associated with the CSA and CTV. Results: On the symptomatic side, the CSA was significantly lower for the Gmax, Gmed, and IP, whereas the CTV was significantly lower for all tested muscles (all p < 0.01). The CTV, but not the CSA, of the Gmax, Gmed, and Gmin was significantly associated with the JIC stage severity bilaterally (all p < 0.01). Multiple regression analysis showed significant associations of the CTV with age, sex, and JIC stage (all p < 0.01). Conclusion: Symptomatic ONFH leads to decreased muscle mass and increased fatty infiltration. Femoral head collapse progression is associated with a decrease in the CTV. Periarticular muscle assessment, including on the contralateral side, is important in patients with ONFH, particularly in older women.

DOI： 10.1007/s00264-025-06457-9

特集股関節温存手術-寛骨臼側股関節周囲骨切り術- 偏心性寛骨臼回転骨切り術のピットフォール

大澤郁介, 竹上靖彦, 船橋洋人, 今釜史郎

関節外科　基礎と臨床 Vol. 44 ( 2 ) page： 131 - 138 2025.2

Discrepancy between radiography and magnetic resonance imaging in Japanese Investigation Committee classification type C osteonecrosis of the femoral head.

Otaka K, Osawa Y, Takegami Y, Funahashi H, Imagama S

International orthopaedics Vol. 49 ( 2 ) page： 391 - 397 2025.2

Discrepancy between radiography and magnetic resonance imaging in Japanese Investigation Committee classification type C osteonecrosis of the femoral head

Otaka, K; Osawa, Y; Takegami, Y; Funahashi, H; Imagama, S

INTERNATIONAL ORTHOPAEDICS Vol. 49 ( 2 ) page： 391 - 397 2025.2

Discrepancy between radiography and magnetic resonance imaging in Japanese Investigation Committee classification type C osteonecrosis of the femoral head

Otaka, K; Osawa, Y; Takegami, Y; Funahashi, H; Imagama, S

INTERNATIONAL ORTHOPAEDICS Vol. 49 ( 2 ) page： 391 - 397 2025.2

Discrepancy between radiography and magnetic resonance imaging in Japanese Investigation Committee classification type C osteonecrosis of the femoral head Open Access

Otaka K., Osawa Y., Takegami Y., Funahashi H., Imagama S.

International Orthopaedics Vol. 49 ( 2 ) page： 391 - 397 2025.2

Language：English Publishing type：Research paper (scientific journal) Publisher：International Orthopaedics

Purpose: The Japanese Investigation Committee (JIC) classification for osteonecrosis of the femoral head (ONFH) is based on the necrotic area relative to the weight-bearing surface on anteroposterior (AP) radiographs or central coronal MRI. Discrepancies exist between these methods, potentially related to the AP necrosis area. This study evaluated these discrepancies and the extent of AP necrotic lesions. Methods: We retrospectively reviewed 139 patients (188 hips) with nontraumatic ONFH, JIC type C1 or C2 on radiography, and collapse < 3 mm. Cases with and without discrepancies between radiography and MRI were designated as discrepancy and consistent groups, respectively. We assessed the proportion of patients in the discrepancy group and survival rates in both groups, with femoral head collapse > 3 mm as the endpoint. The cutoff value for AP necrotic regions on lateral radiographs identifying discrepancies was calculated using ROC curve analysis. Results: The discrepancy group comprised 28 hips (14.9%) vs. 160 hips in the consistent group. Five-year survival rates were 73.3% vs. 31.9% (P < 0.01), and AP necrotic region extent was 61.2 vs. 73.8 mm (P < 0.001) in discrepancy vs. consistent groups. The cutoff value for necrotic region extent revealing discrepancies was 66.9% (AUC 0.833, sensitivity 83.8%, specificity 82.4%). Conclusion: Patients with AP necrotic regions < 66.9% were more likely to show discrepancies between radiography and MRI in type classification. This study can help improve accuracy in assessing ONFH severity and prognosis.

DOI： 10.1007/s00264-024-06396-x

A Case of Successful Perioperative Rehabilitation in Two-Stage Revision Total Hip Arthroplasty for an Intraoperative Acetabular Fracture: Insights Into Interim-Period Rehabilitation Strategies.

Nojiri S, Osawa Y, Tanaka S, Takegami Y

Cureus Vol. 17 ( 2 ) page： e78619 2025.2

連載最新原著レビュー大腿骨頭壊死における圧潰停止は骨頭前後の壊死範囲と関連する

大澤郁介, 関泰輔, 竹上靖彦, 今釜史郎

整形外科 Vol. 76 ( 1 ) page： 89 - 93 2025.1

地域在住高齢者の転倒と転倒予防〜ロコモティブシンドロームおよび脊椎グローバルアライメントの観点から〜 Reviewed

世木直喜, 中島宏彰, 伊藤定之, 大内田隼, 飯田浩貴, 竹上靖彦, 田中智史, 両角正義, 村本明生, 小林和克, 石塚真哉, 関泰輔, 長谷川幸治, 今釜史郎

日本転倒予防学会誌 Vol. 10 ( 1 ) page： 19 - 25 2024.3

Early Recovery of Physical Function After Total Hip Arthroplasty in a Patient With Osteopetrosis: A Case Report Reviewed

Nojiri, S; Kayamoto, A; Terai, C; Osawa, Y; Takegami, Y

CUREUS JOURNAL OF MEDICAL SCIENCE Vol. 16 ( 1 ) page： e52293 2024.1

Factors affecting return to sports after eccentric rotational acetabular osteotomy Open Access

Osawa Y., Seki T., Takegami Y., Makida K., Ochiai S., Hasegawa Y., Imagama S.

Revue de Chirurgie Orthopedique et Traumatologique Vol. 109 ( 4 ) 2023.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Revue de Chirurgie Orthopedique et Traumatologique

Background: Although eccentric acetabular rotation osteotomy (ERAO) is an effective treatment for developmental dysplasia of the hip (DDH), there is little information about return to sports after ERAO. This study aimed to investigate 1) the patient factors that influence the return to sports after ERAO, 2) whether postoperative sports participation will affect future osteoarthritis progression. Hypothesis: Some factors affect the return to sports after ERAO. Patients and methods: Of 503 patients who underwent ERAO from 1990 to 2010, 124 who had been continuously participating in sports preoperatively (average 13.2 years after surgery) were included. Patient demographics of sex, age, body mass index, unilateral to bilateral case ratio, history of treatment for childhood DDH, preoperative Kellgren-Lawrence (KL) grade, center edge angle, joint congruency, Harris hip score, complications and the survival rate were compared between the S group (patients who participated in the same sports preoperatively) and N group (patients who could not participate in sports postoperatively). Results: Seventy-two (58%) and 52 patients (42%) in the S and N groups, respectively, had an overall return to sports rate of 64% (79 patients). The most common sports that patients participated in were swimming (30 patients [24%]), jogging (12 [10%]), and golf (10 [8%]) preoperatively, and swimming (14 patients [11%]), golf (8 [6%]), and jogging (8 [6%]) postoperatively. There were no significant differences between both groups in terms of sex, age, body mass index, unilateral to bilateral case ratio, history of treatment for childhood DDH, preoperative KL grade, and joint congruency. There was a significant difference in patient factors between the S (11 joints [14%]) and N (20 joints [38%]) groups only when the preoperative center edge angle was < 0°. There was no significant difference in the preoperative Harris hip score and the final survey between the S (73.2 ± 4.6 and 93.4 ± 7.2) and N (72.5 ± 4.8 and 92.1 ± 7.4) groups. Complications showed no significant differences between the five patients (7%) in the S group and six patients (13%) in the N group. The KL grade progressed in 10 cases (grade II to III in 2 cases and grade III to IV in 8) in the S group and 8 cases (grade II to III in 1 case and grade III to IV in 7 cases) in the N group. The 10-year and 20-year joint survival rates with THA conversion as the endpoint were 98.1% (95% CI: 87.4%–99.7%) and 83.7% (95% CI: 62.6%–93.4%) in the S group and 100% (95% CI: 70.7%–99.3%) and 95.2% (95% CI: 12.6%–92.6%) in the N group, respectively. In the evaluation of factors affecting sports return by logistic regression analysis, only one significant factor (odds ratio 3.42, 95% confidence interval: 1.58–7.42, p < 0.01) was the preoperative center edge angle < 0°. Discussion: The chief factor affecting the return to sports after surgery was a preoperative center edge angle < 0°; moreover, the continuation of sports did not affect the subsequent progression of osteoarthritis or THA conversion. Level of evidence: Level III, cohort study.

DOI： 10.1016/j.rcot.2022.10.006

Re: Shibata et al. Comparison of surgical treatments for distal ulna fracture when combined with anterior locking plate fixation of the distal radius in the over 70 age group. J Hand Surg Eur. Epub ahead of print 28 January 2023. DOI: 10.1177/17531934221150495 Invited Reviewed

Shibata, R; Tokutake, K; Takegami, Y; Natsume, T; Matsubara, Y; Imagama, S

JOURNAL OF HAND SURGERY-EUROPEAN VOLUME 2023.4

人工股関節全置換術術後のPelvic obliquityは術前の腰椎側屈可動性と関連している Reviewed

小澤悠人, 大澤郁介, 竹上靖彦, 船橋洋人

日本関節病学会誌 Vol. 42 ( 1 ) page： 12 - 21 2023

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：日本関節病学会

<p><b>目的</b>：側方骨盤傾斜は変形性膝関節症や変形性腰椎症などの隣接椎間障害や自覚的な脚長差を生じることからQOLを障害する因子の一つとして知られている。変形性股関節症では脚長差や可動域制限により側方骨盤傾斜を呈することが少なくなく，ときとして人工股関節置換術（以下THA）後でも側方骨盤傾斜の改善が得られない症例が存在する。本研究の目的はTHA後の側方骨盤傾斜を認めない症例と残存する症例を比較し，術後側方骨盤傾斜に影響を与える因子について調査することである。</p><p><b>症例および方法</b>：単一施設後ろ向きコホート研究にて，2018年6月から2020年7月までに片側THAを行った91股を対象とした。これらの症例をTHA後の側方骨盤傾斜が2°以内であった48例（以下F群）と2°以上であった43例（以下O群）に分けた。調査項目は年齢，性別，身長，体重，Body Mass Index，術前後のHarris hip score（以下HHS），術前後の股関節可動域，術前後の自覚的脚長差の有無，術前後の側方骨盤傾斜，脚長差，オフセット，術前腰椎側屈可動性について両群間で比較検討を行い，多変量解析を用いて術後の側方骨盤傾斜に影響する因子を評価した。</p><p><b>結果</b>：年齢，性別，身長，体重，BMIは両群で有意差を認めなかった。術前のHHSは両群で有意差を認めなかったが，術後1年でのHHSはF群90.8±7.6に対してO群86.4±11.0で有意にO群が不良であった。術前自覚的脚長差には両群で有意差を認めなかったが術後の自覚的脚長差認識率はF群で20.8%，O群で51.1%と有意にO群で自覚的脚長差を有する症例が多かった。術前後の画像的な脚長差は両群で有意差を認めなかった。術前の腰椎側屈可動性はF群で8.7±4.3°，O群で6.9±4.9°で有意にO群が不良であった。多変量解析の結果では術前側方骨盤傾斜と術前の腰椎側屈可動性が術後の側方骨盤傾斜≧2°の有意なリスク因子であった。</p><p><b>結論</b>：術前の側方骨盤傾斜が大きい症例や腰椎可動性が不良な症例ではTHA後の側方骨盤傾斜が残存するリスクが高く，慎重な術前計画が必要である。</p>

DOI： 10.11551/jsjd.42.12

荷重部の後方壊死範囲が大腿骨頭壊死の圧潰停止に影響する Reviewed

大澤郁介, 関泰輔, 竹上靖彦, 加藤大策, 竹本元大

日本関節病学会誌 Vol. 41 ( 4 ) page： 275 - 279 2022

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：日本関節病学会

<p><b>目的：</b>圧潰をきたした大腿骨頭壊死が自然経過において圧潰停止し，長期的に手術治療を回避できることは少なくない。我々は骨頭後方の壊死領域の範囲が大腿骨頭壊死の圧潰停止に関与すると仮説し，後方壊死領域と圧潰停止の関係性について調査した。</p><p><b>対象および方法：</b>2010年から2016年までに当院に初回受診した片側症状かつ圧潰が3mm以内（Stage 3A）の大腿骨頭壊死77例を対象とした。性別は男性37例，女性40例で平均年齢は45.1歳，平均観察期間は48.7か月，Type分類（B/C1/C2）は3/35/39であった。調査項目は圧潰停止の有無，骨頭後方壊死領域とした。圧潰停止は初診から2年時点で3mm以内の圧潰にとどまった場合に圧潰停止と定義した。骨頭後方壊死領域はMRI横断面で骨頭後方1/3レベルの冠状断T1 MRIにおける荷重面おける壊死領域の割合を評価した。ROC曲線を用いて圧潰停止が得られる後方壊死領域のcut off値を割り出し，cut off値より圧潰進行（>3mm）および人工股関節全置換術をendpointとした生存率を評価した。</p><p><b>結果：</b>圧潰停止は31例（40%）に認めた。後方壊死域は圧潰停止例43.1±31.8%に対して圧潰進行例95.6±19.1%で有意差を認めた（<i>P</i><0.01）。ROC曲線のAUCは0.946でcut off値は後方壊死領域68%（感度96%，特異度92%）であった。圧潰進行および人工股関節全置換術をendpointとした4年生存率は後方壊死領域>68%では6.9%および33%に対し，後方壊死領域<68%では96%および93%でいずれも有意差を認めた（<i>P</i><0.01および<i>P</i><0.01）。</p><p><b>結論：</b>一旦圧潰をきたした大腿骨頭壊死においても後方壊死領域が2/3以下の症例は高い確率で自然経過による圧潰停止が期待でき，保存的治療を行うか判断する際の有効な指標となる。</p>

DOI： 10.11551/jsjd.41.275

Peroneural neuropathy after total hip arthroplasty with combined neural block: a case report Reviewed

KINUKAWA Tomoaki Alex, TAMURA Takahiro, TAKEGAMI Yasuhiko, SEKI Taisuke, NISHIWAKI Kimitoshi

Journal of Japan Society of Pain Clinicians Vol. 28 ( 9 ) page： 194 - 198 2021.9

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Pain Clinicians

<p>A 46-year-old woman, 157 cm 58 kg, underwent left total hip arthroplasty after lumbar plexus block and sciatic nerve block via the parasacral approach. Postoperative X-ray revealed 20-mm leg extension. After surgery, both legs had movement disorder and sensory disturbance, which improved within a few hours. Lumbar plexus block was considered to be an epidural block. Thereafter, sensory and motor disorders slightly improved, but recovery of dorsiflexion movement of the left ankle joint was delayed and mild peroneal neuropathy at the level of the peroneal head was diagnosed by electromyography 28 days after surgery. Thirty-two days after surgery, the patient was discharged with stable walking using a cane. The neurological symptoms were suspected to be caused by physical factors, such as hyperextension of the peroneal nerve, because the neuropathy was at the level of the peroneum. We also cannot exclude the possibility that this nerve block affected paralysis.</p>

DOI： 10.11321/jjspc.21-0029

論説多施設共同研究による脛骨骨幹部骨折に対する髄内釘固定術の成績 Reviewed

等々力一徳, 竹上靖彦, 川﨑成美, 上見亮太, 山田梨沙, 三島健一, 今釜史郎

整形外科 Vol. 72 ( 4 ) page： 301 - 305 2021.4

CIRCULATING MIR-34 IS ASSOCIATED WITH THE DEVELOPMENT OF KNEE OSTEOARTHRITIS IN COMMUNITY-DWELLING OLDER MEN Reviewed International journal

Takegami, Y; Seki, T; Ishizuka, S; Suzuki, K; Fujii, R; Hasegawa, Y; Imagama, S

OSTEOARTHRITIS AND CARTILAGE Vol. 29 page： S156 - S156 2021.4

Long-term outcomes of curved intertrochanteric varus osteotomy combined with bone impaction grafting for non-traumatic osteonecrosis of the femoral head. Reviewed

Osawa Y, Seki T, Okura T, Takegami Y, Ishiguro N, Hasegawa Y

The bone & joint journal Vol. 103-B ( 4 ) page： 665 - 671 2021.4

Long-term outcomes of curved intertrochanteric varus osteotomy combined with bone impaction grafting for non-traumatic osteonecrosis of the femoral head Reviewed

Osawa Y., Seki T., Okura T., Takegami Y., Ishiguro N., Hasegawa Y.

BONE & JOINT JOURNAL Vol. 103B ( 4 ) page： 665 - 671 2021.4

The predictor of the neuropraxia in children undergoing surgery for humeralsupracondylar fracture in children —multicenter analysis— Reviewed

WATANABE Taku

The Central Japan Journal of Orthopaedic Surgery & Traumatology Vol. 64 ( 1 ) page： 11 - 13 2021.1

偏心性寛骨臼回転骨切り術後のスポーツ復帰に影響する因子 Reviewed

大澤郁介, 関泰輔, 竹上靖彦, 牧田和也, 落合聡史

日本関節病学会誌 Vol. 40 ( 2 ) page： 110 - 115 2021

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：日本関節病学会

<p><b>目的 : </b>偏心性寛骨臼回転骨切り術 (以下ERAO) 後のスポーツ復帰率と復帰に影響を与える因子を調査した。</p><p><b>対象及び方法 : </b>1990年から2010年にERAO施行した503例の中, 術前から継続的にスポーツ参加していた124例 (術後平均13.2年) を対象とした。ERAO後に術前と同等のスポーツに参加したと答えたS群と術後参加できていないと答えたN群で評価した。調査項目は性別 (男性or女性), 年齢 (<30歳or 30歳≧), body mass index (BMI) (<25kg/m<sup>2</sup> or≧25kg/m<sup>2</sup>), 片側or両側手術例, 術前のKellgren and Lawrence (以下KL) 分類, 関節適合性 (excellent & good or fair & poor), 小児期発育性股関節形成不全の治療歴の有無, 術前のcenter edge (以下CE) 角 (≧0度or 0度>), 術後のCE角 (≧25度or 25度>), スポーツ種目, スポーツ強度, 日本整形外科学会股関節機能判定基準 (以下JOAスコア) (術前, 術後2年, 最終調査時), 術後合併症, KL分類のgrade進行をエンドポイントとした生存率を2群で比較した。<i>P</i><0.05の変数をlogistic regression analysisにより復帰阻害因子を同定した。</p><p><b>結果 : </b>S群72例 (58%), N群は52例 (42%) で全体のスポーツ復帰率は64%であった。術後に多く参加していたスポーツは水泳14例 (11%), ゴルフ8例 (6%), ジョギング8例 (6%) であった。患者因子は術前CE角0度未満のみ両群で有意差を認めた。術前, 術後2年, 最終調査時のJOAスコア及び合併症は両群で有意差を認めなかった。KL分類のGrade進行をendpointとした10年及び20年の関節生存率はS群が98.3%, 75.6%に対してN群は96.8%, 67.1%で有意差は認めなかった。Logistic regression analysisによるスポーツ復帰に影響する因子の評価では術前CE角0度未満のみ有意な因子 (オッズ比3.42, 95%IC 1.58〜7.42, <i>P</i><0.01) として抽出された。</p><p><b>結論 : </b>ERAO後のスポーツ復帰率は69%でスポーツ継続はその後の股関節症の進行には影響しなかった。術後のスポーツ復帰に影響を与える因子は術前CE角が0度未満であった。</p>

DOI： 10.11551/jsjd.40.110

転子間外反骨切りを併用した偏心性寛骨臼回転骨切り術の長期成績 Reviewed

大澤郁介, 関泰輔, 竹上靖彦, 草野大樹

日本関節病学会誌 Vol. 39 ( 4 ) page： 379 - 385 2020

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：日本関節病学会

<p><b>目的 : </b>我々は骨頭変形や関節症進行により関節適合性が不良な寛骨臼形成不全例に対して転子間外反骨切り (ITVO) を併用した偏心性寛骨臼回転骨切り術 (ERAO) を施行してきた。今回, 50歳未満の寛骨臼形成不全症に対してITVOを併用したERAOの長期成績をERAO術単独例と比較検討を行った。</p><p><b>対象および方法 : </b>1989年から2009年に寛骨臼形成不全症に対してITVO併用ERAOを施行した35例36関節 (前股関節症2例, 初期股関節症2例, 進行期股関節症28関節, 末期股関節症4関節) を対象とした。Control群は性別, 年齢, 術前病期をマッチングしたERAO単独施行した65例66関節 (ERAO群) とした。性別は全例女性で, 手術時平均年齢はERAO/ITVO群で41.1/41.9歳, 平均経過観察期間は16.5/16.2年であった。検討項目は術前および最終調査時の日本整形外科学会股関節機能判定基準 (JOA hip score), 合併症, 人工股関節全置換術 (THA) への移行およびJOA hip score<80をend pointとした生存率とした。</p><p><b>結果 : </b>術前JOA hip scoreは両群で有意差を認めなかったが最終経過観察時はITVO/ERAO群で78.9±12.3/87.4±9.7で有意にITVO群が不良であった (<i>P</i><0.01)。合併症はITVO群4例, ERAO群3例で有意差を認めなかった。THAをend pointとしたITVO/ERAO群の生存率は10年91.9/91.4%, 20年60.3/69.2%で有意差を認めなかった。JOA hip score<80をend pointとした生存率は10年56.9/82.8%, 20年42.9/72.7%で有意にITVO群が不良であった (<i>P</i><0.01)。</p><p><b>結論 : </b>股関節機能においてITVOを併用したERAOの長期成績は不良であり, 本術式の適応は若年の前, 初期股関節症に限定するべきである。</p>

DOI： 10.11551/jsjd.39.379

論説寛骨臼骨切り術の術前予後予測スコアリングシステムにおける妥当性 Reviewed

天野貴文, 関泰輔, 竹上靖彦, 室谷健太, 長谷川幸治

整形外科 Vol. 70 ( 13 ) page： 1333 - 1338 2019.12

What factors predict ceramic liner malseating after ceramic-on-ceramic total hip arthroplasty?

Higuchi Y., Seki T., Takegami Y., Osawa Y., Kusano T., Ishiguro N.

Revue de Chirurgie Orthopedique et Traumatologique Vol. 105 ( 3 ) 2019.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Revue de Chirurgie Orthopedique et Traumatologique

Background: There is a lack of evidence about the risk factors associated with the malseating of the acetabular liner after ceramic-on-ceramic (CoC) total hip arthroplasty (THA). Therefore, we performed a complementary retrospective case-control study to determine the factors predicting the malseating of the acetabular liner after CoC THA and to evaluate the relationship between malseating and (1) osteoarthritis, (2) particularly in terms of the new radiographic parameter “bone sclerotic length” of the acetabular bone. Hypothesis: Osteoarthritis, particularly bone sclerotic length, was an independent risk factor for malseating of ceramic liners. Patients and methods: In total, 219 CoC THAs (174 women and 45 men) were evaluated to determine the risk factors influencing the malseating of the acetabular ceramic liner. An average patient age at the time of surgery was 55.9 ± 9.5 years (range, 23 to 75 years). Data on patient background and preoperative radiographs, such as Tönnis grades; Crowe classification; and indices of acetabular osteoarthritis change; including bone cyst, osteophyte and bone sclerosis, were assessed. The sclerotic length in patients with osteoarthritis was measured as the length between the bilateral edges of sclerosis lesions. The bone sclerotic length was measured as the slant distance between the bilateral edges of the sclerosis lesion of the acetabulum on the anteroposterior view. Results: Preoperative less flexion (hazard ratio [HR]: 0.98; 95% CI: 0.97–0.99), osteoarthritis (HR: 3.15; 95% CI: 1.02–9.70) and the bone sclerotic length (HR: 1.83; 95% CI: 1.35–2.48) were independent risk factors determining the malseating of ceramic liners. Receiver operating characteristic curve analysis showed that a bone sclerotic length of 24.6 mm was defined as the cut-off point for the malseating of the ceramic liner. Discussion: Age, preoperative less flextion, osteoarthritis, and the bone sclerotic were independent risk factors determining malseating of ceramic liners. The acetabular shell can also deform upon insertion of the cup with sclerotic bone of the acetabulum and prevent correct seating of liners. Therefore, these factors must be taken into consideration when seating the ceramic liner. Level of evidence: Case control study III, case control retrospective design.

DOI： 10.1016/j.rcot.2019.02.018

Same survival but higher rate of osteolysis for metal-on-metal, ultamet versus ceramic-on-ceramic in patients undergoing primary total hip arthroplasty after 8 years of follow-up

Higuchi Y.

Revue de Chirurgie Orthopedique et Traumatologique Vol. 104 ( 8 ) 2018.12

Comparison of cementless total hip arthroplasty survivorship between metal-on-highly cross-linked polyethylene and ceramic on ceramic bearings: A case control study with a 5-9-year follow-up. Reviewed

Higuchi Y, Seki T, Hasegawa Y, Morita D, Komatsu D, Takegami Y, Ishiguro N

Orthopaedics & traumatology, surgery & research : OTSR Vol. 104 ( 5 ) page： 663 - 669 2018.9

Wnt/Beta-catenin Signaling as one of the Therapeutic Targets in Osteoarthritis Invited Reviewed

竹上靖彦

Nov Tech Arthritis Bone Res Vol. 2 page： 1 - 3 2018

Comparative Outcomes of Anterior and Posterior Plating for Distal-Third Humerus Shaft Fractures. Reviewed International journal

Yuya Shimamoto, Katsuhiro Tokutake, Yasuhiko Takegami, Yuta Asami, Ken Sato, Hiroki Ueno, Takahiko Nakano, Sei Fujii, Nobuyuki Okui, Shiro Imagama

The Journal of hand surgery Vol. 50 ( 3 ) page： 375.e1 - 375.e8 2025.3

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: When treating distal-third humerus shaft fractures (HSFs) surgically, the optimal approach for plating is controversial. We conducted a retrospective multicenter study to investigate and compare the clinical outcomes of anterior and posterior plating in distal-third HSFs and the incidence of complications including iatrogenic radial nerve palsy. METHODS: We identified 116 patients from our multicenter trauma database who were diagnosed as having distal-third HSFs and who underwent surgical treatment, including intramedullary nailing between 2011 and 2020. We analyzed 50 cases treated in one of two ways: open reduction internal fixation with anterior plating (group A: 20 cases) and open reduction internal fixation with posterior plating (group P: 30 cases). RESULTS: The findings were similar in terms of operation time, estimated bleeding, and clinical and radiographic outcomes between the groups. Postoperative radial nerve palsy occurred only in group P (4 cases) and never in group A. CONCLUSIONS: The results of this study suggest that the anterior approach is a safe and effective method for treating distal-third HSFs with satisfactory outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

DOI： 10.1016/j.jhsa.2023.07.014

PDZRN3 regulates adipogenesis of mesenchymal progenitors in muscle

Hiroki Iida, Minako Kawai-Takaishi, Yoshihiro Miyagawa, Yasuhiko Takegami, Akiyoshi Uezumi, Takeshi Honda, Shiro Imagama, Tohru Hosoyama

Regenerative Therapy Vol. 28 page： 473 - 480 2025.3

Impact of diffuse idiopathic skeletal hyperostosis on quality of life and locomotive syndrome in community-dwelling older adults: the Yakumo study. International journal Open Access

Kazuma Ohshima, Hiroaki Nakashima, Naoki Segi, Sadayuki Ito, Jun Ouchida, Yasuhiko Takegami, Shinya Ishizuka, Ippei Yamauchi, Yukiharu Hasegawa, Kenta Murotani, Shiro Imagama

Scientific reports Vol. 15 ( 1 ) page： 3582 - 3582 2025.1

Language：English Publishing type：Research paper (scientific journal)

Diffuse idiopathic skeletal hyperostosis (DISH) is a common disease in older adults that causes extensive spinal ankylosis. However, its impact on quality of life (QOL) and locomotive syndrome (LS) remains unknown. Thus, we aimed to evaluate the DISH effect on QOL and LS in community-dwelling middle-aged and older adults. Data of community volunteers who attended a health checkup in 2018-2019 were assessed. A total of 455 subjects were included. Whole spine lateral radiographs were obtained to detect DISH according to the Resnik criteria. QOL was evaluated using SF-36 and EQ5D HUSV. LS was evaluated using the stand-up and two-step tests and GLFS-25. Multivariate regression analysis was performed, adjusting for sex, age, body mass index, and knee osteoarthritis. Additionally, a sex-stratified analysis was performed. DISH was detected in 83 (18.2%) participants. Multivariate analysis demonstrated that DISH was significantly associated with low EQ5D HSUV. Multivariate analysis in men demonstrated that DISH was associated with low PCS, low EQ5D HSUV, high LS stage. Multivariate analysis in women demonstrated that DISH was not associated with any QOL or LS. DISH may be associated with a poor QOL. Additionally, DISH is more common and produces a greater clinical impact in men than in women.

DOI： 10.1038/s41598-025-87878-9

Risk factors for intraoperative femoral fractures in cementless bipolar hip arthroplasty for femoral neck fracture in multicenter: The TRON group study. Reviewed

Hiroaki Ido, Yasuhiko Takegami, Yusuke Osawa, Masanori Okamoto, Hiroki Iida, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 30 ( 1 ) page： 101 - 106 2025.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Intraoperative femoral fractures are more common in cementless bipolar hip arthroplasty (BHA) for displaced femoral neck fractures than they are in cemented BHA and remain one of the major concerns. This study aimed to investigate the risk factors for intraoperative femoral fractures in cementless BHA. METHODS: The study included 1,392 patients who underwent cementless BHA for displaced femoral neck fractures from January 2015 to December 2019 in 14 hospitals of the Trauma Research Group. They were divided into two groups according to the presence or absence of intraoperative femoral fractures, and factors associated with intraoperative fractures were statistically examined. RESULTS: Forty (2.9 %) intraoperative and 28 (2.0 %) postoperative, totally 68 (4.9 %) femoral fractures occurred. The mean age of the patients, presence of opposite-side proximal femoral fracture, approach, and cementless stem design were significantly different between the two groups (P < 0.05). The logistic regression analysis model showed that a fully HA-coated stem (odds ratio, 4.12; 95 % confidence interval, 1.43-11.9) was an independent factor associated with intraoperative femoral fractures. CONCLUSION: This study investigated the risk factors associated with intraoperative fractures and showed that fully HA-coated stems were an independent factor associated with intraoperative femoral fractures. Surgeons should be cautious in the early stages of introducing fully HA-coated stems.

DOI： 10.1016/j.jos.2024.01.005

Acetabular osteophyte formation in dysplastic hip osteoarthritis. Reviewed International journal Open Access

Hiroto Funahashi, Yusuke Osawa, Yasuhiko Takegami, Yuto Ozawa, Hiroaki Ido, Takamune Asamoto, Shiro Imagama

BMC musculoskeletal disorders Vol. 25 ( 1 ) page： 1072 - 1072 2024.12

Language：English Publishing type：Research paper (scientific journal)

The growth of periacetabular osteophytes with developmental dysplasia of the hip (DDH) remains unclear. This study aimed to perform a three-dimensional assessment of periacetabular osteophytes and the effects of superiorization (SP) and lateralization (LT) of the femoral head on osteophyte formation. Female (n = 105) with unilateral hip osteoarthritis due to DDH who underwent total hip arthroplasty between 2016 and 2022 were included. The SP and LT of the femoral head were assessed using anteroposterior radiographs. We measured the periacetabular osteophyte using computed tomography. The correlation coefficient between SP or LT and the length of each osteophyte were investigated. Furthermore, multiple regression analyses with SP and LT as explanatory variables and each osteophyte as an objective variable were performed to evaluate the effect of SP and LT on osteophyte formation. The longest osteophyte was the anterior osteophyte (20.48 mm ± 11.8 mm). Acetabular osteophytes correlated with LT as follows: anterior (r = 0.55), posterosuperior (r = 0.51), and inferior (r = 0.48). Multiple regression analysis showed that all acetabular osteophytes were influenced by LT (p < 0.05 for all factors). Hip surgeons may need to be aware that cases with marked lateralization of the femoral head require treatment of the periacetabular osteophytes.

DOI： 10.1186/s12891-024-08211-5

Discrepancy between radiography and magnetic resonance imaging in Japanese Investigation Committee classification type C osteonecrosis of the femoral head. Reviewed International journal

Keiji Otaka, Yusuke Osawa, Yasuhiko Takegami, Hiroto Funahashi, Shiro Imagama

International orthopaedics 2024.12

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The Japanese Investigation Committee (JIC) classification for osteonecrosis of the femoral head (ONFH) is based on the necrotic area relative to the weight-bearing surface on anteroposterior (AP) radiographs or central coronal MRI. Discrepancies exist between these methods, potentially related to the AP necrosis area. This study evaluated these discrepancies and the extent of AP necrotic lesions. METHODS: We retrospectively reviewed 139 patients (188 hips) with nontraumatic ONFH, JIC type C1 or C2 on radiography, and collapse < 3 mm. Cases with and without discrepancies between radiography and MRI were designated as discrepancy and consistent groups, respectively. We assessed the proportion of patients in the discrepancy group and survival rates in both groups, with femoral head collapse > 3 mm as the endpoint. The cutoff value for AP necrotic regions on lateral radiographs identifying discrepancies was calculated using ROC curve analysis. RESULTS: The discrepancy group comprised 28 hips (14.9%) vs. 160 hips in the consistent group. Five-year survival rates were 73.3% vs. 31.9% (P < 0.01), and AP necrotic region extent was 61.2 vs. 73.8 mm (P < 0.001) in discrepancy vs. consistent groups. The cutoff value for necrotic region extent revealing discrepancies was 66.9% (AUC 0.833, sensitivity 83.8%, specificity 82.4%). CONCLUSION: Patients with AP necrotic regions < 66.9% were more likely to show discrepancies between radiography and MRI in type classification. This study can help improve accuracy in assessing ONFH severity and prognosis.

DOI： 10.1007/s00264-024-06396-x

Changes of hip fracture in older patients before and after the COVID-19 pandemic: a retrospective multicentre study in Japan. Reviewed International journal Open Access

Shinya Tanaka, Yusuke Osawa, Yasuhiko Takegami, Nobuyuki Okui, Ken-Ichi Yamauchi, Yoshiki Aoki, Shiro Imagama

BMC musculoskeletal disorders Vol. 25 ( 1 ) page： 1006 - 1006 2024.12

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The COVID-19 pandemic had a significant impact on healthcare systems and the general population. However, it remains unclear to what extent these major societal changes have had an impact on the management of hip fractures in older people in Japan. Therefore, we investigated the effect of the COVID-19 pandemic on the number of patients with hip fractures, their characteristics, and their perioperative management as a retrospective multicentre study. METHODS: We included 1894 patients aged ≥ 65 years who underwent surgery for hip fracture at three hospitals between January 2019-December 2021. Patients were classified according to the time of injury; patients treated between January-December 2019, January-December 2020, and January-December 2021 were divided into the pre-COVID-19 group, early COVID-19 group, and late COVID-19 group, respectively. We compared age, sex, body mass index, preadmission residence, surgical procedure, length of hospital stay, waiting time for surgery, in-hospital complications, and in-hospital death. RESULTS: Our findings suggested that the early COVID-19 and late COVID-19 groups showed a 6.8% and 7.5% reduction in the number of HF patients, respectively, compared to the pre-COVID-19 group. Waiting days for surgery, length of hospital stay, and in-hospital mortality or complication rates did not significantly change before and after the pandemic. However, infection was increased in the early COVID-19 group regarding the subgroup of complications. CONCLUSIONS: The COVID-19 pandemic altered the characteristics of hip fractures in older individuals.

DOI： 10.1186/s12891-024-08050-4

The Wait Time for Surgery Following Injury Affects Functional Outcomes and Complications After an Ankle Fracture: A Propensity Score-Matched Multicenter Study, the TRON Study. Reviewed International journal

Takayuki Sugino, Yasuhiko Takegami, Kosuke Bando, Toshifumi Sato, Tomoki Fujita, Yoshiharu Oka, Shiro Imagama

Foot & ankle specialist Vol. 17 ( 6 ) page： 592 - 597 2024.12

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The present study aimed to evaluate the hypothesis that a 1-week extension of the waiting period to perform surgery for ankle fracture might affect postoperative results and complications. METHODS: We used our multicenter database named TRON (Trauma Research Group of Nagoya). In all, 779 patients who underwent surgery for ankle fracture, who had no comorbidities were eligible. After exclusion, we analyzed 596 patients. We divided the patients into 2 groups according to whether they were operated on within 7 days after the injury with propensity score matching. RESULTS: The operative time of the delayed operation group (DO group) was significantly longer than that of the early operation group (EO group) (115.87 ± 56.59 vs 85.93 ± 34.58 minutes; P < .001). The rate of infection in the DO group was significantly higher than that of the EO group (16 patients [6.5%] vs 4 patients [1.6%]; P = .016). CONCLUSION: Waiting for more than a week to perform ankle surgery may lead to longer operative times and increased infection rates. LEVELS OF EVIDENCE: III.

DOI： 10.1177/19386400231164211

Free bone fragments are associated with the development of heterotopic ossification after hemiarthroplasty for femoral neck fracture: a retrospective observational study. Reviewed International journal Open Access

Hiroyuki Yokoi, Yasuhiko Takegami, Satoshi Ochiai, Takumi Miyachi, Tetsuya Urasaki, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 34 ( 8 ) page： 3947 - 3953 2024.12

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Heterotopic ossification (HO) can occur after hemiarthroplasty (HA) for femoral neck fractures (FNF). This study aimed to investigate the frequency and factors contributing to the development of HO after HA. METHODS: The study included data from 92 of 183 patients (26 male and 66 female) who sustained FNF and underwent HA between April 2019 and January 2022. HO was identified on postoperative radiographic images. Patient background, operative duration, blood loss, and presence of free bone fragments immediately after surgery were compared between the HO and non-HO groups. Statistical analyses included the independent-sample t-test for continuous variables and the chi-squared test for categorical variables. A multivariate logistic regression analysis was performed using HO as an objective variable. RESULTS: HO occurred in 50 of the 92 (54%) patients. There were no statistically significant differences in patient backgrounds. Univariate analysis revealed significantly longer mean operative duration and greater blood loss in the HO group. Free bone fragments in the immediate postoperative period were observed in 29 of 50 (58%) patients in the HO group and in 3 of 42 (7.1%) patients in the non-HO group, a statistically significant difference. Logistic regression analysis revealed that the presence of free bone fragments was an independent explanatory factor for HO development. CONCLUSION: The presence of free bone fragments immediately after surgery may be significantly associated with the development of HO. Therefore, it is necessary to sufficiently remove such fragments during surgery because they may trigger HO.

DOI： 10.1007/s00590-024-04083-6

Radiographic factors affecting contralateral knee alignment in patients with dysplastic hip osteoarthritis. Reviewed International journal

Shinya Tanaka, Yusuke Osawa, Yasuhiko Takegami, Yuto Ozawa, Shiro Imagama

The Knee Vol. 51 page： 249 - 257 2024.12

Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: Patients with dysplastic hip arthritis (DHA) often present with abnormal knee alignment. We investigate the factors influencing varus and valgus knee alignment on the contralateral side in patients with unilateral DHA. METHODS: 123 patients with unilateral DHA were enrolled between 2018 and 2022. Based on the hip-knee-ankle angle (HKAA), patients were divided into three groups: neutral group (HKAA <3° varus and valgus), varus group (>3° varus), and valgus group (>3° valgus). Demographics, radiographic parameters, and functional scores were compared between the groups. RESULTS: There were 58, 44, and 21 patients in the neutral, varus, and valgus group, respectively. The varus group had a varus HKAA and hip adduction angle in the affected hip and a large femoral offset in the healthy hip. The valgus group had a valgus HKAA and large hip adduction angle in the affected hip and a small femoral offset in the healthy hip. In addition, the valgus group presented with pelvic obliquity, expressed as an upper pelvic tilt on the affected side. Multivariate analysis identified a varus HKAA in the affected hip (odds ratio [OR], 0.64; 95% confidence interval [CI]: 0.51-0.79; p < 0.01) as a factor associated with the varus group, while pelvic obliquity (OR, 0.69; 95% CI: 0.53-0.89; p = 0.01) was associated with the valgus group. The varus and valgus groups had significantly worse functional scores than the neutral group. CONCLUSIONS: This study demonstrated that varus and valgus alignments of the contralateral knee with unilateral DHA were associated with radiographic parameters and hip function.

DOI： 10.1016/j.knee.2024.09.014

Total Hip Arthroplasty Using the Conjoined Tendon-Preserving Posterior Approach: The Modified Posterior Approach with a Minimum of 2-Year Follow-Up. Reviewed International journal Open Access

Yuto Ozawa, Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Hiroki Iida, Hiroto Funahashi, Shiro Imagama

Orthopaedic surgery Vol. 17 ( 1 ) page： 53 - 61 2024.11

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The conjoined tendon-preserving posterior (CPP) approach is a modified posterior approach for total hip arthroplasty (THA) that preserves the short external rotator muscles and most ischiofemoral ligaments. The objective of the present study was to compare the short-term clinical outcomes, complications, and imaging evaluations of CPP and posterior approaches in THA. METHODS: This retrospective study included 83 patients from May 2018 to September 2021: 36 patients with 42 hips who underwent THA with the CPP approach (CPP group) and 47 patients with 60 hips who underwent THA with the standard posterior approach (PA group) with a minimum of 2 years of follow-up. Assessment tools included operative times, blood loss, preoperative and last follow-up Harris Hip Scores (HHS), postoperative complications, and implant placement angles between the groups. Statistical analysis was performed using chi-square tests and T-tests. RESULTS: The CPP approach had a significantly longer operative time and greater blood loss compared to the PA group. Preoperative and postoperative HHS were not significantly different between groups. Considering complications, the PA group had one case each of dislocation and infection, and the CPP group had two cases of sciatic nerve palsy, but the difference was not significant. Cup anteversion, inclination and stem anteversion were not significantly different between groups. CONCLUSION: Functional outcomes, complication rates, and implant placement angles were comparable with the posterior approach, and the CPP approach has the potential to reduce postoperative dislocations. However, careful attention should be paid to sciatic nerve palsy during early initiation of the CPP approach, and this study did not demonstrate that the CPP approach was clearly superior to the posterior approach.

DOI： 10.1111/os.14194

The survey of bone allograft transplantation in a Japanese regional bone bank. Reviewed

Takamune Asamoto, Yusuke Osawa, Yasuhiko Takegami, Genta Takemoto, Daigo Komatsu, Taisuke Seki, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 6 ) page： 1528 - 1533 2024.11

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: In reconstructive surgery for large bone defects, the demand for bone allografts has increased over the years; however, it is unclear how the supply and demand in Japanese regional bone banks have evolved over time. This study investigated the 15-year supply and demand of bone allografts stored in a regional bone bank, along with assessing the screening process's effectiveness. METHODS: The target period was 15 years from April 2005 to March 2020. The period was subdivided into three 5-year periods: first, second, and third. The study items included the number of bone allografts donated, the number of bone allografts used, donor and user facilities, surgical methods using bone allografts, and the number of bone allografts discarded. We used the Cochran-Armitage test for statistical analysis. RESULTS: A total of 1852 bone allografts were donated to the bone bank, and a total of 1721 were used. A total of 677 bone allografts grafts were provided in the first period, 738 in the second period, and 525 in the third period, indicating a decreasing trend. The average number of allografts per surgery was 2.8 in the first, 3.1 in the second, and 1.7 in the third, showing a decreasing trend. Concerning the percentage of each surgery using bone allografts, spine fusion decreased in the third period but not significantly, whereas primary hip arthroplasty increased significantly in the third period. The total number of discarded bone allografts was 4.8% of the total number of donated bone allografts, largely because of a lack of screening tests. CONCLUSION: Although the number of allogeneic bone surgeries has been increasing over time, the number of allogeneic bone donations has shown a decreasing trend, and there is a need to develop a system that can provide surgeons with sufficient bone allografts.

DOI： 10.1016/j.jos.2023.11.001

Circulating miRNA-122 is associated with knee osteoarthritis progression: A 6-year longitudinal cohort study in the Yakumo study. Reviewed

Hiroto Funahashi, Yasuhiko Takegami, Yusuke Osawa, Hiroaki Nakashima, Shinya Ishizuka, Ryosuke Fujii, Hiroya Yamada, Koji Suzuki, Yukiharu Hasegawa, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 6 ) page： 1411 - 1416 2024.11

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: The association between knee osteoarthritis (OA) and miRNAs has been widely reported. However, the utility of miRNAs as predictors of knee osteoarthritis (KOA) progression in longitudinal studies has not been reported. We aimed to identify circulating miRNAs (c-miRNAs) associated with KOA progression in the general population and to examine their potential use as predictors of KOA progression. METHODS: In 2012 and 2018, 66 participants (128 knees) took part in a resident health check-up in the Yakumo study. If the KL classification progressed two or more levels, the patient was classified as having progressive OA. Quantitative real-time polymerase chain reaction was used to screen 21 c-miRNAs. The expression levels of those c-miRNAs were compared between the progressive OA group and non-progressive OA group using student-t-test. Logistic analysis was performed in c-miRNAs less than p < 0.10 in univariate analysis. RESULTS: The progressive OA group consisted of 78 knees. The results of the comparison between the progressive OA group and the non-progressive OA group showed that six c-miRNAs as follows; let7d (p = 0.030), c-miRNA-122 (p < 0.001), 150 (p = 0.070), 199 (p = 0.078), 21 (p = 0.016) and 320 (p = 0.093) were extracted as factors related to the progression of knee OA. In addition, logistic regression analysis identified c-miRNA-122 as an independent factor involved in the progression of knee osteoarthritis (odds ratio: 1.510, 95% confidence interval: 1.060-2.140, p = 0.023). The ROC curve showed by c-miRNA-122 for the progression of OA risk had an area under the curve of 0.702 (95% CI: 0.609-0.795). The threshold of c-miRNA-122 was -4.609. CONCLUSION: The expression level of c-miRNA-122 was associated with the risk of KOA progression in community dwelling Japanese people.

DOI： 10.1016/j.jos.2023.10.004

Predictive factors for reoperation after periprosthetic femoral fracture: A retrospective multicenter (TRON) study. Reviewed

Manato Iwata, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroshi Kurokawa, Hideomi Takami, Satoshi Terasawa, Tetsuro Takatsu, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 6 ) page： 1445 - 1450 2024.11

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The surgical treatment of periprosthetic femoral fracture (PFF) can be technically demanding and it is associated with high rates of complications and repeat surgery. However, repeat surgery is uncommon and few studies have examined survival and the functional prognosis following reoperation after the surgical treatment of PFF. We aimed to estimate the rate of reoperation for any reason, to determine the survival rate after reoperation for PFF, and to identify predictors associated with reoperation after PFF surgery in a multicenter (TRON group) study. METHODS: Two hundred forty-six patients were admitted for treatment of PFF. After excluding patients managed conservatively and those with Vancouver type A fracture, we analyzed 184 patients. Unadjusted risk ratios (RRs) were calculated, and multiple logistic regression was used to calculate adjusted RRs. We used the Kaplan-Meier method to create survival curves and a log-rank test to determine survival from the date of repeat surgery. RESULTS: Fifteen of the 184 patients (8.2 %) underwent reoperation after PFF surgery. The 1-year survival rate after reoperation for PFF was 66.7 % (11 of 15). Vancouver B3 and Vancouver C were identified as independent risk factors for reoperation after PFF surgery (Vancouver B3: Risk ratio [RR] 19.0, 95 % CI 1.10-329 P < 0.001; Vancouver C: RR 13.3, 95 % CI 1.4-123.0, P = 0.023). CONCLUSION: The reoperation rate after PFF surgery and the mortality after reoperation PFF surgery were relatively high. The fracture type is associated with reoperation after PFF surgery.

DOI： 10.1016/j.jos.2023.11.016

The prevalence and characteristics of diffuse idiopathic skeletal hyperostosis in the community-living middle-aged and elderly population: The Yakumo study. Reviewed

Kazuma Ohshima, Hiroaki Nakashima, Naoki Segi, Sadayuki Ito, Jun Ouchida, Yasuhiko Takegami, Shinya Ishizuka, Yukiharu Hasegawa, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 6 ) page： 1346 - 1352 2024.11

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The incidence of diffuse idiopathic skeletal hyperostosis (DISH) is increasing with the aging of the population. Asymptomatic DISH can decrease the spinal range of motion (ROM) and cause fractures. However, the prevalence or physical function of patients with DISH before experiencing fractures and other serious conditions is unclear. This study aimed to investigate the prevalence of DISH in the community residents on the basis of age and sex and characterize their physical function, ROM, and bone fragility. METHODS: The subjects were community volunteers who attended a health checkup in 2018 and 2019. Overall, 455 subjects (mean age, 64.2 ± 9.7 years; 177 men) were included for analysis. We performed whole-spine lateral radiography for detecting DISH according to the criteria reported by Resnick. We compared the age, sex, body mass index (BMI), results of muscle strength and walking tests, ROM measured by SpinalMouse®, and quantitative ultrasound (QUS) of calcaneus with and without DISH. RESULTS: DISH was detected in 83 (18.2%) cases. The DISH group was older (69.8 y.o. vs. 63.0 y.o.; p < 0.05) and comprised more men (prevalence: men, 27.7%; women, 12.2%; p < 0.001). BMI was high in the DISH group (24.8 vs. 23.3 kg/m2, p < 0.05). SpinalMouse measurements showed the DISH group had a significantly decreased ROM in the lumbar spine (43.2°, 57.2°, p < 0.05). The DISH group had a significantly lower T-score on the QUS measurement in the calcaneus (-2.0, -1.5, p < 0.05). There were, however, no significant differences between groups in both muscle strength test and walking test. CONCLUSION: Subjects with DISH had decreased ROM in the lumbar spine and bone mineral density in calcaneal QUS. However, physical functions such as muscle strength and walking ability were similar among subjects with and without DISH without subjective symptoms.

DOI： 10.1016/j.jos.2023.10.005

Prevalence and treatment rates of osteoporosis among individuals with rotator cuff tears. Reviewed International journal

Itaru Kawashima, Shinya Ishizuka, Hiroki Oba, Takefumi Sakaguchi, Hiroaki Nakashima, Yasuhiko Takegami, Shiro Imagama

Journal of shoulder and elbow surgery Vol. 33 ( 11 ) page： e606 - e609 2024.11

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The relationship between osteoporosis and rotator cuff tears has been reported previously. However, the treatment rate of osteoporosis in individuals with rotator cuff tear is still unknown. The aim of this study was to investigate the prevalence and treatment rate of osteoporosis in individuals with rotator cuff tears. METHODS: In this cross-sectional study, we enrolled 207 participants. Participants underwent comprehensive assessments, including shoulder ultrasonographic examinations and quantitative ultrasound measurements for bone status evaluation. Osteoporosis diagnosis was predicated on a calcaneus ultrasound bone densitometry, and the cutoff value was set as a T score of -1.455, with reference to a previous report. RESULTS: One hundred fifty-six participants were classified as individuals without rotator cuff tears (group A), and 51 participants were classified as those with (group B). The mean age in group A was significantly lower than that in group B (63 ± 10 vs. 68 ± 9, respectively; P = .003). In terms of the T score examined by quantitative ultrasound, the mean T score in group A was significantly higher than that in group B (-1.4 ± 1.3 vs. -1.9 ± 1.6, respectively; P = .0412). The percentage of subjects with a T score of -1.455 or less in group B was 60.8% (31/51). The proportion of subjects with a T score of -1.455 or less undergoing osteoporosis treatment was 14.5% (12/83) in group A and 12.9% (4/27) in group B, showing no significant difference. CONCLUSIONS: Participants with a rotator cuff tear had relatively high prevalence of osteoporosis. Among those with both a rotator cuff tear and osteoporosis, the proportion receiving osteoporosis treatment was l2.9%, a very low rate.

DOI： 10.1016/j.jse.2024.02.026

What Are the Sex-Based Differences of Acetabular Coverage Features in Hip Dysplasia? Reviewed International journal

Hiroto Funahashi, Yusuke Osawa, Yasuhiko Takegami, Hiroki Iida, Yuto Ozawa, Hiroaki Ido, Shiro Imagama

Clinical orthopaedics and related research Vol. 482 ( 11 ) page： 1971 - 1983 2024.11

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Eccentric rotational acetabular osteotomy is performed to prevent osteoarthritis caused by developmental dysplasia of the hip (DDH). To achieve sufficient acetabular coverage, understanding the characteristics of acetabular coverage in DDH is necessary. However, the features of acetabular coverage in males with DDH remain unclear. We thought that the differences in acetabular coverage between females and males might be associated with the differences in pelvic morphology between the sexes. QUESTIONS/PURPOSES: (1) What are the differences in the acetabular coverage between females and males with DDH? (2) What are the differences in the rotations of the ilium and ischium between females and males with DDH? (3) What is the relationship between the rotation of the ilium and ischium and the acetabular coverage at each height in females and males with DDH? METHODS: Between 2016 and 2023, 114 patients (138 hips) underwent eccentric rotational acetabular osteotomy at our hospital. We excluded patients with Tönnis Grade 2 or higher, a lateral center-edge angle of 25º or more, and deformities of the pelvis or femur, resulting in 100 patients (122 hips) being included. For female patients (98 hips), the median (range) age was 40 years (10 to 58), and for the male patients (24 hips), it was 31 years (14 to 53). We used all patients' preoperative AP radiographs and CT data. The crossover sign, posterior wall sign, and pelvic width index were evaluated in AP radiographs. The rotation of the innominate bone in the axial plane was evaluated at two different heights, specifically at the slice passing through the anterior superior iliac spine and the slice through the pubic symphysis and ischial spine in CT data. Furthermore, we evaluated the anterior and posterior acetabular sector angles. Comparisons of variables related to innominate bone measurements and acetabular coverage measurements between females and males in each patient were performed. The correlations between pelvic morphology measurements and acetabular coverage were evaluated separately for females and males, and the results were subsequently compared to identify any sex-specific differences. For continuous variables, we used the Student t-test; for binary variables, we used the Fisher exact test. A p value less than 0.05 was considered statistically significant. RESULTS: In the evaluation of AP radiographs, an indicator of acetabular retroversion-the crossover sign-showed no differences between the sexes, whereas the posterior wall sign (females 46% [45 of 98] hips versus males 75% [18 of 24] hips, OR 3.50 [95% confidence interval (CI) 1.20 to 11.71]; p = 0.01) and pelvic width index less than 56% (females 1% [1 of 98] versus males 17% [4 of 24], OR 18.71 [95% CI 1.74 to 958.90]; p = 0.005) occurred more frequently in males than in females. There were no differences in the iliac rotation parameters, but the ischium showed more external rotation in males (females 30° ± 2° versus males 24° ± 1°; p < 0.001). Regarding acetabular coverage, no differences between females and males were observed in the anterior acetabular sector angles. In contrast, males showed smaller values than females for the posterior acetabular sector angles (85° ± 9° versus 91° ± 7°; p = 0.002). In females, a correlation was observed between iliac rotation and acetabular sector angles (anterior acetabular sector angles: r = -0.35 [95% CI -0.05 to 0.16]; p < 0.001, posterior acetabular sector angles: r = 0.42 [95% CI 0.24 to 0.57]; p < 0.001). Similarly, ischial rotation showed a correlation with both acetabular sector angles (anterior acetabular sector angles: r = -0.34 [95% CI -0.51 to -0.15]; p < 0.001 and posterior acetabular sector angles: r = 0.45 [95% CI 0.27 to 0.59]; p < 0.001). Thus, in females, we observed that external iliac rotation and ischial internal rotation correlated with increased anterior acetabular coverage and reduced posterior coverage. In contrast, although acetabular coverage in males showed a correlation with iliac rotation (anterior acetabular sector angles: r = -0.55 [95% CI -0.78 to -0.18]; p = 0.006 and posterior acetabular sector angles: r = 0.74 [95% CI 0.48 to 0.88]; p < 0.001), no correlation was observed with ischial rotation. CONCLUSION: In males, acetabular retroversion occurs more commonly than in females and is attributed to their reduced posterior acetabular coverage. In females, an increase in the posterior acetabular coverage was correlated with the external rotation angle of the ischium, whereas in males, no correlation was found between ischial rotation and posterior acetabular coverage. In treating males with DDH via eccentric rotational acetabular osteotomy, it is essential to adjust bone fragments to prevent inadequate posterior acetabular coverage. Future studies might need to investigate the differences in acetabular coverage between males and females in various limb positions and consider the direction of bone fragment rotation. CLINICAL RELEVANCE: Our findings suggest that males with DDH exhibit acetabular retroversion more frequently than females, which is attributed to the reduced posterior acetabular coverage observed in males. The smaller posterior acetabular coverage in males might be related to differences in ischial morphology between sexes. During eccentric rotational acetabular osteotomy for males with DDH, adequately rotating acetabular bone fragments might be beneficial to compensate for deficient posterior acetabular coverage.

DOI： 10.1097/CORR.0000000000003126

Preoperative hip abductor strength predicts discharge destination after total hip arthroplasty. Reviewed International journal

Shusuke Nojiri, Azusa Kayamoto, Chiaki Terai, Shinya Tanaka, Yusuke Osawa, Yasuhiko Takegami

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 35 ( 1 ) page： 5 - 5 2024.11

Authorship：Last author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This study aimed to clarify the association between preoperative physical function and discharge destination after total hip arthroplasty (THA). METHODS: This retrospective study included patients who underwent primary unilateral THA for hip osteoarthritis. Preoperative physical function was assessed via maximal isometric muscle strength (hip abduction and knee extension) and comfortable walking speed. The patients were divided into two groups according to the discharge destination (home or transfer to other facilities). Multivariate logistic regression analysis was used to identify preoperative physical function associated with discharge destination. RESULTS: Of the 174 patients, 120 were discharged directly to home, and 54 were transferred to other facilities. Those transferred to other facilities were significantly older, more likely to live alone, and had a longer operation time. In addition, they demonstrated lower hip abductor strength on both sides and lower knee extensor strength on the operative side. Multivariate logistic regression analysis revealed that hip abductor strength on both sides, not knee extensor strength, was independently associated with the discharge destination. The largest area under the receiver operating characteristic curve was 0.668 for the hip abductor strength of the contralateral side. The optimal cutoff point was revealed to be 0.035 kgf·m/kg and 0.031 kgf·m/kg for the operative and contralateral sides, respectively. CONCLUSIONS: Preoperative hip abductor strength, particularly on the contralateral side with a cutoff value of 0.031 kgf·m/kg, could be a predictor of discharge destination after unilateral THA. Our findings would be useful in planning rehabilitation programs.

DOI： 10.1007/s00590-024-04119-x

Elderly trochanteric fracture outcomes: Unveiling the risks of excessive postoperative sliding - A retrospective multicenter (TRON group) investigation. Reviewed

Makoto Suzuki, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroaki Nakasima, Kenichi Mishima, Hiroaki Kumagai, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2024.10

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Intramedullary nailing (IMN) for femoral trochanteric fractures (FTF) is the primary surgical intervention. Excessive lag screw sliding (ES) of the femoral neck screw sometimes occurs. This multicenter investigation sought to 1) determine the prevalence of ES, 2) evaluate the relationship between ES and postoperative complications, and 3) identify the factors of ES in elderly patients with FTF undergoing IMN. METHODS: From 2016 to 2020, 1448 patients with FTF were treated using a short IMN across 11 institutions (TRON group). Upon applying exclusion criteria, 519 patients (127 men, 392 women; mean age, 84.4 years) were included. The postoperative sliding distance was measured immediately after surgery and at final follow-up. A sliding distance of ≥8 mm categorized patients as having ES. We identify the factors contributing to ES using the logistic regression analysis, with a p < 0.05 as statistical significance. RESULTS: ES was observed in 116 patients (22.4 %). Patients with ES had a higher incidence of postoperative cut-out and peri-implant fracture. Logistic regression analysis showed that achieving optimal reduction in both AP and lateral views (odds ratio (OR) 0.48, p = 0.0012) and the use of a double screw system or twin screws with integrated locking mechanism significantly reduced the risk of ES (OR 0.27, 0.17; p = 0.0027, <0.001). CONCLUSIONS: The incidence rate of ES was 22.4 %. ES was associated with a higher risk of postoperative complications. The surgeons should aim for optimal reduction and use a double screw or twin screws with an integrated interlocking mechanism as the implant of choice.

DOI： 10.1016/j.jos.2024.09.003

Risk factors for nonunion in femoral neck fracture patients with internal fixation: A multicenter (TRON group) retrospective study. Reviewed

Shingo Kurahashi, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroaki Nakashima, Kenichi Mishima, Kenichi Yamauchi, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2024.10

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: Femoral neck fractures (FNFs) are common in elderly individuals. When minimally displaced, they are typically treated with internal fixation. Nonunion is a complication of internal fixation of FNF, that sometimes necessitates reoperation. Radiographic parameters, including the Pauwels angle and posterior tilt angle, are risk factors for nonunion. However, these parameters are assessed solely in a two-dimensional context. We developed a novel radiographic parameter named the "Kindex." This multicenter investigation aimed to identify risk factors for nonunion following FNF fixation and evaluate the validity of this index. METHODS: This retrospective multicenter study collected data from 939 FNF patients who underwent internal fixation between 2016 and 2020 at 11 facilities (TRON group). The following exclusion criteria were applied: age <65, insufficient data, and Garden Stage III or IV fracture. Patient data, including age, sex, BMI, ASA classification, alcohol and smoking history, and comorbidities, were recorded. Radiographic measurements of the Pauwels angle and posterior tilt angle at the time of injury were used to calculate the Kindex. Correlations between the Pauwels angle, posterior tilt angle, Kindex, and nonunion were evaluated. A multivariate logistic regression analysis was performed to investigate independent risk factors for nonunion. A receiver operating characteristic (ROC) analysis was performed to determine the cutoff value of the Kindex, and the area under the curve (AUC) was calculated. RESULTS: The study included 594 patients (males, n = 151; females, n = 443; average age, 80.9 years). Nonunion was observed in 13 cases (2.2 %). While the Pauwels angle and posterior tilt angle did not show significant correlations, the Kindex exhibited strong correlations with both parameters. In the multivariate analysis, the Kindex and renal impairment were independent risk factors for nonunion (Kindex: OR 1.06, p = 0.015; renal impairment: OR 1.48, p = 0.021). In the ROC analysis, a Kindex of 50 was identified as the optimal cutoff value (AUC 0.72). CONCLUSION: The nonunion rate after internal fixation of FNF was 2.2 %. Renal impairment and the Kindex were identified as independent risk factors. The Kindex at the time of injury may serve as a novel radiographic parameter to consider when evaluating the need for internal fixation in FNF cases.

DOI： 10.1016/j.jos.2024.09.002

Peri-implant fractures after Intramedullary fixation for femoral trochanteric fracture: a multicenter (TRON Group) study. Reviewed International journal

Takuya Kaneda, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroaki Nakashima, Kenichi Mishima, Marie Mabuchi, Shiro Imagama

European journal of trauma and emergency surgery : official publication of the European Trauma Society Vol. 50 ( 5 ) page： 2587 - 2594 2024.10

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: With the rise in elderly populations, the incidence of femoral trochanteric fractures has also increased. Although intramedullary nail therapy is commonly used, the incidence of peri-implant fractures (PIFs) as a complication and its associated factors are not fully understood. The purpose of this study was to determine the incidence of PIFs and treatment strategies and outcomes. METHODS: A retrospective study across 11 hospitals from 2016 to 2020 examined 1855 patients with femoral trochanter fracture. After excluding 69 patients treated without intramedullary nailing, 1786 patients were analyzed. Parameters studied included age, sex, body mass index, medical history, and treatment methods. PIFs were categorized using the Chan classification. Treatment outcomes and patient mobility were assessed using the Parker Mobility Score, and postoperative complications and one-year survival data were compiled. RESULTS: The incidence of PIFs was 8 in 1786 cases. Chan classification showed 1 case of N1A, 6 of N2A, and 1 of N2B. Only the type N1 case was a transverse fracture, whereas all cases of type N2 were oblique fractures. Among these cases, five patients had fractures extending to the upper part of the femoral condyle. The patient with N1A and one bedridden patient with N2A fracture underwent conservative treatment, one patient with N2A in which the fracture did not extend to the condyle was treated with nail replacement, and 5 patients (N2A: 4, N2B: 1) with fractures extending to the condyle were treated with additional plate fixation. All patients had survived at one year after treatment for PIF, and no reoperations were required. CONCLUSIONS: The incidence of PIF was very low (0.45%). Of the 6 PIF cases, excluding the bedridden patients, the treatment of choice for PIF was an additional plate if the fracture line extended to the femoral condyle; otherwise, the nail was replaced. All patients achieved bony fusion. LEVEL OF EVIDENCE: Therapeutic Level IV.

DOI： 10.1007/s00068-024-02567-y

Accelerometer-based portable navigation system shows no superior accuracy over pelvic alignment guide for acetabular cup placement in total hip arthroplasty in lateral decubitus position. Reviewed International journal

Masanori Okamoto, Yasuhiko Takegami, Yusuke Osawa, Shinya Tanaka, Tatsuya Nobori, Shiro Imagama

Archives of orthopaedic and trauma surgery Vol. 144 ( 11 ) page： 4849 - 4856 2024.9

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Total hip arthroplasty (THA) using a portable navigation system (PNS) incurs costs per procedure. However, it does not require a large console. This study aimed to compare the accuracy of acetabular cup placement using a pelvic alignment guide (PAG) attached to the pelvis and an accelerometer-based PNS in THA performed in the lateral decubitus position. METHODS: We retrospectively analyzed 100 hips that underwent primary THA in the lateral decubitus position between July 2018 and January 2021. The PAG was used in 50 hips, whereas the PNS was used in the other 50. Cup placement accuracy was measured using postoperative computed tomography scans, comparing errors in inclination and anteversion angles. The surgical time, blood loss, and complications were recorded. The follow-up period was at least 2 years in all cases. RESULTS: The mean absolute error of the inclination angle was similar between the groups (the PAG group: 3.7° ± 2.3° [range, 0.0-9.0]; the PNS group: 3.7° ± 2.3° [range, 0.2-10.5], p = 0.705). The mean absolute error of the anteversion angle was significantly smaller in the PAG group than in the PNS group (3.0° ± 2.4° [range, 0.0-9.7] vs. 6.5° ± 4.8° [range, 0.3-17.3], p < 0.001). The PAG group had a higher proportion of hips within 5° and 10° of the target angle (64 vs. 42%, P = 0.028, and 100 vs. 74%, p < 0.001, respectively). The PNS group had six hips with anteversion errors of 15° or more. Surgical time and blood loss were lower in the PAG group. The PNS group had one dislocation, whereas the PAG group did not. CONCLUSION: The accelerometer-based PNS did not demonstrate superior cup alignment accuracy compared to the PAG in THA performed in the lateral decubitus position. This finding informs surgeons that computer-assisted surgery is not necessarily superior to conventional THA using a PAG.

DOI： 10.1007/s00402-024-05571-4

Early surgery within 48 hours of admission for hip fracture did not improve 1-year mortality in Japan: a single-institution cohort study. International journal

Hiroki Iida, Yasuhiko Takegami, Yoshihito Sakai, Tsuyoshi Watanabe, Yusuke Osawa, Shiro Imagama

Hip international : the journal of clinical and experimental research on hip pathology and therapy Vol. 34 ( 5 ) page： 660 - 667 2024.9

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: Early surgery for hip fracture, within 48 hours of hospital admission, is effective in reducing mortality. However, the average preoperative waiting time for hip fractures in Japan is 4.5 days and the 1-year mortality rate after a hip fracture is 10% in Japan. This study aimed to investigate whether early surgery, within 48 hours, could reduce the 1-year mortality rate in patients with hip fractures in Japan. METHODS: This cohort study involved 402 consecutive patients with hip fractures who underwent surgical treatment between January 2013 and September 2019. The exclusion criteria were an age of <60 years and in-hospital injury. A total of 389 patients were included in this study. The patients were divided into two groups: those who underwent early surgery within 48 hours of admission (early group) and those who di not undergo early surgery (delayed group). We compared patient characteristics and treatment outcomes between the 2 groups. RESULTS: A comparison of patient characteristics revealed that the early group had lower hemoglobin levels (P=0.046), lower C-reactive protein levels (P = 0.031), lower numbers of patients with weekend hospitalization, lower numbers of patients with a history of using medications that may cause bleeding (P < 0.01), and who received general anaesthesia (P < 0.01). However, there were no significant differences with regard to the other variables between the 2 groups. A treatment outcome analysis showed that the early group had shorter waiting times for surgery (P < 0.01) and shorter stays in acute-care wards (P < 0.01). However there were no differences in the total hospital stay, Barthel index at discharge, home discharge rates, in-hospital mortality rates, and 1-year mortality. CONCLUSION: Our findings indicate that early surgery did not reduce the 1-year mortality rate in older patients with hip fractures in Japan.

DOI： 10.1177/11207000241248836

Trochanteric rotational osteotomy in patients with concomitant osteonecrosis of the femoral head and trochanter: A case report Open Access

Hiroto Funahashi, Yusuke Osawa, Yasuhiko Takegami, Shiro Imagama

Journal of Orthopaedic Reports Vol. 3 ( 3 ) 2024.9

Risk factors for residual pelvic obliquity one year after total hip arthroplasty. Reviewed International journal Open Access

Yuto Ozawa, Yusuke Osawa, Yasuhiko Takegami, Hiroki Iida, Genta Takemoto, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 34 ( 6 ) page： 3319 - 3327 2024.8

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: It is not uncommon for patients with hip disorders to present with pelvic obliquity (PO), and residual PO after total hip arthroplasty (THA) may not only affect hip joint function but also cause adjacent intervertebral joint disorders. This study aimed to investigate the postoperative PO impact on clinical outcomes and risk factors by comparing patients who had PO after THA to those who did not. METHODS: A single-center, retrospective cohort study was conducted. A total of 103 patients who underwent THA were included in this study from 2018 to 2020. Demographics, functional outcomes, and spinopelvic parameters were compared between post-THA PO of less than 2° (NT group, 55 patients) and PO of 2° or more (O group, 48 patients). Multivariate analysis was performed using factors with significant differences in univariate analysis. RESULTS: Postoperative Harris Hip Score Activity was significantly lower in the T group than in the NT group (p = 0.031). Preoperative PO was smaller in the NT group than in the T group (p = 0.001). Preoperative lumbar bending range (LBR) was significantly more flexible in the NT group than in the T group. In the logistic regression analysis, Age (odds ratio 0.957, 95% CI 0.923-0.993, p = 0.020), preoperative PO (odds ratio 1.490, 95% CI 1.100-2.020, p = 0.001), and LBR (odds ratio 0.848, 95% CI 0.756-0.951, p = 0.005) were found to be significant factors. CONCLUSION: Younger age and large preoperative PO, and poor lumbar spine mobility were identified as risk factors for residual postoperative PO.

DOI： 10.1007/s00590-024-04060-z

Rebuttal submission to "Failure of AI-driven diagnostic tool: lessons and strategies to prevent patient harm". Invited Reviewed International journal

Yasuhiko Takegami, Takamune Asamoto

Archives of osteoporosis Vol. 19 ( 1 ) page： 75 - 75 2024.8

Computer simulation study of cementless cup placement for dysplastic hip osteoarthritis using subluxation percentage of Crowe classification. Reviewed International journal

Keiji Otaka, Yusuke Osawa, Yasuhiko Takegami, Hiroki Iida, Yuto Ozawa, Hiroto Funahashi, Shiro Imagama

Journal of orthopaedic research : official publication of the Orthopaedic Research Society Vol. 42 ( 8 ) page： 1801 - 1809 2024.8

Language：English Publishing type：Research paper (scientific journal)

It is often difficult to achieve adequate bone coverage of the cup in total hip arthroplasty in cases of severe developmental dysplasia of the hip (DDH). This study aimed to evaluate the relationship between subluxation percentage of Crowe classification and cup center-edge (cup-CE) angle to investigate whether subluxation percentage according to the Crowe classification is a useful indicator for cementless cup placement. Cementless cup placement was simulated in 77 women with DDH in 91 hips (Crowe I, 35 hips; Crowe II, 35 hips; and Crowe III, 21 hips) using computed tomography-based computer simulation software. The cups were placed at the anatomic hip center (AHC) and 10-mm high hip center (HHC). The relationship between the subluxation percentage and cup-CE angle was evaluated using Spearman's rank correlation coefficient. In addition, the cutoff values for the subluxation percentage that satisfied a cup-CE angle ≥0° were determined using the receiving operating characteristic curve. The cup-CE angle was negatively correlated with the subluxation percentage in both AHC and 10-mm HHC (correlation coefficient ρ = -0.542 [p < 0.01] and -0.704 [p < 0.01], respectively). The cutoff values for subluxation percentage that satisfied a cup-CE angle ≥0° were 56.1% and 73.6% for AHC and 10-mm HHC, respectively. Cementless cup placement in AHC is difficult in cases with the subluxation percentage ≥56.1%, and HHC reconstruction or femoral structural autograft technique should be considered as an alternative. Moreover, placement at 10 mm above AHC is difficult in cases with subluxation percentage ≥73.6%.

DOI： 10.1002/jor.25819

Factors related to collapse progression in Japanese Investigation Committee classification type B osteonecrosis of the femoral head. Reviewed International journal

Hiroaki Ido, Yusuke Osawa, Yasuhiko Takegami, Funahashi Hiroto, Yuto Ozawa, Shiro Imagama

International orthopaedics Vol. 48 ( 8 ) page： 2033 - 2040 2024.8

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This study aimed to identify factors related to collapse progression in Japanese Investigation Committee classification type B osteonecrosis of the femoral head (ONFH) and to identify patients who would benefit from surgical treatment. METHODS: This study included 41 patients (56 hips) with type B ONFH with a minimum follow-up of three years. Based on a ≥ 3 mm collapse progression in ONFH, we categorised patients into two groups: collapse progression and no collapse progression. Sagittal and coronal computed tomography images were used to measure the necrotic region relative to the intact femoral head diameter. The ratios of the necrotic regions of transverse and vertical diameter in coronal and sagittal images are defined as mediolateral transverse and mediolateral vertical, anteroposterior transverse and anteroposterior vertical, respectively. Demographic data and these imaging findings were compared between the two groups. We established a cut-off value for predicting collapse progression through receiver operating characteristic analysis and determined survival rates. RESULTS: Type B ONFH had a 17.8% collapse progression rate. The mediolateral transverse, mediolateral vertical, anteroposterior transverse, and anteroposterior vertical were significantly higher in the collapse progression group (P < 0.01). Mediolateral transverse was an independent risk factor of collapse progression (hazard ratio, 1.27; 95% confidence interval, 1.03-1.57; P = 0.03), with an optimal cut-off of 45.6%. The 5-year survival rates with collapse progression as the endpoints were 57.0 and 94.9% in the mediolateral transverse of ≥ 45.6 and < 45.6%, respectively. CONCLUSION: A mediolateral transverse of ≥ 45.6% predicts collapse progression in patients with type B ONFH.

DOI： 10.1007/s00264-024-06221-5

Characteristics of pelvic obliquity in dysplastic hip osteoarthritis. Reviewed International journal Open Access

Yuto Ozawa, Yusuke Osawa, Yasuhiko Takegami, Hiroto Funahashi, Shinya Tanaka, Shiro Imagama

Archives of orthopaedic and trauma surgery Vol. 144 ( 8 ) page： 3813 - 3821 2024.8

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Factors affecting direction of pelvic obliquity (PO) in dysplastic hip osteoarthritis (DHOA) remains unclear. This retrospective cohort study evaluates morphological characteristics, spinal alignment, and hip function in patients with unilateral DHOA. METHODS: Between 2018 and 2022, 104 patients with unilateral DHA were enrolled. Patients were categorized into flat PO (F-PO group; PO < 2°), affected side PO (A-PO group; PO downward by ≥ 2°), and unaffected side PO (U-PO group; PO upward by ≥ 2°). Demographics, radiographic hip and lower limb parameters, spinal parameters, and functional scores were compared between the groups. RESULTS: There were 39, 44, and 21 patients in the F-PO, A-PO, and U-PO group, respectively. The subluxation percentage of Crowe classification showed a significant difference among the three groups. The femoral head lateralization distance was significantly greater in the U-PO group than in the F-PO and A-PO groups. Furthermore, the hip adduction angle was significantly lower in the A-PO group than in the F-PO and U-PO groups. The lumbar scoliosis angle was significantly different between the groups. In multivariate analysis, hip adduction angle was extracted as an independent factor associated with the A-PO. Age, subluxation percentage, and hip adduction angle were identified as independent factors associated with the U-PO. Harris hip score was significantly poorer in U-PO group than in F-PO group. CONCLUSIONS: Hip adduction angle influenced A-PO, while age, subluxation percentage, and hip adduction angle influenced U-PO; lumbar scoliosis angle was associated with PO direction. U-PO patients had poorer functional scores, indicating the impact of hip contracture and subluxation on PO direction in DHOA.

DOI： 10.1007/s00402-024-05476-2

Low and high body mass index and lower numbers of screws in the articular segment are risk factors for non-union of distal humeral fractures in the elderly: A multi-center retrospective study (TRON study). Reviewed International journal

Kenya Iwase, Yasuhiko Takegami, Katsuhiro Tokutake, Yasutaka Oshika, Hiroki Yokoyama, Kohei Tanaka, Tadahiro Sakai, Shiro Imagama

Shoulder & elbow Vol. 16 ( 3 ) page： 312 - 320 2024.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Distal humerus fracture in the elderly is a challenging fracture for orthopedic surgeons. Non-union is one of the serious complications of distal humerus fracture after surgery. This retrospective multicenter study aimed to estimate the incidence of distal humeral non-union after open reduction and internal fixation, determine factors related to non-union, and compare the postoperative results of cases with non-union to cases with the union. METHODS: Among 423 patients diagnosed with distal humeral fracture and who were treated by surgical therapy in 2010-2020 from our database called TRON. Only 190 subjects met the inclusion criteria. We performed a logistic regression analysis with the presence of non-union as the response variable to examine risk factors. We compare the Mayo Elbow Performance Scores of cases with non-union to cases with the union. RESULTS: Non-union occurred after surgery in 15 patients (7.9%). The logistic regression analysis showed that body mass index<20 kg/m2 and ≥25 kg/m2, and ≤3 screws in the articular segment were significant explanatory factors for non-union (odds ratio 10.4 and 47.8, respectively). The Mayo Elbow Performance Scores were significantly worse in patients with non-union. DISCUSSION: Low and high body mass index and three or fewer screws in the articular segment might be risk factors for non-union of distal humerus fracture in the elderly. Non-union is associated with poor clinical outcomes.

DOI： 10.1177/17585732221131923

Sacroiliac joint fusion in patients with ankylosing spondylitis is associated with hip involvement. Reviewed

Hiroaki Ido, Yusuke Osawa, Yasuhiko Takegami, Kenji Kishimoto, Daisuke Kihira, Mochihito Suzuki, Shuji Asai, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 4 ) page： 939 - 944 2024.7

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: Ankylosing spondylitis (AS) is a progressive inflammatory disease that affects the axial skeleton, and often associated with hip involvement. However, the causative factors for radiological hip involvement in patients with AS are not well characterized. This study aimed to investigate the factors associated with hip involvement in patients with AS. METHODS: Sixty-seven patients (134 hips) diagnosed with AS who qualified the modified New York criteria at our institution between January 2005 and June 2022 were enrolled. Patients were divided into two groups: the hip involvement group (BASRI-hip score ≥2 points) and the normal group (BASRI-hip score <2 points). Demographic, clinical and radiographic characteristics were compared between the two groups. RESULTS: Twenty-six patients (38.8%) had radiological hip involvement, of which 23 (88.5%) patients were male. There were significant between-group differences with respect to sacroiliac joint fusion, crossover sign, high centre edge angle and low sharp angle (P < 0.05). On logistic regression analysis, older age, sacroiliac joint fusion and pincer type were identified as independent risk factors for hip involvement. CONCLUSION: AS with hip involvement was significantly more likely to involve sacroiliac joint fusion, which suggested that mechanical stress in adjacent joints and reduced spinopelvic range of motion may influence hip involvement.

DOI： 10.1016/j.jos.2023.06.012

Risk factors for lateralization or superiorization of the center of the femoral head in eccentric rotational acetabular osteotomy. Reviewed

Masanori Okamoto, Yasuhiko Takegami, Yusuke Osawa, Hiroki Iida, Hiroto Funahashi, Taisuke Seki, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 4 ) page： 1009 - 1014 2024.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This study aimed to clarify the factors that cause the lateralization and superiorization of the femoral head after eccentric rotational acetabular osteotomy (ERAO) by examining the three-dimensional morphology of the osteotomy site using computed tomography (CT). METHODS: This study included 52 patients who underwent ERAO for hip dysplasia. Postoperatively, the center of the femoral head was measured for lateralization and superiorization. We defined the iliac and sciatic osteotomy angles in the coronal and axial CT planes, respectively. The surgical factors for lateralization and superiorization were analysed using multiple logistic regression analysis. We also analysed the relationship between the femoral head relocation and clinical outcomes (as assessed using Japanese Orthopaedic Association (JOA) scores). RESULTS: Thirty-five patients had hips with lateralized femoral heads, and 25 patients' femoral heads were superiorized. Logistic regression analysis revealed that a higher osteotomy angle of the ilium in the coronal plane served as a significant predictor of superiorization of the femoral head. Similarly, a larger osteotomy angle of the ischium in the axial plane and the amount of change in the lateral centre edge angle were identified as predictors of lateralization. A weak negative correlation was observed between the amount of lateralization and the JOA score. CONCLUSION: Large osteotomy angles in the superior and posterior aspects of the acetabulum carry a risk of superiorization and lateralization of the center of the femoral head. Surgeons should be aware of the need to chisel through the internal plate to achieve the results described in the ERAO theory. STUDY DESIGN: A single-center, retrospective study.

DOI： 10.1016/j.jos.2023.06.010

Does Preoperative Manual Reduction (Omoto Technique) Affect Surgical Outcomes for Calcaneal Fractures? A Multicenter (TRON Group) Retrospective Study. Reviewed International journal

Hidetane Takahashi, Yasuhiko Takegami, Katsuhiro Tokutake, Yu Takahashi, Mihoko Kato, Marie Mabuchi, Shiro Imagama

The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons Vol. 63 ( 4 ) page： 450 - 455 2024.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

The Omoto technique is a well-known method that is commonly used for noninvasive manual repair of calcaneal fractures. However, there have been no detailed studies on its clinical outcomes in preoperative closed reduction for surgical cases. This multicenter retrospective study aimed to compare the clinical and radiographic outcomes of calcaneal fractures treated with and without the preoperative Omoto technique, assessing its effectiveness. We extracted 335 patients with calcaneal fracture who underwent surgery between 2015 and 2020 from our multicenter database, named TRON. We evaluated the clinical outcomes using the American Orthopedic Foot and Ankle Society (AOFAS) score, the Böhler angle (BA) for radiographic analysis, and noted any complications. We divided the patients into those managed with the Omoto technique (group O) and those managed without the Omoto technique (group N). Patients were matched by age, sex, and fracture type, resulting in 43 patients per group. The use of the Omoto technique at the time of injury significantly improved the Böhler angle (BA). Furthermore, there were no significant differences in AOFAS, postoperative complications, or BA values at the final follow-up. In conclusion, our study demonstrates that the Omoto technique, when used preoperatively for calcaneal fractures, does not negatively impact the outcomes of subsequent surgical treatments. For patients who prefer to avoid surgery, the Omoto technique can be an effective initial intervention. Additionally, our findings suggest that the Omoto technique may facilitate less invasive surgical options in certain cases.

DOI： 10.1053/j.jfas.2024.02.003

Risk factors of periprosthetic joint infection after hemiarthroplasty for displaced femoral neck fracture in the elderly: Analysis of 1619 cases in the multicenter database. International journal

Satoshi Sumi, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroaki Nakashima, Kenichi Mishima, Tetsuro Takatsu, Shiro Imagama

Injury Vol. 55 ( 7 ) page： 111603 - 111603 2024.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This multicenter retrospective study focuses on understanding the incidence, causative bacteria, and risk factors for Periprosthetic Joint Infection (PJI) following hemiarthroplasty in elderly patients with displaced femoral neck fractures (FNF). METHODS: From 2016 to 2020, 1,619 patients were diagnosed with displaced FNFs and treated surgically across 11 centers. After exclusions, 1,438 patients (399 men and 1,039 women) were included in the study, averaging 82.1 years in age and 20.2 kg/m² in BMI, observed over 25.7 months on average. Data on demographics, medical history, surgical details, and complications were described. RESULTS: PJI occurred in 20 of the 1438 patients (1.4%). The causative organism was methicillin-susceptible Staphylococcus aureus in 6 patients and methicillin-resistant S. aureus in 6 patients. In patients' backgrounds, the average age was slightly higher in the non-PJI group (82.1 years) compared to the PJI group (80.4 years). There was a higher percentage of males in the PJI group (45%) than in the non-PJI group (27.5%). Drug history showed that the prevalence of anticoagulant use in the PJI group was 25%. Peripheral vascular disease and diabetes mellitus were more prevalent in the PJI group. Most patients in both groups were independent in daily activities. The blood transfusion rate was significantly higher in the PJI group (50%) than in the non-PJI group (23.8%). Notably, the incidence of hematoma was higher in the PJI group (40%). CONCLUSION: This multicenter retrospective study demonstrates a low incidence (1.4%) of PJI in elderly patients undergoing hemiarthroplasty for FNF, primarily due to Staphylococcus aureus. Increased usage of antiplatelets and anticoagulants, as well as comorbidities related to atherosclerosis, like peripheral vascular disease and diabetes mellitus, were observed in patients with PJI. Additionally, these patients experienced higher rates of blood transfusion and postoperative hematomas, highlighting the need for careful management. It should be noted, however, that this finding is a conclusion limited by study design issues, including the retrospective design, small PJI sample size, and variability in treatment approaches.

DOI： 10.1016/j.injury.2024.111603

Preoperative Sarcopenia Severity and Clinical Outcomes after Total Hip Arthroplasty. Reviewed International journal Open Access

Shinya Tanaka, Azusa Kayamoto, Chiaki Terai, Shusuke Nojiri, Yuki Fugane, Tomohiro Mori, Motoki Nagaya, Masato Kako, Hiroki Iida, Yusuke Osawa, Yasuhiko Takegami, Yoshihiro Nishida

Nutrients Vol. 16 ( 13 ) 2024.7

Language：English Publishing type：Research paper (scientific journal)

The outcome of total hip arthroplasty (THA) in patients with end-stage arthritis of the hip is associated with preoperative physical status. This study was performed to examine the relationship between the preoperative severity of sarcopenia and clinical outcomes after THA. This retrospective cohort study was performed among 306 consecutive patients (mean age: 63.7 ± 12.9 years, 222 women) undergoing THA at a university hospital. The severity of sarcopenia was determined based on the skeletal muscle mass index (SMI), handgrip strength, and gait speed according to the criteria of the Asian Working Group for Sarcopenia 2019. The severe sarcopenia prevalence rate was 10.6%. Severe sarcopenia was significantly associated with the risk of delayed functional recovery (adjusted odds ratio, 2.82; 95% confidence interval, 1.03-7.72; p = 0.043) compared with the non-sarcopenia group after adjusting for pre-existing risk factors, including preoperative hip function and physical activity. The addition of SMI, handgrip strength, and gait speed to the model for risk of functional recovery delay significantly increased the area under the receiver operating characteristic curve (p = 0.038). Severe sarcopenia was significantly associated with poorer hip function and patient-reported outcomes at 6 months after surgery compared with the non-sarcopenia group. Severe sarcopenia was adversely associated with postoperative clinical outcomes in patients undergoing THA.

DOI： 10.3390/nu16132085

Descriptive analysis of incidence and risk factors for short intramedullary nail breakage in femoral intertrochanteric fractures: a multicenter (TRON group) retrospective study. Reviewed International journal

Hirokazu Noritake, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroaki Nakashima, Kenichi Mishima, Takanori Ito, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 34 ( 5 ) page： 2605 - 2611 2024.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The incidence of hip fractures is increasing. Femoral intertrochanteric fractures make up 50% of hip fractures and are treated by intramedullary nails. Implant breakage is a recognized complication that can have rare and serious implications. This study aimed to investigate implant breakage rates after surgical treatment for femoral intertrochanteric fractures. METHODS: This was a retrospective multicenter analysis. All 1854 patients who underwent surgical treatment for femoral intertrochanteric fractures were selected from 12 hospitals (TRON group) between 2016 and 2020. Exclusion criteria included implants other than those specified and follow-up periods less than three months. Demographic data, surgical details, and radiographic assessments were collected from medical records and X-ray evaluations. RESULTS: Among the 983 study patients, consisting of 245 males (24.9%) and 738 females (75.1%), the implant breakage rate was 0.31%, with three confirmed cases. The average age was 83.9 years. The mean follow-up period was 640.9 days. Two cases were linked to ASULOCK implants, and one to an OLSII implant. Statistical analysis showed a significantly higher incidence of ASULOCK implant breakage (p < 0.001). In the two cases of ASULOCK implant breakage and one case of OLSII implant breakage, breakage in all three implants occurred at the anti-rotation screws. CONCLUSIONS: There were no implant breakages of the main body of the implants; all breakages occurred in the additional anti-rotation screw. The necessity of the anti-rotation screw will require further discussion. These results can potentially inform clinical decisions and guide further research in preventing implant breakage.

DOI： 10.1007/s00590-024-03957-z

Association of mid-thigh quadriceps muscle quality with postoperative outcomes in patients with hip osteoarthritis undergoing total hip arthroplasty: a retrospective cohort study. Reviewed International journal

Hiroki Iida, Yasuhiko Takegami, Yusuke Osawa, Hiroto Funahashi, Yuto Ozawa, Hiroaki Ido, Takamune Asamoto, Keiji Otaka, Shinya Tanaka, Shiro Imagama

International orthopaedics Vol. 48 ( 7 ) page： 1715 - 1721 2024.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Muscle quality is more important than muscle mass for assessing physical function. Computed tomography (CT) is used to evaluate intramuscular fatty infiltration. The mid-thigh quadriceps CT attenuation values (CTV) expressed in Hounsfield units (HU) negatively correlate with physical function. Patients with hip osteoarthritis (HOA) have lower extremity muscle atrophy, including decreased cross-sectional area (CSA), CTV, and muscle strength. Using preoperative CT images, we investigated the association between mid-thigh quadriceps CSA, CTV, and postoperative outcomes in patients with HOA. METHODS: This study included 62 patients who had unilateral HOA (62 hips) and underwent total hip arthroplasty (THA). We investigated the association between preoperative and postoperative Japanese Orthopaedic Association (JOA) hip scores, 12-item Short Form survey (SF-12), mid-thigh quadriceps CSA, and CTV. RESULTS: The mean age was 64.7 ± 10.1 years, with 15 men (24.2%), and the mean body mass index was 24.3 ± 4.3 kg/m2. Secondary HOA was present in 79.0% of patients. The mean CSA and CTV of the mid-thigh quadriceps on the operative side were 38.8 ± 9.8 cm2 and 40.3 ± 7.8 HU, respectively. Multiple regression analyses adjusted for age and sex showed that preoperative mid-thigh quadriceps CSA was not associated with preoperative and postoperative JOA hip scores or SF-12. The preoperative mid-thigh quadriceps CTV was associated with the postoperative JOA hip score in the gait ability domain and SF-12 in the physical component summary domain. CONCLUSION: Preoperative muscle quality is associated with postoperative outcomes in patients who have HOA regardless of age and sex.

DOI： 10.1007/s00264-024-06142-3

Analysis of Calcaneal Avulsion Fractures Treated Surgically and Nonsurgically: A Retrospective Multicenter Study. Reviewed International journal Open Access

Yu Takahashi, Yasuhiko Takegami, Katsuhiro Tokutake, Yuta Asami, Hidetane Takahashi, Mihoko Kato, Tokumi Kanemura, Shiro Imagama

JB & JS open access Vol. 9 ( 3 ) 2024.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Calcaneal avulsion fractures (CAvFs) at the Achilles tendon insertion are among the more challenging fractures to treat. Although rare, they often require reoperation. The optimal treatment, including nonsurgical procedures and better implants for surgical procedures in the treatment of CAvFs, remains to be established. Therefore, our study aimed to (1) perform a descriptive evaluation of CAvFs, including cases managed nonsurgically, and (2) assess surgical procedures, including the incidence of complications and reoperation for surgically treated CAvFs. METHODS: In this multicenter retrospective study, we collected data of patients with CAvFs treated at 9 hospitals from 2012 to 2022. We performed a descriptive study of CAvFs and compared postoperative complications and reoperation rates for multiple surgical techniques and implants. The size of the bone fragments was quantified. RESULTS: The data of 70 patients with CAvFs were analyzed; 20 patients were treated nonsurgically, and 50 were treated surgically. The mean age of patients was 68.5 years; 67% of the patients were female. Nineteen percent of the patients had diabetes, and 19% had osteoporosis. The incidence of postoperative complications was 30%, with infection in 14%, necrosis in 26%, and loss of reduction in 18%. The reoperation rate was 22%. Surgical techniques with use of cannulated cancellous screws were performed in 80% of the surgical cases. Cannulated cancellous screw (CCS) fixation alone resulted in a reoperation rate of 35%, whereas additional augmentation, including washers with CCS fixation, resulted in a reoperation rate of 10%. CCS fixation was successfully performed, although suture anchors were used in some cases with smaller fragments. CONCLUSIONS: CAvFs occurred more frequently in older women and had a high rate of postoperative complications. A combination of CCS with augmentation was more effective at reducing postoperative complications than CCS fixation alone, even when the bone fragment size was small. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

DOI： 10.2106/JBJS.OA.23.00127

Retrospective study comparing the accuracies of handheld infrared stereo camera and augmented reality-based navigation systems for total hip arthroplasty. Reviewed International journal

Shinya Tanaka, Yasuhiko Takegami, Yusuke Osawa, Masanori Okamoto, Shiro Imagama

Archives of orthopaedic and trauma surgery Vol. 144 ( 6 ) page： 2811 - 2821 2024.6

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The use of portable navigation systems (PNS) in total hip arthroplasty (THA) has become increasingly prevalent, with second-generation PNS (sPNS) demonstrating superior accuracy in the lateral decubitus position compared to first-generation PNS. However, few studies have compared different types of sPNS. This study retrospectively compares the accuracy and clinical outcomes of two different types of sPNS instruments in patients undergoing THA. METHODS: A total of 158 eligible patients who underwent THA at a single institution between 2019 and 2022 were enrolled in the study, including 89 who used an accelerometer-based PNS with handheld infrared stereo cameras in the Naviswiss group (group N) and 69 who used an augmented reality (AR)-based PNS in the AR-Hip group (group A). Accuracy error, navigation error, clinical outcomes, and preparation time were compared between the two groups. RESULTS: Accuracy errors for Inclination were comparable between group N (3.5° ± 3.0°) and group A (3.5° ± 3.1°) (p = 0.92). Accuracy errors for anteversion were comparable between group N (4.1° ± 3.1°) and group A (4.5° ± 4.0°) (p = 0.57). The navigation errors for inclination (group N: 2.9° ± 2.7°, group A: 3.0° ± 3.2°) and anteversion (group N: 4.3° ± 3.5°, group A: 4.3° ± 4.1°) were comparable between the groups (p = 0.86 and 0.94, respectively). The preparation time was shorter in group A than in group N (p = 0.036). There were no significant differences in operative time (p = 0.255), intraoperative blood loss (p = 0.387), or complications (p = 0.248) between the two groups. CONCLUSION: An Accelerometer-based PNS using handheld infrared stereo cameras and AR-based PNS provide similar accuracy during THA in the lateral decubitus position, with a mean error of 3°-4° for both inclination and anteversion, though the AR-based PNS required a shorter preparation time.

DOI： 10.1007/s00402-024-05330-5

Is spinopelvic compensation associated with unstable gait?: Analysis using whole spine X-rays and a two-point accelerometer during gait in healthy adults. Reviewed International journal

Naoki Segi, Hiroaki Nakashima, Sadayuki Ito, Jun Ouchida, Azusa Kayamoto, Ryotaro Oishi, Ippei Yamauchi, Yasuhiko Takegami, Shinya Ishizuka, Taisuke Seki, Yukiharu Hasegawa, Shiro Imagama

Gait & posture Vol. 111 page： 22 - 29 2024.6

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Pelvic incidence (PI)-lumbar lordosis (LL) mismatch has a significant destabilizing effect on the center of gravity sway in the static standing position. However, the association between spinopelvic alignment and balance during gait in healthy volunteers is poorly understood. RESEARCH QUESTION: The degree of PI-LL mismatch and trunk anterior tilt in the static standing posture influences dynamic balance during gait. METHODS: In this study, 131 healthy volunteers were divided into two groups: harmonious group (PI - LL ≤ 10°; n = 91) and unharmonious group (PI - LL > 10°; n = 40). A two-point accelerometer system was used for gait analysis; accelerometers were attached to the pelvis and upper trunk to measure acceleration in the forward-backward, right-left, and vertical directions so that sagittal (front-back) deviation width, coronal (right-left) width, and vertical width and their ratios were calculated. Measurements were compared between the two groups, and correlations between alignment and accelerometer data were examined. RESULTS: The harmonious group showed a negative correlation between pelvic sagittal width and PI - LL, pelvic tilt (PT), and sagittal vertical axis (SVA) (correlation coefficient ρ = -0.42, -0.38, and -0.4, respectively), and a positive correlation between sagittal ratio and PI - LL (ρ = 0.35). The unharmonious group showed a positive correlation between pelvic sagittal width and PI and PT (ρ = 0.43 and 0.33, respectively) and between sagittal ratio and SVA (ρ = 0.32). The unharmonious group showed a positive correlation between upper trunk sagittal width and PI - LL and PT (ρ = 0.38 and 0.36, respectively). SIGNIFICANCE: The association between spinal alignment and gait parameters differs depending on the presence or absence of PI-LL mismatch. The degree of pelvic compensation and trunk anterior tilt during static standing were associated with unstable gait balance.

DOI： 10.1016/j.gaitpost.2024.04.013

Association between advanced glycation end-products and fall risk in older adults: The Yakumo Study. Reviewed

Hiroki Iida, Yasuhiko Takegami, Yusuke Osawa, Hiroto Funahashi, Yuto Ozawa, Hiroaki Ido, Takamune Asamoto, Keiji Otaka, Shinya Tanaka, Hiroaki Nakashima, Shinya Ishizuka, Taisuke Seki, Yukiharu Hasegawa, Shiro Imagama

Geriatrics & gerontology international Vol. 24 ( 6 ) page： 517 - 522 2024.6

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

AIM: Advanced glycation end-products (AGEs) are irreversibly and heterogeneously formed compounds during the non-enzymatic modification of macromolecules, such as proteins. Aging and lifestyle habits, such as high-fat and high-protein diets, and smoking, promote AGEs accumulation. This study aimed to investigate the relationship between fall risk and AGEs in community-dwelling older adults. METHODS: This cross-sectional study included patients from the 2022 Yakumo Study who were evaluated for fall risk index 5-items version, locomotive syndrome stage and AGEs. AGEs were evaluated using Skin autofluorescence (SAF) measured by the AGE reader (DiagnOptics Technologies BV, Groningen, the Netherlands). We divided the participants into two groups according to the presence or absence of fall risk (fall risk index 5-items version ≥6 or not), and investigated the factors associated with fall risk. RESULTS: The fall risk group had a higher age and SAF, and a higher proportion of locomotive syndrome stage >2 than the without fall risk group in patients aged ≥65 years (P < 0.01). The multivariate logistic regression analysis after adjustment of age, sex and body mass index showed that locomotive syndrome stage ≥2 and SAF were independent associators of fall risk in older adults (odds ratio 3.26, P < 0.01, odds ratio 2.96, P < 0.05, respectively). The optimal cutoff value of the SAF for fall risk was 2.4 (area under the curve 0.631; 95% CI 0.53-0.733; sensitivity 0.415; specificity 0.814; P < 0.05). CONCLUSION: The accumulation of AGEs in skin tissues can be used to screen for fall risk comprehensively. Geriatr Gerontol Int 2024; 24: 517-522.

DOI： 10.1111/ggi.14871

Comparison of conjoined tendon-preserving posterior approach and conventional posterolateral approach in hemiarthroplasty for femoral neck fracture in the elderly: A multicenter (TRON group) retrospective study. Reviewed

Keisuke Ogura, Yasuhiko Takegami, Yutaro Kuwahara, Katsuhiro Tokutake, Ryo Nakashima, Shigeto Yamamoto, Kenta Naito, Takehiro Kasai, Kazuya Makida, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2024.5

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Femoral neck fractures (FNF) are one of the most common traumatic injuries in the elderly. The conjoined tendon-preserving posterior (CPP) approach was developed as a modification of the conventional posterolateral (PL) approach in hemiarthroplasty (HA) for displaced femoral neck fractures (FNF) to reduce postoperative dislocation. We hypothesized that the CPP approach would result in fewer dislocations and similar functional and radiographic outcomes compared to the PL approach. PATIENTS AND METHODS: This was a retrospective multicenter (TRON group) study. We evaluated the rate of complications, and functional and radiographic outcomes for patients aged >65 years who underwent HA via the PL approach or the CPP approach from 2017 to 2019 and followed up for at least 24 months. To adjust for baseline differences between the groups, a propensity score-matching algorithm was used in a 1:1 ratio. RESULTS: We identified 135 patients who underwent HA via the PL approach and 135 patients via the CPP approach. The mean follow-up period was 32.4 ± 14.0 months. The incidence of dislocation was 6 in 135 patients (4.4%) in the PL group and 0 in 135 patients (0%) in the CPP group, and there was significant difference (p = 0.04). Operation time was equivalent between the two groups (73.1 ± 30.4 vs. 71.8 ± 30.0 min; p = 0.72). The rate of varus insertion of stems in the PL group lower than that in the CPP group (19.3% vs. 33.3%; p = 0.01). Postoperative Parker's mobility score was similar between the two groups at 12 months follow-up (6.17 vs. 6.27; p = 0.81). CONCLUSION: The CPP approach showed a significantly lower dislocation rate, similar functional outcome and more varus stem insertions compared with the PL approach in this retrospective study.

DOI： 10.1016/j.jos.2024.05.003

Relationship between locomotive syndrome and advanced glycation end products measured by skin autofluorescence in community-dwelling patients: the Yakumo Study. Reviewed

Yuto Ozawa, Yasuhiko Takegami, Taisuke Seki, Yusuke Osawa, Hiroki Iida, Masanori Okamoto, Hiroaki Nakashima, Shinya Ishizuka, Yukiharu Hasegawa, Shiro Imagama

Nagoya journal of medical science Vol. 86 ( 2 ) page： 314 - 325 2024.5

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Advanced glycation end products (AGEs) have been reported to be associated with osteoporosis, aging, sarcopenia, and frailty. This study aimed to investigate the association AGEs with locomotive syndrome (LS). Participants were Japanese individuals aged 39 years or older who participated in the Yakumo Study (n=230). AGEs were measured by skin autofluorescence (SAF) using an AGE reader. We investigated SAF values for each locomotive stage. Multivariate logistic regression models were used to calculate the odds ratios of LS-associated factors. The relationships between SAF and physical performance and bone mineral density (BMD) were investigated. A receiver operating characteristic (ROC) curves were generated to determine the optimal cut-off value of SAF for predicting LS. SAF values tended to increase correspondingly with LS severity. SAF was an independently explanatory factor for LS (odds ratio 2.70; 95% confidence interval [CI] 1.040-6.990). SAF was positively correlated with the 10-m walking speed, The Timed Up and Go test results, and was negatively correlated with BMD. ROC curve represented by SAF for the presence or absence of LS risk had an area under the curve of 0.648 (95% CI: 0.571-0.726). High SAF values were identified as an independent risk factor for LS. AGEs could be a potential screening tool for people for LS.

DOI： 10.18999/nagjms.86.2.314

Diaphyseal forearm fracture management in adolescent patients from 2011 to 2020: A multicenter study of surgery and regional anesthesia trends. Reviewed

Yoshihiko Kimura, Yuta Asami, Katsuhiro Tokutake, Yasuhiko Takegami, Kazuma Oshima, Noriko Ishihara, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2024.4

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Diaphyseal forearm fractures are common traumatic injuries among children. There has been much debate on the use of intramedullary nailing (IMN) or plate fixation in the adolescent population (10-16 years of age). Furthermore, as ultrasound technology has advanced, the safety and efficacy of ultrasound-guided axillary brachial plexus block for children has dramatically improved. Therefore, anesthesia options for adolescent patients have increased in recent years. This study aimed to investigate recent surgical and regional anesthesia trends of diaphyseal forearm fractures in patients 10 to 16 years of age in Japan through a multicenter epidemiological survey from 2011 to 2020. METHODS: This retrospective, multicenter study included 226 pediatric patients with diaphyseal forearm fracture aged 10-16 years treated from January 2011 to December 2020. We divided the patients into four groups according to the period in which they were treated: early (2011-2013), middle (2014-2016), late (2017-2019), and COVID-19 (2020). Information from medical records was used to investigate the number of surgeries, types of anesthesia administered, and internal fixation methods used for diaphyseal forearm fracture in adolescent patients during each period. RESULTS: The number of surgeries was generally constant in each period but decreased during the COVID-19 period. In the early, middle, late, and COVID-19 periods, the percentages of surgeries performed under regional anesthesia were 67.7, 85.5, 87.0, and 100% respectively (p = 0.003). During the same periods, the percentages of patients receiving IMN were 41.5, 49.3, 58.0, and 66.7%, respectively (p = 0.033). CONCLUSION: The use of IMN and regional anesthesia to treat diaphyseal forearm fracture in patients 10 to 16 years of age steadily increased during the study period from 2011 to 2020. These results indicate that regional anesthesia is safe, effective, and well-tolerated by adolescent patients. The treatment strategy for diaphyseal forearm fractures in adolescents using regional anesthesia in combination with IMN worked well and was effective during COVID-19. Our evidence suggests this trend will continue. We anticipate that our findings can be extrapolated for upper extremity fractures in adolescent patients beyond the Tokai region of Japan where the study was based.

DOI： 10.1016/j.jos.2024.03.009

Comparing short vs. intermediate and long nails in elderly patients with unstable multifragmental femoral trochanteric fractures (AO type A2): Multicenter (TRON group) retrospective study. Reviewed International journal

Hidetoshi Tsugeno, Yasuhiko Takegami, Katsuhiro Tokutake, Kenichi Mishima, Hiroaki Nakashima, Kazuyoshi Kobayashi, Shiro Imagama

Injury Vol. 55 ( 4 ) page： 111420 - 111420 2024.4

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Unstable femoral trochanteric fractures (FTFs), especially Arbeitsgemeinschaft für Osteosynthesefragen/ the Orthopedic Trauma Association (AO/OTA) 31-A2 fractures, which are multifragment fractures, occur in elderly individuals with osteoporosis and are associated with high mortality and complication rates due to prolonged immobilization. Longer nails (LNs) were developed to obtain superior fracture site stabilization in unstable FTFs. We hypothesized that the postoperative outcomes of elderly patients with unstable FTFs treated with LNs would be superior to those of patients treated with short nails (SNs), with fewer complications. METHODS: This multicenter retrospective study aimed to compare the outcomes of SNs versus LNs in elderly patients with unstable FTFs. From the Trauma Research Group of our university (TRON) database, 1854 trochanteric fractures treated between January 2016 and December 2020 were extracted. A total of 174 patients>65 years of age with AO/OTA 31-A2 fractures were included in the present study. They were divided into the SN group and the LN group and matched for age and sex. Parameters such as operative time, blood loss, survival rate, Parker Mobility Score (PMS), and numerical rating scale (NRS) for pain, complications, and radiographic findings were analyzed. RESULTS: Both groups included 67 patients with an average age of 87.32 years. The LN group had a longer operative time (76.52 min vs. 51.61 min, P < 0.001) and more blood loss (106.79 mL vs. 49.98 mL, P = 0.014) in comparison to the SN group. However, the 1-year survival rate, PMS, and NRS for pain did not differ to a statistically significant extent between the groups. The rates of complications, including screw cutout, nonunion, implant breakage, osteonecrosis of the femoral head, and surgical site infections, were comparable. The radiographic findings, including the nail/canal ratio, progression of varus, and sliding distance, were also similar. CONCLUSION: Although LNs are associated with longer operative times and increased blood loss, the overall outcomes and complication rates are comparable to those of SNs in elderly patients with AO/OTA 31-A2 type unstable FTFs. The use of LNs did not confer any distinct advantages for this specific type of fracture.

DOI： 10.1016/j.injury.2024.111420

Anti-sclerostin antibody therapy prevents post-ischemic osteonecrosis bone collapse via interleukin-6 association. Reviewed International journal

Yuto Ozawa, Yasuhiko Takegami, Yusuke Osawa, Takamune Asamoto, Shinya Tanaka, Shiro Imagama

Bone Vol. 181 page： 117030 - 117030 2024.4

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Osteonecrosis of the femoral head (ONFH) is a debilitating condition characterized by subchondral bone necrosis, which frequently culminates in joint destruction. Although total hip arthroplasty is conventionally practiced to remediate ONFH, for patients under the age of 60, the outcomes can be suboptimal. Chronic inflammation, particularly that mediated by interleukin-6 (IL-6), has been conjectured to be a potential mechanism underlying the etiology of ONFH. This study aimed at exploring the interplay between IL-6, the canonical Wnt signaling pathway, and ONFH to provide insights for potential therapeutic interventions. Human ONFH specimens depicted an elevation in β-catenin expression in the transitional layer, while IL-6 levels were pronounced in the same region. Subsequently, mouse models of ischemic osteonecrosis were treated with an anti-sclerostin antibody to assess its effects on bone metabolism and cellular processes. Histological analysis revealed that the administration of anti-sclerostin antibodies effectuated early recovery from bone necrosis, reduced empty lacunae, and suppressed IL-6 expression. The treatment evidently initiated the activation of the Wnt/β-catenin signaling pathway, presenting a potential mechanism associated with IL-6-mediated inflammation. Furthermore, the antibody upregulated osteoblast formation, downregulated osteoclast formation, and increased bone volume. Micro-CT imaging demonstrated increased bone volume, prevented epiphyseal deformity, and improved compression strength. Therefore, this study yields significant findings, indicating the potency of anti-sclerostin antibodies in effectively modulating the Wnt/β-catenin pathway, associating with IL-6 expression, and preventing post-ONFH bone collapse. Additionally, this preclinical investigation in mouse models offers an avenue for prospective research on potential therapeutic interventions against human ONFH.

DOI： 10.1016/j.bone.2024.117030

Obesity Is Associated with Asymptomatic Vertebral Fractures: A Yakumo Study. Reviewed International journal Open Access

Yuichi Miyairi, Hiroaki Nakashima, Sadayuki Ito, Naoki Segi, Jun Ouchida, Ryotaro Oishi, Ippei Yamauchi, Masaaki Machino, Taisuke Seki, Shinya Ishizuka, Yasuhiko Takegami, Yukiharu Hasegawa, Shiro Imagama

Journal of clinical medicine Vol. 13 ( 7 ) 2024.4

Language：English Publishing type：Research paper (scientific journal)

(1) Background: Patients with primary vertebral fracture (VF) are at high risk of re-fracture and mortality. However, approximately two-thirds of patients with VFs receive minimal clinical attention. (2) Methods: The current study aimed to investigate the factors associated with asymptomatic VFs in middle-aged and elderly individuals who underwent resident health examinations. (3) Results: The current study included 217 participants aged > 50 years. VFs were diagnosed based on lateral radiographic images using Genant's semiquantitative (SQ) method. The participants were divided into non-VF (N; SQ grade 0) and asymptomatic VF (F; SQ grades 1-3) groups. Data on body composition, blood tests, quality of life measures, and radiographic parameters were assessed. A total of 195 participants were included in the N group (mean age, 64.8 ± 7.8 years), and 22 were in the F group (mean age, 66.1 ± 7.9 years). The F group had a significantly higher body mass index (BMI), body fat percentage (BF%), and proportion of patients with knee osteoarthritis (KOA) than the N group. The F group had a significantly higher knee joint pain visual analog scale (VAS) score and painDETECT score than the N group. Logistic regression analysis showed that BF% was associated with asymptomatic VFs. (4) Conclusions: Middle-aged and elderly individuals with asymptomatic VF presented with high BMIs, BF%, and incidence of KOA.

DOI： 10.3390/jcm13072063

Does Early and Late Weight Bearing Have an Effect on the Results of Elderly Tibial Plateau Fractures with Internal Fixation?: A Multicenter (TRON Group) Study. Reviewed International journal

Yoshito Sudo, Yasuhiko Takegami, Katsuhiro Tokutake, Keita Shimizu, Keita Naruse, Tetsuro Takatsu, Shiro Imagama

Indian journal of orthopaedics Vol. 58 ( 4 ) page： 354 - 361 2024.4

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: There is still no consensus on the length of the non-bearing period required for tibial plateau fractures (TPFs) treated surgically. Several studies showed that full weight bearing immediately postoperatively does not affect fixation or cause joint collapse in patients with TPF. While there are concerns about weight bearing in the elderly due to fragile bone quality, their physical disability often makes it difficult to carry out activities of daily life when weight bearing is not allowed. The purpose of this study was to assess differences in clinical and radiographic outcomes between an early weight-bearing (EWB) group and a non-weight-bearing (NWB) group following TPF in elderly patients. MATERIAL AND METHODS: We extracted the data of 432 patients who suffered TPF from January 2011 to December 2020 from a database which is named TRON. We excluded patients with insufficient follow-up postoperatively, AO type A/C fracture, age < 60 years old, multiple trauma, and those lost to follow-up. Finally, 91 patients were eligible. EWB group patients were encouraged to perform partial weight-bearing walking at ≤ 4 weeks after surgery, whereas NWB group patients were not allowed weight bearing for > 4 weeks after surgery. Baseline intergroup differences were adjusted for by matching age, sex, body mass index, smoking history, and injury mechanism. We compared Knee Society Score (KSS), timing of full weight bearing, and X-ray findings including step-off, tibia plateau angle, plateau slope, and condylar widening in the X-rays between the two groups. RESULTS: There were no significant statistical differences between the EWB group and NWB group after matching. The mean follow-up period was 28.0 (range 12-73) months. All cases did not require reoperation or additional procedures. The median KSS at 12 months or at the last follow up postoperatively was 100 (77-100) vs. 95 (75-100) points (P = 0.33). There were no differences in fracture-related infection rates or wound dehiscence. In the radiological evaluation of EWB and NWB, the correction loss of condylar widening was only significantly greater for EWB compared to NWB. CONCLUSIONS: We found that early weight bearing could contribute to increased condylar widening. While our short-term follow-up didn't reveal any significant clinical differences, this highlights the need for long-term follow-up to comprehensively understand the implications of these radiographic changes.

DOI： 10.1007/s43465-024-01113-7

視力が静的・動的体幹バランスに及ぼす影響(体幹2点歩行動揺計The Walkingを用いた検討) Yakumo Study

伊藤定之, 中島宏彰, 世木直喜, 大内田隼, 石塚真哉, 竹上靖彦, 大石遼太郎, 山内一平, 宮入祐一, 森田圭則, 松本太郎, 長谷川幸治, 今釜史郎

Journal of Spine Research Vol. 15 ( 3 ) page： 297 - 297 2024.4

中高年者における脊柱アライメントと歩行時体幹動揺の関係 2点加速度センサによる歩行解析結果

世木直喜, 中島宏彰, 伊藤定之, 大内田隼, 栢本あずさ, 大石遼太郎, 宮入祐一, 山内一平, 森田佳則, 関泰輔, 竹上靖彦, 石塚真哉, 長谷川幸治, 今釜史郎

Journal of Spine Research Vol. 15 ( 3 ) page： 197 - 197 2024.4

Fracture of the patella involving inferior pole is associated with postoperative patella baja - A retrospective multicenter study. Reviewed

Fuminori Murase, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroki Oyama, Oki Arakawa, Tetsuro Takatsu, Hiroaki Nakashima, Kenichi Mishima, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2024.3

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: The patella fracture involving of inferior pole fractures (IPF) may be associated with patella baja, However, the clinical impact of this condition remains unclear. This study aims to clarify 1) the incidence of patella baja following patellar fracture surgery, 2) the associated clinical outcomes with and without the presence of patella baja, and 3) the potential correlation between the detection of IPF on CT and the occurrence of patella baja. METHODS: We conducted a retrospective multicenter study involving 251 patients who underwent surgical treatment for patellar fractures. Patients were divided into the patella baja (PB; n = 49) group and patella norma (PN; n = 202) group. Data collected included demographics, radiographic findings, surgical details, and postoperative complications. We compared these items between PB group and PN group. Logistic regression analyses were used to identify risk factors for patella baja. RESULTS: Immediately following surgery, 36 (14.3%) patients presented with patella baja which increased to 49 cases (19.5%) at six months postoperatively. There is no statistically significant difference in the demographics, surgical details, clinical outcomes and complication between PB group and PN group. While, in the radiographical assessment, the prevalence of IPF on CT scan in the patella baja group was significantly higher than that in the patella norma group. By logistic regression analysis, IPFP on CT was identified as an independent risk factor for patella baja. (odds ratio 2.11, 95% confidence interval: 1.03-4.33, p = 0.042). CONCLUSION: In patients with patellar fractures, the incidence of patella baja increased from 14.3% immediately post-surgery to 19.5% at the six-month check-up. No significant differences were observed in clinical outcomes between the patella baja group and the norma group. The patella fracture involving IPF on CT emerged as a predictive factor for patella baja.

DOI： 10.1016/j.jos.2024.03.008

External validation of a deep learning model for predicting bone mineral density on chest radiographs. Reviewed International journal

Takamune Asamoto, Yasuhiko Takegami, Yoichi Sato, Shunsuke Takahara, Norio Yamamoto, Naoya Inagaki, Satoshi Maki, Mitsuru Saito, Shiro Imagama

Archives of osteoporosis Vol. 19 ( 1 ) page： 15 - 15 2024.3

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

UNLABELLED: We developed a new model for predicting bone mineral density on chest radiographs and externally validated it using images captured at facilities other than the development environment. The model performed well and showed potential for clinical use. PURPOSE: In this study, we performed external validation (EV) of a developed deep learning model for predicting bone mineral density (BMD) of femoral neck on chest radiographs to verify the usefulness of this model in clinical practice. METHODS: This study included patients who visited any of the collaborating facilities from 2010 to 2020 and underwent chest radiography and dual-energy X-ray absorptiometry (DXA) at the femoral neck in the year before and after their visit. A total of 50,114 chest radiographs were obtained, and BMD was measured using DXA. We developed the model with 47,150 images from 17 facilities and performed EV with 2914 images from three other facilities (EV dataset). We trained the deep learning model via ensemble learning based on chest radiographs, age, and sex to predict BMD using regression. The outcomes were the correlation of the predicted BMD and measured BMD with diagnoses of osteoporosis and osteopenia using the T-score estimated from the predicted BMD. RESULTS: The mean BMD was 0.64±0.14 g/cm2 in the EV dataset. The BMD predicted by the model averaged 0.61±0.08 g/cm2, with a correlation coefficient of 0.68 (p<0.01) when compared with the BMD measured using DXA. The accuracy, sensitivity, and specificity of the model were 79.0%, 96.6%, and 34.1% for T-score < -1 and 79.7%, 77.1%, and 80.4% for T-score ≤ -2.5, respectively. CONCLUSION: Our model, which was externally validated using data obtained at facilities other than the development environment, predicted BMD of femoral neck on chest radiographs. The model performed well and showed potential for clinical use.

DOI： 10.1007/s11657-024-01372-9

Long-term oral meclozine administration improves survival rate and spinal canal stenosis during postnatal growth in a mouse model of achondroplasia in both sexes. Reviewed International journal

Hiroto Funahashi, Masaki Matsushita, Ryusaku Esaki, Kenichi Mishima, Bisei Ohkawara, Yasunari Kamiya, Yasuhiko Takegami, Kinji Ohno, Hiroshi Kitoh, Shiro Imagama

JBMR plus Vol. 8 ( 4 ) page： ziae018 2024.3

Language：English Publishing type：Research paper (scientific journal)

Achondroplasia (ACH) is a skeletal dysplasia characterized by short-limbed short stature caused by the gain-of-function mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. Activated FGFR3, which is a negative regulator of bone elongation, impairs the growth of long bones and the spinal arch by inhibiting chondrocyte proliferation and differentiation. Most patients with ACH have spinal canal stenosis in addition to short stature. Meclozine has been found to inhibit FGFR3 via drug repurposing. A 10-d treatment with meclozine promoted long-bone growth in a mouse model of ACH (Fgfr3ach mice). This study aimed to evaluate the effects of long-term meclozine administration on promoting bone growth and the spinal canal in Fgfr3ach mice. Meclozine (2 mg/kg/d) was orally administered to Fgfr3ach mice for 5 d per wk from the age of 7 d to 56 d. Meclozine (2 mg/kg/d) significantly reduced the rate of death or paralysis and improved the length of the body, cranium, and long bones in male and female Fgfr3ach mice. Micro-computed tomography analysis revealed that meclozine ameliorated kyphotic deformities and trabecular parameters, including BMD, bone volume/tissue volume, trabecular thickness, and trabecular number at distal femur of Fgfr3ach mice in both sexes. Histological analyses revealed that the hypertrophic zone in the growth plate was restored in Fgfr3ach mice following meclozine treatment, suggesting upregulation of endochondral ossification. Skeletal preparations demonstrated that meclozine restored the spinal canal diameter in Fgfr3ach mice in addition to improving the length of each bone. The 2 mg/kg/d dose of meclozine reduced the rate of spinal paralysis caused by spinal canal stenosis, maintained the growth plate structure, and recovered the bone quality and growth of axial and appendicular skeletons of Fgfr3ach mice in both sexes. Long-term meclozine administration has the potential to ameliorate spinal paralysis and bone growth in patients with ACH.

DOI： 10.1093/jbmrpl/ziae018

A large preoperative pelvic oblique angle affects perception of leg length discrepancy after total hip arthroplasty. Reviewed

Genta Takemoto, Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Daisaku Kato, Masanori Okamoto, Hiroki Iida, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 2 ) page： 566 - 573 2024.3

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: In some cases, patients feel a perceived leg length discrepancy (P-LLD) despite no radiographic leg length discrepancy (R-LLD) after total hip arthroplasty (THA). We aimed to investigate the rate of postoperative P-LLD and the factors that cause postoperative P-LLD. METHODS: A retrospective study was conducted on 100 patients with R-LLD ≤5 mm after THA. Patients were classified into two groups based on P-LLD post-THA: group P (with P-LLD) and group E (without P-LLD). Relevant data on the general characteristics and radiological findings between the two groups were compared. RESULTS: We observed that 25 & 75% of patients belonged to group P and group E, respectively, with no significant difference in patient background. Postoperative Japanese Orthopedic Association (JOA) classification of pain and activities of daily living scores were significantly lower in group P than in group E (37.2 ± 3.9 vs. 39.1 ± 2.2, respectively; P = 0.013, and 16.2 ± 4.2 vs. 18.2 ± 2.2, respectively; P = 0.011). The preoperative pelvic oblique angle (POA) was significantly larger in group P than in group E (3.3 ± 2.3° vs. -0.2 ± 2.1°; respectively; P < 0.01). The pelvis tilted toward the surgical side was significantly higher in group P than in group E(88% vs 57%; respectively; P = 0.013). The preoperative C7 coronal vertical axis (C7 CVA) was significantly larger in group P than in group E (6.7 ± 14.7 mm vs. -0.2 ± 10.3 mm; respectively; P = 0.028). Multivariate logistic analysis revealed that preoperative POA (OR, 3.71; 95% CI: 1.86-8.12; P < 0.01) and the pelvis tilted toward the surgical side (OR, 4.14; 95% CI: 2.07-9.71; P = 0.022) were independent risk factors for P-LLD after THA. CONCLUSION: Even though there was no postoperative R-LLD, 25% of patients had P-LLD. A large preoperative POA and the pelvis tilted toward the surgical side were independent risk factors for P-LLD after THA.

DOI： 10.1016/j.jos.2023.01.013

Effect of anaesthesia on cemented hemiarthroplasty -A multicentre retrospective study (TRON study). Reviewed

Shigeto Yamamoto, Yasuhiko Takegami, Katsuhiro Tokutake, Ryo Nakashima, Kenta Naito, Keisuke Ogura, Daizo Kato, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 2 ) page： 585 - 588 2024.3

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: This study aimed to investigate the survival rate, postoperative complications, and walking ability in cemented hemiarthroplasty (HA) for displaced femoral neck fractures according to the anaesthesia method. METHODS: We conducted a retrospective study of a multicentre group (the TRON group). Three hundred fifty-eight patients who underwent cemented HA between 2015 and 2019 were selected; 289 patients of ≥75 years of age with no missing data were included. Patient background factors were matched and patients were assigned to spinal anaesthesia (SA) and general anaesthesia (GA) groups. The primary outcome was death at any time during the follow-up period. Secondary outcomes included postoperative complications and walking ability assessed using the Parker mobility score (PMS). Overall survival was evaluated using the Kaplan-Meier method, and differences were compared using the log-rank test. The incidence of each complication and PMS were compared between the two groups using Fisher's exact test. RESULTS: Overall survival during follow-up was significantly higher in the SA group in comparison to the GA group (p = 0.037). In the SA and GA groups, the survival rate at 3 months postoperatively was 98.4% and 95.5%, respectively. The incidence of postoperative pneumonia was significantly higher in the GA (p = 0.012), and PMS at 3 months postoperatively was significantly higher in the SA group (p = 0.016). CONCLUSION: The survival rate of elderly patients who underwent cemented HA was better in the SA group. General anaesthesia in cemented HA may be associated with lower life expectancy, increased incidence of pneumonia, and decreased walking ability.

DOI： 10.1016/j.jos.2023.02.005

Comparison of the Outcomes of Plating, Screw Fixation, and Pinning in Sanders Type II Fractures: A Multicenter (TRON) Retrospective Study. Reviewed International journal

Mihoko Kato, Yasuhiko Takegami, Katsuhiro Tokutake, Yuta Asami, Yu Takahashi, Hidetane Takahashi, Hiroaki Kumagai, Shiro Imagama

The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons Vol. 63 ( 2 ) page： 171 - 175 2024.3

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Calcaneus fractures Sanders type II have been historically treated with various modalities. However, few studies compared these procedures directly. The multicenter (TRON group) retrospective study compared the radiographic and clinical outcomes of operative procedures using Kirschner wires (K-wires), cannulated cancellous screws (CCSs) and plates. Between 2014 and 2020, 121 patients with Sanders type II calcaneus fractures were surgically treated in our group using K-wire (Group K: n = 31), CCS (Group C: n = 60) or plate (Group p: n = 30) fixation. We assessed the American Orthopedic Foot and Ankle Society (AOFAS) score and infection after operation as clinical outcomes and Böhler's and Preiss' angles as radiographic outcomes. The AOFAS scores of the 3 groups showed a significant difference, with Group P showing significantly inferior scores to Group C at 6 months postoperatively and at the final follow-up examination (p = .015 and p < .001, respectively). The rate of infection did not differ to a statistically significant extent, but the incidence in Group P tended to be higher in comparison to the other groups. Among the three groups, Böhler's angle did not differ to a statistically significant extent immediately after the operation (p = .113) or at the final follow-up examination (p = .383). Postoperatively, Preiss' angle did not differ to a statistically significant extent (p = .251) but was significantly smaller in the Group C at the final follow-up examination (p = .0331). In Sanders type II calcaneus fracture, CCS fixation may obtain the best functional outcomes.

DOI： 10.1053/j.jfas.2023.10.002

A Longitudinal Study on the Effect of Exercise Habits on Locomotive Syndrome and Quality of Life during the Coronavirus Disease 2019 Pandemic. Reviewed International journal Open Access

Sadayuki Ito, Hiroaki Nakashima, Naoki Segi, Jun Ouchida, Ryotaro Oishi, Ippei Yamauchi, Shinya Ishizuka, Yasuhiko Takegami, Taisuke Seki, Yukiharu Hasegawa, Shiro Imagama

Journal of clinical medicine Vol. 13 ( 5 ) 2024.3

Language：English Publishing type：Research paper (scientific journal)

During the COVID-19 pandemic, this study investigated the potential of exercise habits to improve quality of life (QOL) and prevent locomotive syndrome (LS) in residents of Yakumo-cho, Hokkaido, Japan. Participants from the 2018 health checkup were surveyed in February 2022, focusing on 200 respondents. These individuals were divided based on their 2018 exercise habits (at least 1 h per week): the exercise group (E group) and the non-exercise group (N group), further categorized in 2022 into the 2022E and 2022N groups. QOL was measured using the SF-36 (physical functioning, general health, physical role, physical pain, vitality, social functioning, emotional role, and mental health) and EuroQoL 5-dimension 5-level questionnaires (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), and LS was assessed with the 25-question geriatric locomotive function scale. These showed no significant change in exercise habits from 2018 to 2022. In the non-LS group, the 2022E group had higher vitality and emotional role functioning scores compared to the 2022N group. For those with LS, the 2022E group reported less physical pain. Notably, the LS incidence was significantly lower in the 2022E group. This study concludes that consistent exercise habits positively impact QOL and reduce the LS risk, underscoring the importance of regular physical activity, especially during challenging times like a pandemic. These findings highlight the broader benefits of maintaining exercise routines for public health, particularly in periods of global health crises. Based on our findings, we recommend that people continue to exercise at least one hour per week to prevent LS.

DOI： 10.3390/jcm13051385

新型コロナウイルス感染症流行期間の生活様式および心身の変化とフレイルの関連 Reviewed

中江雅弥, 山田宏哉, 坪井良樹, 藤井亮輔, 奥深山寛, 渡邊真巳, 竹上靖彦, 石塚真哉, 中島宏彰, 今釜史郎, 鈴木康司

日本衛生学雑誌 Vol. 79 ( Suppl. ) page： S208 - S208 2024.3

高齢者上腕骨骨幹部骨折に対する治療方法が生命予後に与える影響手術治療と保存治療の比較 Reviewed

佐藤健, 竹上靖彦, 徳武克浩, 島本祐哉, 上野浩輝, 安藤智洋, 今釜史郎

日本整形外科学会雑誌 Vol. 98 ( 2 ) page： S224 - S224 2024.3

高齢者上腕骨骨幹部骨折の生命予後とその危険因子について多施設共同後方視的研究(TRON study) Reviewed

佐藤健, 竹上靖彦, 徳武克浩, 島本祐哉, 上野浩輝, 安藤智洋, 今釜史郎

日本整形外科学会雑誌 Vol. 98 ( 2 ) page： S224 - S224 2024.3

Cellular senescence is associated with osteonecrosis of the femoral head while mesenchymal stem cell conditioned medium inhibits bone collapse. Reviewed International journal Open Access

Masanori Okamoto, Hiroaki Nakashima, Kiyoshi Sakai, Yasuhiko Takegami, Yusuke Osawa, Junna Watanabe, Sadayuki Ito, Hideharu Hibi, Shiro Imagama

Scientific reports Vol. 14 ( 1 ) page： 3329 - 3329 2024.2

Language：English Publishing type：Research paper (scientific journal)

Osteonecrosis of the femoral head (ONFH) is a type of ischemic osteonecrosis that causes pain, loss of function, and femoral head collapse. Here, we analyzed samples of femoral heads excised from patients with ONFH to clarify the relationship between ischemic osteonecrosis and cellular senescence. X-gal staining was strong and p16INK4a-positive cells were abundant in the transitional region of ONFH. The β-galactosidase-positive cells in the transitional region were also positive for nestin, periostin, or DMP-1. In contrast, no β-galactosidase-positive cells were detected in the healthy region. The senescence-associated p16INK4a, p21, and p53 were upregulated in ONFH tissue. We also examined and analyzed a mouse ischemic femoral osteonecrosis model in vivo to verify the association between ONFH and cellular senescence. Human mesenchymal stem cell-conditioned medium (MSC-CM) was administered to determine its therapeutic efficacy against cellular senescence and bone collapse. MSC-CM reduced the number of senescent cells and downregulated the aforementioned senescence-related genes. It also decreased the number of empty lacunae 4 weeks after ischemia induction and promoted bone formation. At 6 weeks post-surgery, MSC-CM increased the trabecular bone volume, thereby suppressing bone collapse. We conclude that cellular senescence is associated with ONFH and that MSC-CM suppresses bone collapse in this disorder.

DOI： 10.1038/s41598-024-53400-w

Extension of the Antero-Posterior Necrotic Regions Associated With Collapse Cessation in Osteonecrosis of the Femoral Head. Reviewed International journal

Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Masanori Okamoto, Hiroki Iida, Shiro Imagama

The Journal of arthroplasty Vol. 39 ( 2 ) page： 387 - 392 2024.2

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Collapse cessation is of utmost importance following a long period of collapse due to osteonecrosis of the femoral head (ONFH). This study investigated the relationship between collapse cessation and the extent of the necrotic regions of ONFH. METHODS: Overall, 74 patients who had symptomatic ONFH (collapse < 3 mm) at the first visit with a minimum follow-up of 3 years were included in this study. Patients were categorized based on collapse progression or cessation into the progression and stable groups. The extent of the antero-posterior (AP) and medio-lateral necrotic regions between the groups was assessed using sagittal and coronal sections of T1-magnetic resonance imaging. Additionally, the most effective cutoff value was determined from the receiving operating characteristic curve where collapse cessation could be obtained, while the survival rates were determined with collapse progression as the endpoints were evaluated. RESULTS: Overall, 45 and 29 patients were in the progression and stable groups, respectively. The AP and medio-lateral necrotic regions were significantly different (P < .01 and P < .01, respectively) between the progression and stable groups. A cutoff value of 62.1% of the AP necrotic regions was determined from the receiving operating characteristic curve analysis. The 5-year survival rates with collapse progression as the endpoints were 5.4 and 77.8% in the AP necrotic regions of ≥62.1 and <62.1%, respectively (P < .01). CONCLUSIONS: Cases with AP necrotic regions of ≤62.1% can be expected to have collapse cessation, which could be a useful index for ONFH treatment strategies. LEVEL OF EVIDENCE: Level IV.

DOI： 10.1016/j.arth.2023.08.020

Early versus delayed weight bearing after internal fixation for femoral neck fracture in younger adults: A multicenter retrospective study. Reviewed International journal

Kanta Hasegawa, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroaki Nakashima, Kenichi Mishima, Kazuyoshi Kobayashi, Shiro Imagama

Injury Vol. 55 ( 2 ) page： 111292 - 111292 2024.2

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: Femoral neck fracture (FNF) is among the most common and devastating injuries that orthopedic surgeons encounter. However, the incidence of FNF is lower in younger adults than in elderly individuals. In elderly FNF patients, early weight bearing (EWB) is preferred to prevent loss of function and decreased activity. In younger adults, some surgeons decide on delayed-weight bearing (DWB) after surgery because EWB may cause femoral neck shortening. We aimed to compare the postoperative results (clinical outcome, radiological evaluation, and complications) of EWB and DWB after FNF surgery in younger adults. METHODS: The study included 151 younger adults (age: ≤65 years at injury; nondisplaced, n = 100; displaced, n = 51) who underwent internal fixation at 11 university-affiliated hospitals in 2016-2020, and who were followed for ≥1 year. Patients were divided into the EWB (EWB in early postoperative period) and DWB (beginning weight bearing at 4 weeks after surgery) groups. The two groups were matched for age, and nondisplaced (EWB and DWB, both n = 24) and displaced (EWB and DWB, both n = 11) FNF were analyzed. The study items were age, sex, body mass index (BMI), Charlson Comorbidity Index (CCI), presence of diabetes, days waiting for surgery, fracture type, Parker mobility score (PMS) at last follow-up examination, pain (Numerical Rating Scale: NRS), radiological evaluation (femoral neck shortening, Canulated Cancellous screws (CCS) backout, and complications (nonunion, femoral head osteonecrosis). RESULTS: The patient backgrounds of the nondisplaced and displaced types did not differ. The PMS was significantly higher in the DWB group at the last follow-up examination (nondisplaced: 8.00±2.20 vs. 6.67±2.22, p = 0.005, displaced: 8.67±0.89 vs. 6.91±2.77, p<0.001). NRS and the amount of femoral neck shortening were significantly lower in the DWB group (nondisplaced: 1.65±0.70 mm vs. 3.94±3.03 mm, p<0.001, displaced: 4.26± 2.64 mm vs. 8.91±5.69 mm, p<0.001). CCS backout did not differ between the groups. One case of each of nonunion and femoral head osteonecrosis were observed in the displaced EWB and DWB groups; these differences were not significant. CONCLUSIONS: DWB after internal fixation for FNF in younger adults was associated with better outcomes than EWB.

DOI： 10.1016/j.injury.2023.111292

Do Postural and Walking Stabilities Change over a Decade by Aging? A Longitudinal Study. Reviewed International journal Open Access

Naoki Segi, Hiroaki Nakashima, Sadayuki Ito, Jun Ouchida, Ryotaro Oishi, Ippei Yamauchi, Yuichi Miyairi, Yoshinori Morita, Yasuhiko Takegami, Shinya Ishizuka, Taisuke Seki, Yukiharu Hasegawa, Shiro Imagama

Journal of clinical medicine Vol. 13 ( 4 ) 2024.2

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Previous studies have demonstrated that the center of gravity (COG) is more unstable in the elderly than in young people. However, it is unclear whether aging itself destabilizes the COG. This study aimed to investigate changes in COG sway and gait kinematics over time by a longitudinal study of middle-aged and elderly adults. METHODS: This study included 198 healthy middle-aged and elderly people who underwent stabilometry at ten-year intervals. The participants' mean age at baseline was 62.9 ± 6.5 years, and 77 (39%) of them were male. The results of stabilometry (mean velocity, sway area, postural sway center in the medial-lateral direction [X center], and postural sway center in the anterior-posterior direction [Y center]), and results of exercise tests (the height-adjusted maximum stride length [HMSL] and the 10 m walk test [10MWT]) were analyzed. The destabilized group with 11 participants, whose mean velocity exceeded 3 cm/s after 10 years, was compared with the stable group with 187 participants, whose mean velocity did not exceed 3 cm/s. RESULTS: Mean velocity increased significantly over ten years (open-eye, from 1.53 ± 0.42 cm to 1.86 ± 0.67 cm, p < 0.001); however, the sway area did not change significantly. X center showed no significant change, whereas Y center showed a significant negative shift (open-eye, from -1.03 ± 1.28 cm to -1.60 ± 1.56 cm, p < 0.001). Although the results of 10MWT and initial HMSL did not differ significantly, the HMSL in the destabilized group at ten years was 0.64, which was significantly smaller than the 0.72 of others (p = 0.019). CONCLUSIONS: The ten-year changes in COG sway in middle-aged and elderly adults were characterized by a significant increase in mean velocity but no significant difference in sway area. Because the destabilized group had significantly smaller HMSL at ten years, instability at the onset of movement is likely to be affected by COG instability.

DOI： 10.3390/jcm13041081

Association between locomotive syndrome and fall risk in the elderly individuals in Japan: The Yakumo study. Reviewed

Hiroki Iida, Taisuke Seki, Yasuhiko Takegami, Yusuke Osawa, Daisaku Kato, Genta Takemoto, Kei Ando, Shinya Ishizuka, Yukiharu Hasegawa, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 1 ) page： 327 - 333 2024.1

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Patients with locomotive syndrome (LS) are poor ambulatory status and a high risk of requiring nursing care. The purpose of this study is to investigate the relationship between LS and fall risk among community-dwelling elderly individuals. METHODS: The subjects were Japanese elderly individuals aged 65 and over who participated in Yakumo study 2019 (N = 189). We defined the fall risk index 5 items version (FRI-5) ≥6 points as the fall risk group. LS was evaluated by stand-up test, two-step test, and 25-Geriatric Locomotive Function Scale (GLFS-25). We divided the subjects into two groups according to the presence or absence of fall risk, and investigated factors associated with fall risk. RESULTS: The fall risk group (30 patients, 15.9%) had higher GLSF-25 (P = 0.001). The results of logistic regression analysis adjusted for age, sex, BMI, and knee osteoarthritis revealed that GLFS-25 (OR: 1.052; 95%CI: 1.009-1.097) was independent factor associated with fall risk. In the ROC analysis, the optimal cut-off value of the GLFS-25 to predict fall risk was 12, which is equivalent to LS stage 1 (AUC 0.688; 95% CI: 0.588-0.787; sensitivity: 0.467, specificity: 0.836). CONCLUSIONS: GLFS-25 was associated with fall risk among community-dwelling elderly individuals aged 65 and over.

DOI： 10.1016/j.jos.2022.11.023

What factors are associated with loss of alignment after open reduction and internal fixation for tibial plateau fractures? A retrospective multicenter (TRON group) study. Reviewed

Keita Shimizu, Yasuhiko Takegami, Katsuhiro Tokutake, Keita Naruse, Yoshito Sudo, Yuji Matsubara, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 1 ) page： 286 - 291 2024.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Tibial plateau fractures (TPFs) are one of the most challenging intra-articular fractures to treat. Along with reconstruction of the articular surfaces, appropriate alignment of the knee joints must be obtained and maintained after open reduction and internal fixation (ORIF) for TPFs because loss of alignment (LA) is associated with worse clinical outcomes. We aimed to investigate and clarify the risk factors related to LA after ORIF for TPFs. METHODS: This multicenter, retrospective cohort study used data of hospitals of the Trauma Research Group (TRON group) from January 1, 2011, to December 31, 2020. Among 293 TPFs extracted from the database, we evaluated the alignment of the articular surface to the anatomical axis of the tibia in the immediate postoperative and last follow-up radiographs. We defined a change of alignment from the immediate postoperative radiograph as LA. We evaluated the risk factors of LA using univariate and multiple logistic regression analyses. RESULTS: LA was observed in 27 fractures (9.2%). In multiple logistic regression analyses, preoperative articular step-off and postoperative condylar widening were statistically associated with LA (OR = 1.1, 95% CI: 1.02-1.19 and P = 0.012; OR = 1.04, 95% CI: 1.00-1.08, P = 0.045, respectively). We calculated the threshold by drawing a receiver operating characteristic curve using the final regression model. The threshold of postoperative widening was 8.2 mm. We divided the 293 TPFs into two groups according to this threshold and determined differences between the two groups using Fisher's exact test. The two groups were statistically significantly different (P = 0.00502). CONCLUSIONS: Preoperative articular step-off and postoperative condylar widening could be associated with LA after ORIF for TPFs. We suggest that intraoperative restoration of condylar widening is important for the prevention of malalignment following ORIF for TPF.

DOI： 10.1016/j.jos.2022.12.008

Predictive factors for one-year mortality after surgery for periprosthetic femoral fracture: A retrospective multicenter (TRON group) study. Reviewed

Hiroshi Kurokawa, Yasuhiko Takegami, Katsuhiro Tokutake, Hideomi Takami, Manato Iwata, Satoshi Terasawa, Hidenori Inoue, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 1 ) page： 299 - 305 2024.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Periprosthetic femoral fracture (PFF) after total hip arthroplasty (THA) or bipolar hip arthroplasty (BHA) represents a challenging situation and the treatment is associated with high rates of complications and mortality. The aims of this multicenter retrospective study were to determine 1-year mortality and to identify predictors associated with mortality, including patient characteristics and surgical factors, in patients undergoing surgery for PFF after THA or BHA. METHODS: We collected 249 cases of PPF after THA or BHA that were treated in our 11 hospitals (named the TRON group) between January 2010 and December 2019. We excluded patients who were conservatively treated, cases in which the 1-year postoperative outcome was unknown, and Vancouver type A cases. Finally, we analyzed 161 patients. Univariate and multivariate Cox regression analyses were performed to identify factors affecting 1-year mortality. Patient-side factors such as age, BMI, fracture type, and preoperative mobility, and surgical factors such as surgical procedure, time to surgery, and operation time were analyzed respectively. RESULTS: Eighteen of 161 patients (11.2%) died one year after surgery. The multivariate Cox regression analysis identified older age, wheelchair status before injury, and operation time as independent predictors of 1-year mortality (older age: hazard ratio [HR] 1.07, 95% CI 1.01-1.15, P = 0.048; wheelchair status: HR 5.82, 95% CI 1.01-33.47, P = 0.049; operation time: [HR] 1.01, 95% CI 1.00-1.01, P = 0.00929). Meanwhile, fracture type according to the Vancouver classification, body mass index, presence of previous fragility fractures, type of ﬁxation, blood loss during operation, and time to surgery were not independent predictors of 1-year mortality in this analysis. ConclusionThe 1-year mortality rate after surgery for PPFs patients was 11.2%. Factors associated with older and poor activity of daily living (ADL) performance (e.g., wheelchair status before injury), and longer operative time were associated with 1-year mortality after surgery for PPF. Surgeons should carefully plan treatment according to each patient's condition.

DOI： 10.1016/j.jos.2022.12.015

Home exercises after volar locking plate fixation for distal radius fracture in the elderly are as effective as supervised physiotherapy -multicenter retrospective study- Reviewed

Yuma Saito, Yasuhiko Takegami, Katsuhiro Tokutake, Ryutaro Shibata, Hiroyuki Matsubara, Shiro Imamaga

Journal of Orthopaedic Science Vol. 29 ( 1 ) page： 146 - 150 2024.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Background: Although home exercises are used for postoperative rehabilitation of distal radius fractures (DRF), the superiority of home exercise over supervised physiotherapy rehabilitation is controversial. This study aimed to compare the function of home exercise and supervised physiotherapy rehabilitation during postoperative rehabilitation for DRF. Methods: We conducted a multicenter, retrospective study in which we included 1949 patients over 65 years old who underwent volar locking plate fixation for DRF. After propensity score matching, 308 patients were assigned to each of an independent home exercise group (IHG) and supervised physiotherapy group (SPG). Wrist function was assessed after 3, 6, and 12 months postoperatively. Results: The results showed that the Mayo Wrist Score did not differ significantly within the observation period. Range of motion of the wrist was better in the SPG up to 3 months postoperatively but was almost the same as that in the IHG at 6 months. However, the Numerical Rating Scale score was lower in the IHG during all observation periods. Conclusions: Home exercise may be as effective as supervised physiotherapy in the medium term, but supervised physiotherapy rehabilitation should be considered if early recovery and good wrist function are desired.

DOI： 10.1016/j.jos.2022.11.017

Early weight bearing versus late weight bearing after intramedullary nailing for distal femoral fracture (AO/OTA 33) in elderly patients: A multicenter propensity-matched study. Reviewed Open Access

Kentaro Komaki, Yasuhiko Takegami, Katsuhiro Tokutake, Masahiro Hanabayashi, Yutaro Kuwahara, Yotaro Yamada, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 29 ( 1 ) page： 268 - 272 2024.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: This study aimed to assess differences in implant failure and bone union rates, amount of change in alignment of lower extremities, and walking ability between early weight-bearing (EWB) and late weight-bearing (LWB) groups following retrograde intramedullary nailing (RIMN) for distal femoral fracture (AO/OTA 33) (DFF) at multiple centers using propensity score matching. METHODS: The data of 213 patients who underwent RIMN from 2012 to 2019 in multiple tertiary hospitals were extracted from our database. Cases with the following factors were excluded: age <60, open fracture, AO/OTA-type 33-C3 fracture, preoperative New Mobility Score (NMS) < 3, postoperative follow-up <3 months, and unknown weight-bearing start time. Eighty-four patients were divided into the EWB and LWB groups. EWB group patients were encouraged to perform partial weight-bearing walking at ≤4 weeks after surgery. LWB group patients were not allowed weight bearing for >4 weeks after surgery. After propensity score matching was applied, 26 cases remained in each group. RESULTS: There were no cases of nail failure in either the EWB group or LWB group (P = 1). Screw failure occurred in 0 cases in the EWB group and in 1 case (4.5%) in the LWB group (P = 1.0). Non-union occurred in 5 patients (19.2%) in the EWB group and 4 patients (15.3%) in the LWB group (P = 1). The mean amount of change in lower extremities alignment did not differ between the two groups. The median Knee Society Score was 95.5 (59-100) vs. 93 (72-100) points (P = 0.39). The median NMS was 7 (0-9) vs. 7 (4-9) points (P = 0.82). CONCLUSIONS: There were no significant intergroup differences in the rates of implant failure, bone union at one year after surgery, amount of change in lower extremities alignment, or walking ability. We suggest that early weight bearing after RIMN for DFF may not be harmful in elderly people.

DOI： 10.1016/j.jos.2022.10.023

An age-matched comparative study on intramedullary nailing and plate fixation of both-bone diaphyseal forearm fracture in adolescents. Reviewed International journal

Noriko Ishihara, Katsuhiro Tokutake, Yasuhiko Takegami, Yuta Asami, Hiroaki Kumagai, Hideyuki Ota, Yoshihiko Kimura, Kazuma Ohshima, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 34 ( 1 ) page： 441 - 450 2024.1

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: This study aimed to compare radiological and functional outcomes and complication rates between intramedullary nailing (IMN) and plate fixation for diaphyseal forearm fractures in adolescents via an age-matched analysis. METHODS: Data were collected from medical records at 11 hospitals from 2009 to 2019, and the age-matched study was conducted between IMN and plate fixation. Functional outcomes, radiographic outcomes, and postoperative complication rates were compared. RESULTS: The IMN group (Group N) and plate fixation group (Group P) each comprised 26 patients after age matching. The mean age after matching was 13.42 years old. Bone maturities at the wrist of the radius and ulna were not significantly different between the two groups (p = 0.764 and p = 1). At the last follow-up period, functional outcomes using the Price criteria were over 90% in both groups, and the rotational range of motion was comparable to that of the healthy side. Over 70% of cases in Group N were performed by closed reduction, and operation time was half that of Group P. Postoperative neurological symptoms and refractures were more common in Group P than in Group N, although not statistically significantly so. CONCLUSIONS: Treatment outcomes for age-matched adolescent diaphyseal forearm fractures were excellent with IMN, as well as with plate fixation in many cases despite fewer complications, better cosmesis, and shorter operative times with IMN. IMN for diaphyseal forearm fractures is a useful treatment option even in adolescents although the indications for the best procedure to perform should be considered depending on individual patient needs. LEVEL OF EVIDENCE IV: Multicenter retrospective study.

DOI： 10.1007/s00590-023-03679-8

Fall risk in patient with dysplastic hip osteoarthritis. Reviewed International journal

Takamune Asamoto, Yusuke Osawa, Yasuhiko Takegami, Masanori Okamoto, Hiroki Iida, Shiro Imagama

International orthopaedics Vol. 48 ( 1 ) page： 221 - 227 2024.1

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Patients with dysplastic hip osteo arthritis (DHOA) often have a spinopelvic imbalance, and they are more likely to experience falls. This study aimed to evaluate the risk factors for falls in patients with DHOA, including spinopelvic parameters. METHODS: In this cross-sectional study, a total of 103 patients with DHOA were included from 2019 to 2021. Fall risk was evaluated using the Fall Risk Index 5 items version (FRI-5). Demographics, functional outcomes, and spinopelvic parameters were compared between the high-risk group (FRI-5 ≥ 6) and the low-risk group (FRI-5 < 6). Multivariate analysis was performed using factors with significant differences in univariate analysis. RESULTS: High-risk and low-risk groups comprised 54 and 49 patients, respectively. Females were significantly more common in the high-risk group than in the low-risk group. The Harris Hip Score was significantly lower in the high-risk group than in the low-risk group (p = 0.02). Pelvic incidence, tilt, and obliquity were significantly higher in the high-risk group than in the low-risk group (p < 0.01). In multivariate analysis, female sex (odds ratio [OR]: 3.76, 95% confidence interval [CI]: 1.11-12.64, p = 0.03), pelvic obliquity (OR: 1.36, 95% CI: 1.09-1.71, p < 0.01), and Harris hip score (OR: 0.96, 95% CI: 0.93-0.99, p = 0.02) were identified as risk factors. CONCLUSION: Female sex, pelvic obliquity, and low Harris hip score were associated with an increased risk of falls among patients with DHOA.

DOI： 10.1007/s00264-023-05938-z

Locked Tension Band Wiring: A Modified Technique for Olecranon Fractures-A Multicenter Study Comparing Clinical Outcomes and Complications with Conventional Methods. Reviewed International journal

Yutaro Kuwahara, Yasuhiko Takegami, So Mitsuya, Katsuhiro Tokutake, Kenichi Yamauchi, Shiro Imagama

Indian journal of orthopaedics Vol. 57 ( 12 ) page： 2024 - 2030 2023.12

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Tension band wiring is the standard treatment for olecranon fractures, but it is associated with high rate of implant-related complication. To reduce this high complication rate, we developed a modified technique, locked tension band wiring (LTBW). The aim of this study was to investigate whether LTBW reduces complication and reoperation rates compared to conventional methods (CTBW). METHODS: We identified 213 olecranon fractures treated with tension band wiring: 183 were treated with CTBW, and 30 were treated with LTBW, and patients in each group were selected using propensity score matching. We evaluated operation time, intraoperative bleeding, complication and reoperation rates, the amount of Kirschner's wire (K-wire) back-out, and Mayo Elbow Performance Index (MEPI). Complications included nonunion, loss of fracture reduction, implant failure, infection, neurological impairment, heterotopic ossification, and implant irritation. Implant removal included at the patient's request with no symptoms. RESULTS: We finally investigated 29 patients in both groups. The mean operation time was significantly longer in the LTBW (106.7 ± 17.5 vs. 79.7 ± 21.1 min; p < 0.01). Complication rates were significantly lower in the LTBW than the CTBW group (10.3 vs. 37.9%; p = 0.03). The rate of implant irritation was more frequent in the CTBW, but there was no significant difference (3.4 vs. 20.7%; p = 0.10). Removal rate was significantly lower in the LTBW (41.4 vs. 72.4%; p = 0.03). The mean amount of K-wire backout at last follow-up was significantly less in the LTBW (3.79 ± 0.65 mm vs. 8.97 ± 3.54 mm; p < 0.01). There were no significant differences in mean MEPI at all follow-up periods (77.4 ± 9.0 vs. 71.5 ± 14.0; p = 0.07, 87.4 ± 7.2 vs. 85.2 ± 10.3; p = 0.40, 94.6 ± 5.8 vs. 90.4 ± 9.0; p = 0.06, respectively). CONCLUSION: Our modified TBW significantly increased operation time compared to conventional method, but reduced the complication and removal rate and had equivalent functional outcomes in this retrospective study.

DOI： 10.1007/s43465-023-01017-y

Association between stem bypass and union failure of subtrochanteric shortening osteotomy in total hip arthroplasty for high hip dislocations

Kazuya Makida, Taisuke Seki, Yasuhiko Takegami, Yusuke Osawa, Shiro Imagama

Journal of Joint Surgery and Research 2023.12

Ulnar Nerve Neuropathy After Surgery for Intraarticular Distal Humerus Fractures: An Analysis of 116 Patients. Reviewed International journal

Yasutaka Oshika, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroki Yokoyama, Takeshi Oguchi, Shiro Imagama

The Journal of hand surgery Vol. 48 ( 11 ) page： 1171.e1 - 1171.e5 2023.11

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: To identify the incidence and the factors associated with a postoperative ulnar nerve neuropathy in patients who had undergone open reduction and internal fixation for intraarticular distal humerus fractures. METHODS: We retrospectively reviewed 116 patients who had undergone surgery between January 2011 and December 2020. Age, sex, BMI, mechanism of injury, open or closed fracture, operation time, tourniquet time, and nerve injury at the final examination were collected from medical charts. We essentially used the paratricipital approach. In cases in which the reduction of intraarticular bone fragments was difficult, olecranon osteotomy was used. Ulnar nerve function was graded according to a modified system of McGowan. We conducted logistic regression analysis to investigate factors of neuropathy using items identified as statistically significant in univariate analysis as explanatory variables. RESULTS: Thirty-four patients (29.3%) had persistent neuropathy at the final follow-up. In the modified McGowan classification, 28 patients had grade 1 and 6 patients had grade 2 neuropathy. Olecranon osteotomy emerged as a distinct explanatory variable for the prophylaxis of ulnar nerve neuropathy in the multivariate analysis (odds ratio, 0.30; 95% confidence interval, 0.12-0.73). Anterior transposition, however, was not a statistically significant factor (odds ratio, 1.91; 95% confidence interval, 0.81-4.56). CONCLUSIONS: Olecranon osteotomy was the only independent factor associated with preventing the occurrence of ulnar nerve neuropathy. Ulnar nerve transposition might not be associated with prevention of ulnar nerve neuropathy. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

DOI： 10.1016/j.jhsa.2023.02.001

Addressing osteoporosis treatment after hemiarthroplasty for a femoral neck fracture: impact on survival rates after a subsequent periprosthetic femoral fracture - a multicenter (TRON group) retrospective study. Reviewed International journal

Yasuhiko Takegami, Yusuke Osawa, Hiroki Iida, Masanori Okamoto, Yuuto Ozawa, Hiroto Funahashi, Hiroaki Ido, Takamune Asamoto, Shiro Imagama

Archives of osteoporosis Vol. 18 ( 1 ) page： 122 - 122 2023.9

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

UNLABELLED: This study investigated the impact of osteoporosis treatment on the prognosis of patients with periprosthetic femoral fracture (PPF) following femoral neck fracture (FNF). Our results suggested an association between osteoporosis treatment and potentially improved survival prognosis in patients who underwent surgery for PPF. These results imply that osteoporosis treatment may have a beneficial effect on patient outcomes. PURPOSE: This study aimed to investigate the effect of osteoporosis treatment on the prognosis of periprosthetic femoral fracture (PPF) patients after femoral neck fracture. METHODS: A multicenter retrospective study named as TRON was conducted. The study population included 156 PPF patients who had undergone hemiarthroplasty for femoral neck fracture between January 2010 and December 2019. Patients were divided based on whether they had received osteoporosis treatment before PPF injury. A log-rank test was used to compare survival rates. We conducted a Cox proportional hazards analysis to identify factors associated with the survival rate after PFF injury. RESULTS: Twenty-seven of the 156 patients had received osteoporosis treatment prior to PPF injury. The 1-year and 2-year overall survival rates after PPF were 80.9% and 75.3%, respectively. The log-rank test revealed that the 1-year survival rate with and without osteoporosis treatment was 89.5% and 78.1%, respectively (P=0.012). In the Cox proportional hazards analysis, age, BMI, presence or absence of surgery, and presence or absence of osteoporosis treatment showed independent associations with the survival rate after PFF injury. The hazard ratio for the presence of osteoporosis treatment was 0.22 (95% confidence interval 0.07-0.75, P=0.015). CONCLUSION: The findings of this study suggest an association between osteoporosis treatment and potentially improved survival prognosis in patients who underwent surgery for PPF. These results imply that osteoporosis treatment may have a beneficial effect on patient outcomes. It is important to consider that osteoporosis treatment could be significant not only in preventing secondary fractures but also in potentially improving prognosis in the rare event of PPF.

DOI： 10.1007/s11657-023-01330-x

Intertrochanteric curved varus osteotomy for subchondral fracture of the femoral head: a case series. Reviewed International journal Open Access

Keiji Otaka, Yusuke Osawa, Yasuhiko Takegami, Taisuke Seki, Shiro Imagama

Arthroplasty (London, England) Vol. 5 ( 1 ) page： 46 - 46 2023.9

Language：English Publishing type：Research paper (scientific journal)

Although favorable results have been reported with total hip arthroplasty, joint-preserving treatment should be the first choice for subchondral fracture of the femoral head (SFF) in young patients. This study reviewed four young male patients with SFF who underwent intertrochanteric curved varus osteotomy (CVO). The patients had a mean age of 32.3 years (range: 18-49 years). Conservative treatment was initially attempted in all cases, but failed to alleviate the pain, leading to surgical intervention at an average time of 6 months (range: 4-10 months) after symptom onset. As the fracture sites were located medial to the lateral edge of the acetabulum in all cases, CVO was performed to achieve a postoperative intact ratio of ≥ 34% in the weight-bearing region of the femoral head. The average follow-up period after surgery lasted 4.3 years (range: 2-7 years). Clinical and radiographic assessments were performed pre- and postoperatively. At the latest follow-up, the mean Harris hip score improved from 67.3 preoperatively to 99.5 postoperatively. The average preoperative intact ratio of the weight-bearing region of the femoral head was 12.3%, which increased to 44.3% postoperatively. No progression to femoral head collapse or joint space narrowing was observed on the plain radiographs. CVO is a simple, less-invasive, and beneficial approach for treating SFF in young patients whose fractures occur medial to the lateral edge of the acetabulum.

DOI： 10.1186/s42836-023-00202-6

Pelvic morphologies of developmental dysplasia and primary osteoarthritis on range of motion after total hip arthroplasty. Reviewed International journal

Hiroto Funahashi, Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Kazuki Nishida, Shiro Imagama

Journal of orthopaedic research : official publication of the Orthopaedic Research Society Vol. 41 ( 9 ) page： 2007 - 2015 2023.9

Language：English Publishing type：Research paper (scientific journal)

Bony impingement, especially in the anterior inferior iliac spine (AIIS) after total hip arthroplasty (THA), may cause dislocation. However, the influence of AIIS characteristics on bony impingement after THA is not fully understood. Thus, we aimed to determine the morphological characteristics of AIIS with developmental dysplasia of the hip (DDH) and primary osteoarthritis (pOA) and to evaluate its effect on range of motion (ROM) after THA. Hips from 130 patients who underwent THA, including primary osteoarthritis (pOA) were analyzed. In total, we had 27 male and 27 female participants with pOA, and 38 male and 38 female participants with DDH. The horizontal distances of AIIS from tear drop (TD) were compared. In the computed tomography simulation, flexion ROM was measured, and its relationship to the distance between TD and AIIS was investigated. DDH had a more medial (male: DDH, 36.9 ± 5.8; pOA, 45.5 ± 6.1; p < 0.001) (female: DDH, 31.5 ± 10.0; pOA, 36.2 ± 4.7; p < 0.001) position of AIIS than pOA. In the male with pOA group, flexion ROM was significantly smaller than that in the other groups, and there was a correlation between flexion ROM and horizontal distances(r = -0.543; 95% confidence interval = -0.765 - -0.206; p = 0.003). AIIS position is a factor that limits ROM during flexion after THA, particularly in males. Further studies are required to develop surgical strategies for cases of impingement at the AIIS site after THA. This article is protected by copyright. All rights reserved.

DOI： 10.1002/jor.25544

Association between Locomotive Syndrome and Hearing Loss in Community-Dwelling Adults. Reviewed International journal Open Access

Sadayuki Ito, Hiroaki Nakashima, Naoki Segi, Jun Ouchida, Shinya Ishizuka, Yasuhiko Takegami, Tadao Yoshida, Yukiharu Hasegawa, Shiro Imagama

Journal of clinical medicine Vol. 12 ( 17 ) 2023.9

Language：English Publishing type：Research paper (scientific journal)

The relationship between hearing and motor function as a function of aging is unclear. Therefore, we aimed to clarify the relationship between age-related hearing loss and locomotive syndrome. In total, 240 participants aged ≥40 years, whose hearing acuity and motor function had been measured, were included in this study. Patients with a hearing acuity of <35 dB and ≥35 dB were categorized into normal and low hearing acuity groups, respectively. Motor function was compared according to sex between the groups. Among men, those in the low hearing acuity group (51/100) were older, had a significantly slower walking speed, and had a higher prevalence of locomotive syndrome than those in the normal group. Among women, those in the low hearing group (14/140) were older and had a significantly slower gait speed than those in the normal group. The multivariate analysis showed that, in the low hearing acuity group, age and gait speed were risk factors in men, while age was the only risk factor in women. In conclusion, hearing loss was associated with walking speed. The association between hearing loss and locomotive syndrome was observed only in men. In the multivariate analysis, hearing loss was associated with walking speed only in men.

DOI： 10.3390/jcm12175626

骨粗鬆症患者の上腕骨近位端骨折においてDeltopectoral approachは術後骨頭壊死のリスクを上昇させる多施設共同研究(TRON study) Reviewed

平松泰, 竹上靖彦, 徳武克浩, 松浦唯, 牧原康一郎, 今釜史郎

日本骨粗鬆症学会雑誌 Vol. 9 ( Suppl.1 ) page： 436 - 436 2023.9

A less invasive operative method using a medial cannulated cancellous screw and single plate fixation for the treatment of transcondylar fracture of the humerus in elderly patients in multicenter (TRON group) study. Reviewed International journal

Kohei Tanaka, Yasuhiko Takegami, Katsuhiro Tokutake, Yasutaka Oshika, Kenya Iwase, Hiroki Yokoyama, Katsuhiro Taguchi, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 33 ( 6 ) page： 2481 - 2487 2023.8

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Double plate fixation for transcondylar fracture (TCF) tends to be more invasive to the soft tissue, and often carries a higher risk of postoperative complications, including ulnar nerve neuropathy. This study presents the outcomes of TCF of the distal humerus between patients treated with a single plate and cannulated cancellous screw fixation and patients treated with double plate fixation. METHODS: Between 2011 and 2021, 371 cases involving treatment of distal humeral fracture were recorded in our multicenter (named TRON group) database. Patients of ≥ 65 years of age with TCF treated with opeb n reduction and internal fixation were included. Clinical outcomes were assessed by the Mayo elbow performance score, range of motion, and total elbow arc joint. Complications included fracture-related infection (FRI) and ulnar neuropathy. RESULTS: There were significant differences in the average operative time (CCS group vs. Plate group: 119.0 min vs. 186.5 min; p < 0.001) and average tourniquet time (CCS group vs. Plate group: 91.5 min vs. 121.0 min; p < 0.001). FRI occurred as a complication in the Plate group (n = 6). The rates of FRI did not differ to a statistically significant extent (CCS group vs. Plate group: 0% vs. 9.2%; p = 0.477). No patients underwent reoperation. The rate of sensory symptoms in the Plate group was higher than that in the CCS group (CCS group: none [n = 25], numbness [n = 1] vs. Plate group: none [n = 57], numbness [n = 15], sensory depression [n = 2]; p = 0.039). DISCUSSION: Among patients of ≥ 65 years of age with TCF, the clinical outcomes of patients treated with medial CCS and lateral/posterolateral plate did not differ from those of patients who received double plate fixation, and the former treatment was associated with significantly fewer complications, including ulnar nerve palsy. In addition to double plate fixation, this less invasive method of medial CCS and single plate fixation should be considered as a treatment option for TCF in elderly patients.

DOI： 10.1007/s00590-022-03464-z

Clinical comparison of double-plate fixation by the perpendicular plate method versus parallel plate method for distal humeral fracture: a multicenter (TRON group) study. Reviewed International journal

Hiroki Yokoyama, Yasuhiko Takegami, Katsuhiro Tokutake, Yasutaka Oshika, Kenya Iwase, Kohei Tanaka, Tokumi Kanemura, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 33 ( 6 ) page： 2427 - 2433 2023.8

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: Double-plating methods are popular, with perpendicular and parallel plate methods being widely used surgical method for the rigid fixation of distal humeral fracture (DHF). However, which plate method is better for DHF remains controversial. The aim of this study was to compare patient outcomes including the incidences of complications and reoperation between the two plate methods. METHODS: We extracted 383 patients with DHF undergoing surgery between 2011 and 2020 from our multicenter database, which is named TRON. We divided the subjects into two groups: perpendicular plating group (Group A) and parallel plating group (Group B). To adjust for baseline differences between the groups, patients were matched for age, sex, olecranon osteotomy, AO type, and type of injury. We assessed the Mayo Elbow Performance Score (MEPS) at 3 and 6 months and the last follow-up month as the clinical outcome. We investigated the incidences of complications and reoperations in both groups. RESULTS: After matching, each group comprised 50 patients. There was no significant difference between Group A versus Group B in MEPS score at each time point. The incidence of implant removal in Group B was higher than that in Group A (26.5% vs 50%, p = 0.023). DISCUSSION: Although there were no significant differences in clinical outcomes or complications between the two groups, the incidence of implant removal was higher in Group B than in Group A. In the parallel plate technique, where the plates have to be placed in areas with thin subcutaneous soft tissue, the incidence of implant removal might be high due to the discomfort caused by the implant.

DOI： 10.1007/s00590-022-03462-1

Retrospective multicenter (TRON group) study of humeral shaft fragility fractures: Analysis of mortality rates and risk factors. Reviewed International journal Open Access

Ken Sato, Yasuhiko Takegami, Katsuhiro Tokutake, Yuya Shimamoto, Hiroki Ueno, Toshihiro Ando, Shiro Imagama

Injury Vol. 54 ( 8 ) page： 110855 - 110855 2023.8

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

AIMS: This study aimed to show the mortality rate following humeral shaft fragility fractures (HSFF) in the elderly. The secondary aim was to examine the predictors associated with mortality in elderly patients who have sustained HSFF. METHODS: From 2011 to 2020, all elderly patients aged 65 years and older with HSFF managed at our nine hospitals were retrospectively identified from our TRON database. Patient demographics and surgical characteristics were extracted from medical records and radiographs, and multivariable Cox regression analysis was used to identify factors affecting mortality. RESULTS: In total, 153 patients who sustained HSFF were included. The mortality rate for HSFF in the elderly was 15.7% at 1 year and 24.6% at 2 years. Multivariable Cox regression analysis showed significant differences in survival for the following variables: older age (p < 0.001), underweight (p = 0.022), severely ill (p = 0.025), mobility limited to indoors (p = 0.003), dominant-side injury (p = 0.027), and nonoperative treatment (p = 0.013). CONCLUSION: The outcome following HSFF in the elderly population appears to be relatively grim. The prognosis of elderly patients with HSFF is closely related to their medical history. In the elderly patients with HSFF, operative treatment should be positively considered while taking into account their medical status.

DOI： 10.1016/j.injury.2023.110855

Predictors of postoperative complications of tension band wiring techniques for patella fracture: A retrospective multicenter (TRON group) study. Reviewed International journal

Hiroki Oyama, Yasuhiko Takegami, Katsuhiro Tokutake, Fuminori Murase, Oki Arakawa, Takeshi Oguchi, Shiro Imagama

Injury Vol. 54 ( 8 ) page： 110896 - 110896 2023.8

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: The relationship between postoperative complications and operative techniques of tension band wiring (TBW) is not well studied. We aimed to evaluate the incidence of implant breakage, implant migration, and loss of reduction in patellar fractures treated with TBW and identify radiographic factors associated with these postoperative complications. METHODS: This multicenter (named, TRON group) retrospective study included 224 patients who underwent open reduction and internal fixation of patella fractures using TBW from January 2016 to December 2020. Radiographic findings were evaluated by experienced orthopedic surgeons, and radiographic outcomes were assessed for K-wire migration, implant breakage, and loss of reduction. Logistic regression analysis was performed to identify radiographic factors associated with postoperative complications. RESULTS: Implant migration occurred in 44 cases (19.6%), with bending of a single K-wire end identified as a significant risk factor (OR: 12.90; 95% CI: 4.99-33.30; P < 0.001). Implant breakage occurred in 43 cases (19.2%), with a large patella-tension band ratio (OR: 291.0; 95% CI: 19.60-4330; P < 0.001) and a wide distance between K-wires (OR: 1.15; 95% CI: 1.060-1.250; P = 0.001) identified as significant risk factors. Loss of reduction occurred in 5 cases (2.0%), but no significant risk factors were identified. CONCLUSION: This study highlights the importance of bending both ends of the K-wires and proper placement of the tension band and K-wires in reducing postoperative complications in patellar fractures treated with TBW. Further research is needed to better understand the risk factors associated with loss of reduction.

DOI： 10.1016/j.injury.2023.110896

Comparison of functional outcome and complications of locking plate versus coracoclavicular fixation in the treatment of unstable distal clavicle fractures: the multicenter, propensity-matched TRON study. Reviewed International journal

Yujiro Katayama, Yasuhiko Takegami, Katsuhiro Tokutake, Nobuyuki Okui, Tadahiro Sakai, Hiroshi Takahashi, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 33 ( 5 ) page： 1789 - 1795 2023.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This multicenter, retrospective study aimed to compare clinical outcomes and complications between locking plate fixation and new coracoclavicular (CC) fixation for patients with unstable distal clavicle fracture. METHODS: We included 142 patients in this TRON study. The mean follow-up was 15.5 (6-31) months. The patients were divided into two groups: the locking plate group (Group L) and CC fixation group (Group C). To adjust for baseline differences between the groups, a propensity score algorithm was used to match two groups in a 1:1 ratio. After matching, we compared operation time and the University of California Los Angeles (UCLA) shoulder score at 3 and 6 months postoperatively and at last follow-up as clinical outcomes and the rate of complications. RESULTS: After matching, 20 cases from each group remained. Operation time was shorter in Group C (75 [22, 111] vs. 100 [38, 120] min; P = 0.023). At 3 months postoperatively, UCLA score in Group C was better, but no significant differences between the groups were found at 6 months and last follow-up after surgery. The rate of complications was not significantly different between the groups. CONCLUSION: CC fixation might be equivalent to locking plate fixation in clinical outcome, and the operation time is shorter than that required for locking plate fixation.

DOI： 10.1007/s00590-022-03358-0

Spinopelvic Imbalance Is Associated With Increased Sway in the Center of Gravity: Validation of the "Cone of Economy" Concept in Healthy Subjects. Reviewed International journal Open Access

Naoki Segi, Hiroaki Nakashima, Kei Ando, Kazuyoshi Kobayashi, Taisuke Seki, Shinya Ishizuka, Yasuhiko Takegami, Masaaki Machino, Sadayuki Ito, Hiroyuki Koshimizu, Hiroyuki Tomita, Yukiharu Hasegawa, Shiro Imagama

Global spine journal Vol. 13 ( 6 ) page： 1502 - 1508 2023.7

Language：English Publishing type：Research paper (scientific journal)

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To investigate the effects of pelvic compensation on standing balance in healthy volunteers. METHODS: The 180 healthy volunteers were recruited at a basic health checkup. The inclusion criteria were: 1) age ≥ 65 years, 2) underwent a whole spine radiograph and stabilometry, 3) well-balanced standing posture with a sagittal vertical axis <50 mm, and 4) a visual analog scale of lower back pain of <20 mm. Based on the pelvic incidence (PI) and lumbar lordosis (LL) mismatch, subjects were divided into harmonious (PI-LL ≤ 10°) or unharmonious (PI-LL > 10°) groups. RESULTS: Participants in the unharmonious group were significantly older compared with the harmonious group (70.2 ± 4.4 vs. 72.0 ± 4.6 years, P < .01). The PI minus LL values were -2.2° ± 7.5° and 16.6° ± 7.0° in the harmonious and unharmonious groups, respectively (P < .001). Anteroposterior LNG/TIME (average center of pressure sway speed) was significantly greater in the unharmonious group with both open and closed eyes (1.04 ± 0.38 cm/s vs. 1.25 ± 0.47 cm/s, P < .001 and 1.22 ± 0.54 cm/s vs. 1.58 ± 0.77 cm/s, P < .001, respectively). Lateral LNG/TIME was significantly greater in the unharmonious group only with closed eyes (1.24 ± 0.54 cm/s vs. 1.47 ± 0.79 cm/s, P = .03). CONCLUSIONS: Healthy elderly subjects with poor spinopelvic harmony had relatively unstable standing balance. The "cone of economy" was demonstrated, showing that unharmonious spinopelvic balance had a non-economic effect on standing.

DOI： 10.1177/21925682211038897

What is the Radiographic Factor Associated with Meniscus Injury in Tibial Plateau Factures? Multicenter Retrospective (TRON) Study. Reviewed International journal Open Access

Keita Naruse, Yasuhiko Takegami, Katsuhiro Tokutake, Keita Shimizu, Yoshito Sudo, Takaaki Shinohara, Shiro Imagama

Indian journal of orthopaedics Vol. 57 ( 7 ) page： 1076 - 1082 2023.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Tibial plateau fracture (TPF) is a complex intra-articular injury involving comminution and depression of the joint, which can be accompanied by meniscal tears. The aims of this study were (1) to demonstrate the rate at which surgical treatment for lateral meniscal injury and (2) to clarify the explanatory radiographic factors associated with meniscal injury in patients with TPF. METHODS: We extracted the patients who received surgical treatment for TPF from our multicenter database (named TRON) included from 2011 to 2020. We analyzed 79 patients who were received surgical treatment for TPF with Schatzker type II and III and evaluation for meniscal injury on arthroscopy. We investigated the rate at which surgical treatment of the lateral meniscus was required in patients with TPF and the explanatory radiographic factors associated with meniscal injury. Radiographs and CT scans were evaluated to measure the following parameters: tibial plateau slope, distance from lateral edge of the articular surface to fracture line (DLE), articular step, and width of articular bone fragment (WDT). Meniscus tears were classified according to whether surgery was necessary. The results were analyzed by multivariate Logistic analyses. RESULTS: We showed that 27.7% (22/79) of cases of TPF with Schatzker type II and III had lateral meniscal injury that required repair. WDT ≥ 10 mm (odds ratio 10.9; p = 0.005) and DLE ≥ 5 mm (odds ratio 5.7; p = 0.05) were independent explanatory factors for meniscal injury with TPF. CONCLUSION: Bone fragment size and the location of fracture line on radiographs in patients with TPF are associated with meniscus injuries requiring surgery. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s43465-023-00888-5.

DOI： 10.1007/s43465-023-00888-5

Incidence and Risk Factors for Fracture-Related Infection After Peri-Prosthetic Femoral Fractures: A Multicenter Retrospective Study (TRON Group Study). Reviewed International journal

Yuji Matsuno, Yasuhiko Takegami, Katsuhiro Tokutake, Hideomi Takami, Hiroshi Kurokawa, Manato Iwata, Satoshi Terasawa, Ken-Ichi Yamauchi, Shiro Imagama

Surgical infections Vol. 24 ( 5 ) page： 433 - 439 2023.6

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Background: Fracture-related infection (FRI) sometimes occurs with peri-prosthetic femoral fracture (PPF) treatment. Fracture-related infection often leads to multiple re-operations, possible non-union, a decreased clinical function, and long-term antibiotic treatment. In this multicenter study, we aimed to clarify the incidence of FRI, the causative organisms of wound infection, and the risk factors associated with post-operative infection for PPF. Patients and Methods: Among 197 patients diagnosed with peri-prosthetic femoral fracture who received surgical treatment in 11 institutions (named the TRON group) from 2010 to 2019, 163 patients were included as subjects. Thirty-four patients were excluded because of insufficient follow-up (less than six months) or data loss. We extracted the following risk factors for FRI: gender, body mass index, smoking history, diabetes mellitus, chronic hepatitis, rheumatoid arthritis, dialysis, history of osteoporosis treatment, injury mechanism (high- or low-energy), Vancouver type, and operative information (waiting period for surgery, operation time, amount of blood loss, and surgical procedure). We conducted a logistic regression analysis to investigate the risk factors for FRI using these extracted items as explanatory variables and the presence or absence of FRI as the response variable. Results: Fracture-related infection occurred after surgery for PPF in 12 of 163 patients (7.3%). The most common causative organism was Staphylococcus aureus (n = 7). The univariable analysis showed differences for dialysis (p = 0.001), Vancouver type (p = 0.036), blood loss during surgery (p = 0.001), and operative time (p = 0.001). The multivariable logistic-regression analysis revealed that the patient background factor of dialysis (odds ratio [OR], 22.9; p = 0.0005), and the operative factor of Vancouver type A fracture (OR, 0.039-1.18; p = 0.018-0.19) were risk factors for FRI. Conclusions: The rate of post-operative wound infection in patients with a PPF was 7.3%. Staphylococcus was the most frequent causative organism. The surgeon should pay attention to infection after surgery for patients with Vancouver type A fractures and those undergoing dialysis.

DOI： 10.1089/sur.2022.347

Comparison of surgical treatments for distal ulna fracture when combined with anterior locking plate fixation of distal radius in the over 70 age group. Reviewed International journal

Ryutaro Shibata, Katsuhiro Tokutake, Yasuhiko Takegami, Tadahiro Natsume, Yuji Matsubara, Shiro Imagama

The Journal of hand surgery, European volume Vol. 48 ( 6 ) page： 516 - 523 2023.6

Language：English Publishing type：Research paper (scientific journal)

We conducted a retrospective multicentre study to compare the clinical and radiographic outcomes, and complications of three surgical treatments of distal ulna fracture (DUF) when combined with anterior locking plate fixation for distal radial fracture (DRF) in patients over 70 years of age. We identified 1521 patients over 70 years of age who were diagnosed as having DRF and who underwent anterior locking plate fixation between 2015 and 2020, among which 122 cases of DUF were analysed. Three surgical treatment options for DUF were identified in this cohort: K-wire fixation (Group K), locking plate fixation (Group L) and Darrach procedure (Group D). The results of the analysis showed the total immobilization period in Group D to be the shortest among the three treatments. Functional outcomes were superior, and the rate of complications were smaller in Group D than in Group L. In addition, rotational range of motion was larger in Group D and Group L compared with Group K. In patients who are 70 years of age or older with combined unstable DRF and highly comminuted or displaced DUF, the Darrach procedure for DUF seems to be the most useful and reasonable treatment option once the fracture of the distal radius has been rigidly fixed.Level of evidence: IV.

DOI： 10.1177/17531934221150495

Factors affecting return to sports after eccentric rotational acetabular osteotomy. Reviewed International journal Open Access

Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Kazuya Makida, Satoshi Ochiai, Yukiharu Hasegawa, Shiro Imagama

Orthopaedics & traumatology, surgery & research : OTSR Vol. 109 ( 4 ) page： 103442 - 103442 2023.6

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Although eccentric acetabular rotation osteotomy (ERAO) is an effective treatment for developmental dysplasia of the hip (DDH), there is little information about return to sports after ERAO. This study aimed to investigate 1) the patient factors that influence the return to sports after ERAO, 2) whether postoperative sports participation will affect future osteoarthritis progression. HYPOTHESIS: Some factors affect the return to sports after ERAO. PATIENTS AND METHODS: Of 503 patients who underwent ERAO from 1990 to 2010, 124 who had been continuously participating in sports preoperatively (average 13.2 years after surgery) were included. Patient demographics of sex, age, body mass index, unilateral to bilateral case ratio, history of treatment for childhood DDH, preoperative Kellgren-Lawrence (KL) grade, center edge angle, joint congruency, Harris hip score, complications and the survival rate were compared between the S group (patients who participated in the same sports preoperatively) and N group (patients who could not participate in sports postoperatively). RESULTS: Seventy-two (58%) and 52 patients (42%) in the S and N groups, respectively, had an overall return to sports rate of 64% (79 patients). The most common sports that patients participated in were swimming (30 patients [24%]), jogging (12 [10%]), and golf (10 [8%]) preoperatively, and swimming (14 patients [11%]), golf (8 [6%]), and jogging (8 [6%]) postoperatively. There were no significant differences between both groups in terms of sex, age, body mass index, unilateral to bilateral case ratio, history of treatment for childhood DDH, preoperative KL grade, and joint congruency. There was a significant difference in patient factors between the S (11 joints [14%]) and N (20 joints [38%]) groups only when the preoperative center edge angle was <0°. There was no significant difference in the preoperative Harris hip score and the final survey between the S (73.2±4.6 and 93.4±7.2) and N (72.5±4.8 and 92.1±7.4) groups. Complications showed no significant differences between the five patients (7%) in the S group and six patients (13%) in the N group. The KL grade progressed in 10 cases (grade II to III in 2 cases and grade III to IV in 8) in the S group and 8 cases (grade II to III in 1 case and grade III to IV in 7 cases) in the N group. The 10-year and 20-year joint survival rates with THA conversion as the endpoint were 98.1% (95% CI: 87.4%-99.7%) and 83.7% (95% CI: 62.6%-93.4%) in the S group and 100% (95% CI: 70.7%-99.3%) and 95.2% (95% CI: 12.6%-92.6%) in the N group, respectively. In the evaluation of factors affecting sports return by logistic regression analysis, only one significant factor (odds ratio 3.42, 95% confidence interval: 1.58-7.42, p<0.01) was the preoperative center edge angle <0°. DISCUSSION: The chief factor affecting the return to sports after surgery was a preoperative center edge angle <0°; moreover, the continuation of sports did not affect the subsequent progression of osteoarthritis or THA conversion. LEVEL OF EVIDENCE: level III, cohort study.

DOI： 10.1016/j.otsr.2022.103442

Early weight bearing and mobilization decrease perioperative complications in patients after ankle fracture; the retrospective multicenter (TRON group) study. Reviewed Open Access

Kosuke Bando, Yasuhiko Takegami, Toshihiro Ando, Takayuki Sugino, Toshifumi Sato, Tomoki Fujita, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 28 ( 3 ) page： 651 - 655 2023.5

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Open reduction and internal fixation (ORIF) for unstable ankle fractures (AF) are relatively predictable with excellent outcomes. Rehabilitation strategies are still being debated after surgical intervention for AF: non-weight bearing and cast immobilization for six weeks after the surgical repair of unstable AF or early functional treatment with partial weight bearing. This study aimed to compare early weight bearing and functional outcomes and complications. METHODS: Between April 2014 and March 2019, 1421 patients with AF underwent ORIF at 11 institutions (TRON group). The patients were divided into two groups: Group E started weight bearing within six weeks after surgery, and group L started weightbearing for more than six weeks after. To adjust for baseline difference between groups, a propensity score-matched algorithm was used to match Group E with Group L in a 1:1 ratio of 294 cases each. We compared the American Orthopedic Foot and Ankle Society (AOFAS) score as the functional outcome, the rate of wound dehiscence, superficial and deep infections, blistering, nonunion, neurapraxia, and reoperation at 3, 6, and 12 months after surgery. RESULTS: The mean period of non-weight bearing was significantly shorter in group E (3.68 ± 1.02 vs. 6.67 ± 1.43; P < 0.001). The mean period of cast immobilization term were shorter in group E (1.84 ± 1.35 vs. 2.65 ± 1.51; P < 0.001). There were no differences in the AOFAS score at any period. The rates of deep infection and reoperation in Group E were significantly lower than those in Group L (1.7% vs. 6.1%; P = 0.009, 2.0% vs. 7.8%; P = 0.002, respectively). There were no significant differences in superficial infection (9 vs. 15; P = 0.297), nonunion (9 vs. 15 P = 0.30), blistering (4 vs. 3; P = 1.00), neurapraxia (2 vs. 1; P = 1.00), and wound dehiscence (15 vs. 18; P = 0.72). CONCLUSIONS: Although functional outcome was similar depending on whether early weight bearing was allowed, the rates of deep infection and reoperation decreased in patients with early weight bearing. We recommend early postoperative weight bearing in patients with a surgically treated AF.

DOI： 10.1016/j.jos.2022.03.002

Low body mass index is a risk factor for increased post-operative mortality and poor functional improvement in distal femur fractures among patients aged over 65: A multicentre (TRON) study. Reviewed Open Access

Yutaro Kuwahara, Yasuhiko Takegami, Katsuhiro Tokutake, Yotaro Yamada, Kentaro Komaki, Shiro Imagama

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 28 ( 3 ) page： 631 - 636 2023.5

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Distal femur fractures have been reported to have a mortality rate comparable to hip fractures, but the risk is still unknown. Recent studies have reported that low body mass index (BMI) is a risk factor for mortality in the elderly. We investigated the efficacy of low BMI for predicting the risk of mortality in distal femur fractures in patients aged over 65 within 18 months after injury and its impact on postoperative clinical outcomes and mortality. METHODS: Data from patients followed for more than six months were obtained from our trauma research group's database. We investigated risk factors for increased mortality using Cox proportional hazards models. We divided the analysed cases into low (<18.5 kg/m2) and high (>18.5 kg/m2) BMI groups. We adjusted the background characteristics of the groups by patient matching, and evaluated the postoperative mortality, complication rate, and knee society score (KSS). RESULTS: We identified 216 patients, including 58 (26.9%) with low BMI values. Low BMI was an independent risk factor for mortality in all models (Hazard Ratio: 2.9, p = 0.011). The overall survival rate of the low BMI group at 18 months was significantly lower than that of the high BMI group (70.7% vs. 89.1%; p = 0.003). The complication rates of the low BMI and high BMI groups were not significantly different (33.3% vs. 22.2%; p = 0.283). The mean KSS values at 3, 6, and 12 months in the low BMI group was significantly worse than that in the high BMI group (78.7 ± 16.2 vs. 84.8 ± 13.1; p = 0.035, 82.2 ± 16.9 vs. 89.7 ± 8.9; p = 0.005, 86.4 ± 13.0 vs. 91.4 ± 8.4; p = 0.020, respectively). CONCLUSIONS: Our study indicated that low BMI was independent associated with increased mortality and impaired postoperative functional recovery in distal femur fractures of the elderly patients.

DOI： 10.1016/j.jos.2022.01.014

Factors affecting sports participation after total hip arthroplasty. Reviewed International journal

Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Daisaku Kato, Genta Takemoto, Shiro Imagama

International orthopaedics Vol. 47 ( 5 ) page： 1181 - 1187 2023.5

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The purpose of this study was to investigate the rate of return to sports after total hip arthroplasty (THA) in patients who regularly participate in sports and evaluate the factors that can affect the return to sports. METHODS: In total, 165 patients who had been continuously participating in sports prior to surgery were included from a total of 401 patients who underwent THA from 2015 to 2018. The mean follow-up was 3.3 (range, 2-6) years. Demographics, medical history, surgical parameters, functional outcomes, and anxiety about complications at the final follow-up were compared between the patients who participated in the same sports as before surgery (S group) and those who could not (N group). RESULTS: The overall return to sports rate was 79% for 68 (41%) and 97 (59%) patients in the S and N groups, respectively. The most common sports that patients participated in post-operatively were walking (76 patients, 46%) and swimming (37 patients, 22%), followed by muscle training (25 patients, 15%). There were significant differences between the groups in the following patient factors: sex, primary disease, post-operative Japanese Orthopedic Association Hip-Disease Evaluation Questionnaire outcome, and anxiety about falls and dislocation. In the evaluation of factors affecting return to sports using logistic regression analysis, male sex (odds ratio 3.66, 95% confidence interval 1.13-11.19, p = 0.029) and anxiety of dislocation (odds ratio 3.42, 95% confidence interval 1.58-7.42, p < 0.01) were extracted as independent risk factors. CONCLUSION: Careful patient guidance and rehabilitation, in addition to accurate surgical procedures, will improve patient participation in sports.

DOI： 10.1007/s00264-023-05724-x

Hook plate fixation versus locking plate fixation for distal clavicle fracture: a multicenter propensity score-matched study Reviewed

Takahashi Hiroshi, Takegami Yasuhiko, Tokutake Katsuhiro, Katayama Yujiro, Imagama Shiro

Nagoya Journal of Medical Science Vol. 85 ( 2 ) page： 223 - 232 2023.5

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Nagoya University Graduate School of Medicine, School of Medicine

Hook plate fixation and locking plate fixation are two standard internal fixation implants for treating distal clavicle fractures. We aimed to clarify the following: 1) Does the locking plate offer better clinical outcomes than the hook plate? 2) Is bone union better with a locking plate than hook plate? and 3) Are complications different between the locking plate and hook plate? We conducted a retrospective multicenter study of 338 patients who underwent surgery from 2014 to 2018 in our 10 hospitals, which comprise the TRON group. Of them, 208 patients treated using any plates were eligible. After 30 patients were excluded for various reasons, 178 patients were included. We classified them into two groups, locking plate group (Group L) and hook plate group (Group H), using propensity score matching. We confirmed bone union with an X-ray, evaluated the UCLA shoulder score, and compared the frequency of complications. After matching, Group L and Group H included 49 patients each. The UCLA score was higher in Group L than in Group H at each follow-up point. We confirmed bone union in all patients in Group L, but it was not confirmed in three patients (6.1%) in Group H. No statistically significant differences were observed except for plate migration, which was observed in nine patients (18.4%) in Group H but in no patients in Group L. The postoperative UCLA score was significantly better in Group L. We recommend the locking plate as a surgical treatment for distal clavicle fractures.

DOI： 10.18999/nagjms.85.2.223

Locked Tension Band Wiring for Mayo IIA Olecranon Fractures: Modified Surgical Technique and Retrospective Comparative Study of Clinical Outcomes and Cost-effectiveness with Locking Plate. Reviewed International journal

Yutaro Kuwahara, Yasuhiko Takegami, So Mitsuya, Katsuhiro Tokutake, Kenichi Yamauchi, Shiro Imagama

The journal of hand surgery Asian-Pacific volume Vol. 28 ( 02 ) page： 205 - 213 2023.4

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Background: Tension band wiring (TBW) has traditionally been used for simple olecranon fractures, but due to its many complications, locking plate (LP) is increasingly being employed. To reduce the complications, we developed a modified technique for olecranon fracture repair, locked TBW (LTBW). The study aimed to compare (1) the frequency of complications and re-operations between LP and LTBW techniques, (2) clinical outcomes and the cost efficacy. Methods: We retrospectively evaluated data of 336 patients who underwent surgical treatment for simple and displaced olecranon fractures (Mayo Type ⅡA) in the hospitals of a trauma research group. We excluded open fractures and polytrauma. We investigated complication and re-operation rates as primary outcomes. As secondary outcomes, Mayo Elbow Performance Index (MEPI) and the total cost, including surgery, outpatients and re-operation, were examined between the two groups. Results: We identified 34 patients in the LP group and 29 patients in the LTBW group. The mean follow-up period was 14.2 ± 3.9 months. The complication rate in the LTBW group was comparable to that in the LP group (10.3% vs. 17.6%; p = 0.49). Re-operation and removal rates were not significantly different between the groups (6.9% vs. 8.8%; p = 1.000 and 41.4% vs. 58.8%; p = 1.00, respectively). Mean MEPI at 3 months was significantly lower in the LTBW group (69.7 vs. 82.6; p < 0.01), but mean MEPI at 6 and 12 months were not significantly different (90.6 vs. 85.2; p = 0.06, 93.9 vs. 95.2; p = 0.51, respectively). The mean cost/patient of the total cost in the LTBW group were significantly lower than those in the LP group ($5,249 vs. $6,138; p < 0.001). Conclusions: This study showed that LTBW achieved clinical outcomes equivalent to those of LP and was significantly more cost effective than LP in the retrospective cohort. Level of Evidence: Level III (Therapeutic).

DOI： 10.1142/S2424835523500224

思春期小児前腕骨骨幹部骨折に対する髄内釘とPlateでの治療成績の比較 Reviewed

石原典子, 徳武克浩, 竹上靖彦, 矢崎尚哉, 熊谷寛明, 太田英之

日本手外科学会雑誌 Vol. 40 ( 1 ) page： O17 - 1 2023.4

Longer time of implantation using the buried pin technique for intramedullary nailing would decrease refracture in the diaphyseal forearm fracture in children-retrospective multicenter (TRON) study. Reviewed International journal

Kazuma Ohshima, Katsuhiro Tokutake, Yasuhiko Takegami, Yuta Asami, Yuji Matsubara, Tadahiro Natsume, Yoshihiko Kimura, Noriko Ishihara, Shiro Imagama

Injury Vol. 54 ( 3 ) page： 924 - 929 2023.3

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Intramedullary nailing using Kirschner wires in pediatric diaphyseal forearm fractures is often performed as a less invasive treatment than plate fixation, but it remains controversial whether the tips of Kirschner wires are buried or exposed. The purpose of this study was to investigate the relationship between whether the tips are buried or exposed and complications, especially of refracture. METHODS: Data of 405 patients under 16 years who underwent surgical treatment for diaphyseal forearm fractures in our 11 hospitals between 2010 and 2020 were collected. Finally, 143 patients who underwent intramedullary nailing with at least 6-month follow-up were analyzed. We investigated difference in complication rates depending on whether the Kirschner wire tips were buried (Group B: n = 79) or exposed (Group E: n = 64). Regarding refractures, we also examined time of onset and status of bone union before the refracture occurred. RESULTS: The duration before implant removal in Group B was more than 4 times longer than that in Group E (mean 187.9 vs. 41.4 days, p<0.001), although there was no significant difference in the progression of bone union between the two groups. Regarding postoperative complications, Group B had a significantly lower rate of refractures than Group E (7.9% vs. 32.8%, p<0.001), although the rate of irritation pain was significantly higher (15.2% vs. 1.6%, p = 0.006). The infection rate was also lower in Group B than Group E, but not significantly so (3.8% vs. 10.9%, p = 0.112). Refractures between 3 and 9 months after surgery accounted for 66.7% of all refractures, and those within 3 months accounted for 14.5% of all fractures. There was no significant difference in the status of bone union before the refracture occurred between patients with and without refracture. CONCLUSIONS: The present study showed that longer time of implantation using the buried pin technique for intramedullary nailing reduces refracture of pediatric diaphyseal forearm fractures. Because of the risk of refracture during remodeling, we recommend the implantation of intramedullary nailing for 6-9 months and the instruction for the patients and the parents to pay more attention to refracture at least within 9 months postoperatively. LEVEL OF EVIDENCE: Level Ⅲ, Multicenter retrospective study.

DOI： 10.1016/j.injury.2023.01.025

Comparison of the Relationship between Visual Acuity and Motor Function in Non-Elderly and Elderly Adults. Reviewed International journal Open Access

Sadayuki Ito, Hiroaki Nakashima, Masaaki Machino, Naoki Segi, Shinya Ishizuka, Yasuhiko Takegami, Jun Takeuchi, Jun Ouchida, Yukiharu Hasegawa, Shiro Imagama

Journal of clinical medicine Vol. 12 ( 5 ) 2023.3

Language：English Publishing type：Research paper (scientific journal)

This study aimed to clarify the relationship between visual acuity and motor function in younger and elderly participants and to compare differences between non-elderly and elderly participants. In total, 295 participants who underwent visual and motor functional examinations were included; participants with visual acuity ≥0.7 were assigned to the normal group (N group) and those with visual acuity ≤0.7 were assigned to the low-visual-acuity group (L group). Motor function was compared between the N and L groups; the analysis was performed by grouping participants into those aged >65 years (elderly) and those aged <65 years (non-elderly). The non-elderly group (average age, 55.6 ± 6.7 years) had 105 and 35 participants in the N and L groups, respectively. Back muscle strength was significantly lower in the L group than in the N group. The elderly group (average age, 71.1 ± 5.1 years) had 102 and 53 participants in the N and L groups, respectively. Gait speed was significantly lower in the L group than in the N group. These results reveal differences in the relationship between vision and motor function in non-elderly and elderly adults and indicate that poor vision is associated with lower back-muscle strength and walking speed in younger and elderly participants, respectively.

DOI： 10.3390/jcm12052008

高齢者橈骨遠位端骨折に伴う尺骨遠位端骨折に対する鋼線固定手術と尺骨頭切除術の比較多施設後ろ向き研究(TRON study) Reviewed

柴田隆太郎, 徳武克浩, 竹上靖彦, 三矢聡, 山内健一, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 2 ) page： S134 - S134 2023.3

テーパーウェッジステムで治療された高齢大腿骨頸部骨折患者におけるcanal fill ratioとステム沈下との関連 Reviewed

中島良, 竹上靖彦, 徳武克浩, 山本茂人, 内藤健太, 小倉啓介, 金村徳相, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 3 ) page： S1161 - S1161 2023.3

上腕骨遠位端関節内骨折(AO/OTA type C)術後の尺骨神経麻痺の発生に関わる因子の検討多施設共同研究TRON study Reviewed

大鹿泰嵩, 竹上靖彦, 徳武克浩, 岩瀬賢哉, 田中耕平, 横山弘樹, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 3 ) page： S938 - S938 2023.3

上腕骨遠位端骨折に対するdouble-plating固定法の臨床成績の比較多施設共同研究(TRON Study) Reviewed

横山弘樹, 竹上靖彦, 徳武克浩, 大鹿泰嵩, 田中耕平, 岩瀬賢哉, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 3 ) page： S935 - S935 2023.3

人工股関節周囲骨折に対する手術治療後の死亡率とその予後にかかわる因子の検討多施設共同後ろ向き研究(TRON study) Reviewed

黒川寛, 竹上靖彦, 徳武克浩, 高見英臣, 岩田愛斗, 寺澤慧, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 3 ) page： S1076 - S1076 2023.3

人工股関節周囲骨折後の骨折関連感染の発生率とリスクファクター(多施設共同レトロスペクティブスタディTRON study) Reviewed

松野優司, 竹上靖彦, 徳武克浩, 高見英臣, 黒川寛, 岩田愛斗, 寺澤慧, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 2 ) page： S156 - S156 2023.3

人工関節周囲大腿骨骨折のVancouver type Bの治療成績多施設共同後ろ向き研究(TRON Study) Reviewed

高見英臣, 竹上靖彦, 徳武克浩, 岩田愛斗, 寺澤慧, 黒川寛, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 3 ) page： S1169 - S1169 2023.3

整形外科領域におけるAI 胸部X線写真から骨密度を推測するAI医療機器の開発 Reviewed

佐藤洋一, 高原俊介, 山本乃利男, 稲垣直哉, 朝本学宗, 牧聡, 竹上靖彦, 斎藤充, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 3 ) page： S656 - S656 2023.3

肘頭骨折に対するLocked tension band wiringと従来法との比較多施設共同研究 Reviewed

桑原悠太郎, 竹上靖彦, 徳武克浩, 小口武, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 3 ) page： S936 - S936 2023.3

高齢者の橈骨遠位端骨折プレート固定後のリハビリでの自宅療法と作業療法の中期的な機能成績の比較 TRON study Reviewed

斎藤雄馬, 竹上靖彦, 徳武克浩, 柴田隆太郎, 森悠祐, 嵯峨咲, 川崎雅史, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 2 ) page： S337 - S337 2023.3

整形外科インプラントの物流にかかるコストの基礎研究 Reviewed

山下暁士, 大山慎太郎, 山下佳子, 池田健一, 石塚真哉, 竹上靖彦, 今釜史郎

日本整形外科学会雑誌 Vol. 97 ( 3 ) page： S1215 - S1215 2023.3

Retrospective Comparative Study of Clinical Outcomes and Cost-Effectiveness with Bone Substitutes on Volar Locking Plate Fixation of Unstable Distal Radial Fractures in the Elderly. Reviewed International journal

Yusuke Mori, Yasuhiko Takegami, Katsuhiro Tokutake, Yoshiharu Oka, Shiro Imagama

The journal of hand surgery Asian-Pacific volume Vol. 28 ( 1 ) page： 61 - 68 2023.2

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Background: This multicenter retrospective study aimed to compare clinical outcomes and cost-effectiveness with bone substitutes on volar locking plate (VLP) fixation of unstable distal radial fractures (DRF) in the elderly. Methods: The data of 1,980 patients of ≥65 years of age who underwent surgery for the DRF with a VLP in 2015-2019 were extracted from a database (named TRON). Patients lost to follow-up or who received autologous bone grafting were excluded. The patients (n = 1,735) were divided into the VLP fixation alone (Group VLA) and VLP fixation with bone substitutes (Group VLS). Propensity score matching of background characteristics (ratio, 4:1) was performed. The modified Mayo wrist scores (MMWS) were evaluated as clinical outcomes. The implant failure rate, bone union rate, volar tilt (VT), radial inclination (RI), ulnar variance (UV) and distal dorsal cortical distance (DDD) were evaluated as radiologic parameters. We also compared the initial surgery cost and total cost for each group. Results: After matching, the backgrounds of Groups VLA (n = 388) and VLS (n = 97) were not significantly different. The MMWS values of the groups were not significantly different. Radiographic evaluation revealed no implant failure in either group. Bone union was confirmed in all patients in both groups. The VT, RI, UV and DDD values of the groups were not significantly different. The initial surgery cost and total cost in the VLS group were significantly higher than those in the VLA group ($3,515 vs. $3,068, p < 0.001). Conclusions: In patients of ≥65 years of age with DRF, the clinical and radiological outcomes of VLP fixation with bone substitutes did not differ from those of VLP fixation alone, yet the additional use of bone augmentation was associated with higher medical costs. The indications for bone substitutes should be more strictly considered in the elderly with DRF. Level of Evidence: Level IV (Therapeutic).

DOI： 10.1142/S2424835523500091

Are the Clinical Results of Locking Plate Fixation for Distal Radius Fractures Inferior in Patients over 80 Years of Age? A Multicentre (TRON Group) Study. Reviewed International journal Open Access

Saki Sakurai, Yasuhiko Takegami, Katsuhiro Tokutake, Yutaro Kuwahara, Ryutaro Shibata, Hideyuki Ota, Hiroaki Kumagai, Shiro Imagama

Indian journal of orthopaedics Vol. 57 ( 1 ) page： 117 - 123 2023.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: With the aging of the population, the proportion of distal radius fracture patients who are > 80 years of age is increasing. In this study, we compared the postoperative clinical and radiographic outcomes between super-elderly patients (age: ≥ 80 years) and middle-elderly (age: 65-79 years) who were treated with volar locking plate (VLP) fixation for distal radius fractures. PATIENTS AND METHODS: Patients of > 65 years of age with distal radius fractures treated by VLP fixation between 2015 and 2019, and who were followed for at least 6 months after surgery were included in our database (named TRON). Patients with open fractures, multiple-trauma, or who received fixation with implants other than a VLP were excluded. We evaluated postoperative complications, Mayo wrist score (MWS), and radiographic outcomes. RESULTS: We identified 589 patients in this study; 452 were 65-79 years of age (Group A) and 137 were ≥ 80 years of age (Group B). After propensity score matching, we evaluated 309 patients in Group A and 103 patients in Group B. The mean follow-up period was 10.7 ± 4.6 months. Twenty-eight patients (9.1%) in Group A and 5 patients in Group B (4.9%) experienced post-operative complications (non-significant: p = 0.212). The postoperative MWS at 1, 3, and 6 months, respectively, was 65.4 ± 11.7, 75.2 ± 11.0, and 79.6 ± 10.5 in Group A and 67.1 ± 9.61, 75.7 ± 10.7, and 80.6 ± 9.7 in Group B (non-significant: p = 0.418, 0.893, 0.452, respectively). The differences in volar tilt, radial inclination, ulnar variance between the postoperative and last follow-up radiographs did not differ between the two groups to a statistically significant extent (p = 0.053, 0.437, 0.529, respectively). CONCLUSION: Our study showed that the clinical and radiographic outcomes of distal radius fractures treated with VLP in super-elderly patients were comparable to those in middle-elderly patients.

DOI： 10.1007/s43465-022-00788-0

Mortality and clinical outcomes of Vancouver type B periprosthetic femoral fractures : a multicentre retrospective study. Reviewed International journal Open Access

Hideomi Takami, Yasuhiko Takegami, Katsuhiro Tokutake, Hiroshi Kurokawa, Manato Iwata, Satoshi Terasawa, Takeshi Oguchi, Shiro Imagama

Bone & joint open Vol. 4 ( 1 ) page： 38 - 45 2023.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

AIMS: The objectives of this study were to investigate the patient characteristics and mortality of Vancouver type B periprosthetic femoral fractures (PFF) subgroups divided into two groups according to femoral component stability and to compare postoperative clinical outcomes according to treatment in Vancouver type B2 and B3 fractures. METHODS: A total of 126 Vancouver type B fractures were analyzed from 2010 to 2019 in 11 associated centres' database (named TRON). We divided the patients into two Vancouver type B subtypes according to implant stability. Patient demographics and functional scores were assessed in the Vancouver type B subtypes. We estimated the mortality according to various patient characteristics and clinical outcomes between the open reduction internal fixation (ORIF) and revision arthroplasty (revision) groups in patients with unstable subtype. RESULTS: The one-year mortality rate of the stable and unstable subtype of Vancouver type B was 9.4% and 16.4%. Patient demographic factors, including residential status and pre-injury mobility were associated with mortality. There was no significant difference in mortality between patients treated with ORIF and Revision in either Vancouver B subtype. Patients treated with revision had significantly higher Parker Mobility Score (PMS) values (5.48 vs 3.43; p = 0.00461) and a significantly lower visual analogue scale (VAS) values (1.06 vs 1.94; p = 0.0399) for pain than ORIF in the unstable subtype. CONCLUSION: Among patients with Vancouver type B fractures, frail patients, such as those with worse scores for residential status and pre-injury mobility, had a high mortality rate. There was no significant difference in mortality between patients treated with ORIF and those treated with revision. However, in the unstable subtype, the PMS and VAS values at the final follow-up examination were significantly better in patients who received revision. Based on postoperative activities of daily life, we therefore recommend evision in instances when either treatment option is feasible.Cite this article: Bone Jt Open 2023;4(1):38-46.

DOI： 10.1302/2633-1462.41.BJO-2022-0145.R1

Hip function in patients undergoing conservative treatment for osteonecrosis of the femoral head. Reviewed International journal

Yusuke Osawa, Yasuhiko Takegami, Daisaku Kato, Masanori Okamoto, Hiroki Iida, Shiro Imagama

International orthopaedics Vol. 47 ( 1 ) page： 89 - 94 2023.1

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Once collapsed, osteonecrosis of the femoral head (ONFH) generally obtains collapse cessation naturally and surgical intervention can be avoided in the long term. This study aimed to investigate the process of hip function and secondary osteoarthritis changes in ONFH patients undergoing conservative treatment. METHODS: We included 54 patients with symptomatic ONFH at the first visit with a minimum follow-up of three years with conservative treatment. Patients were divided into two groups based on collapse cessation < 3 mm (stable group) or progression to > 3 mm (progression group). Additionally, we investigated age, sex, body mass index (BMI), etiology, contralateral side hip joint, the Japanese Investigation Committee (JIC) type classification, Harris hip score (HHS), Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), and survival rate with secondary osteoarthritis as the endpoint. RESULTS: The stable and progression groups had 31 and 23 patients, respectively. No significant differences in age, sex, BMI, and aetiology were observed between the two groups, except for the contralateral side hip joint and JIC type classification. The HHS and JHEQ were significantly improved at the final follow-up than at the first visit in the stable group. However, there were no significant differences in HHS and JHEQ at the final follow-up than at the first visit in the progression group. The five year survival rates with secondary osteoarthritis as the endpoint were significantly higher in the stable group (100%) than in the progression group (32.5%). CONCLUSION: Hip joint function improved by continuing conservative treatment in ONFH patients with collapse cessation < 3 mm.

DOI： 10.1007/s00264-022-05569-w

Differences in peri-hip articular pain after total hip arthroplasty between taper wedge stem and fit-and-fill stem. Reviewed International journal Open Access

Daisaku Kato, Yasuhiko Takegami, Taisuke Seki, Yusuke Osawa, Genta Takemoto, Masanori Okamoto, Hiroki Iida, Shiro Imagama

Journal of orthopaedics Vol. 35 page： 58 - 63 2023.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Total hip arthroplasty (THA) for hip disorders helps to alleviate pain and improve active daily life. When determining the effects of medical therapy and the subsequent clinical results, patient quality of life (QOL) also needs to be assessed. Recently, patient-reported outcomes (PRO) have become important as evaluation criteria. This study aimed to evaluate patient QOL and various PRO between different types of cementless stems and to clarify the relationship between PRO and stem-cortical bone contact. METHODS: The study comprised 138 consecutive patients undergoing cementless THA for hip osteoarthritis. We assessed three different types of PRO: the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), patient's joint perception, and peri-hip articular joint pain (PHAP). We measured the state of contact between femur and implant by density mapping. RESULTS: No significant difference was noted in PRO between stem types based on the JHEQ and patient's joint perception. PHAP occurred more frequently in the patients with a taper wedge stem versus a fit-and-fill stem. In both groups, distal contact was associated with PHAP but not with JHEQ results and patient's joint perception. CONCLUSION: The difference in PHAP between the two stem types groups was significant, with postoperative PHAP being higher with the taper wedge stem because of the more distal contact between the taper wedge stem and femur cortical bone.

DOI： 10.1016/j.jor.2022.10.014

Do heel-unloading orthoses improve clinical outcomes in patients after surgical treatment of calcaneal fracture? A propensity-matched, multicenter analysis of the TRON database. Reviewed International journal

Yujiro Kagami, Katsuhiro Tokutake, Yasuhiko Takegami, Nobuyuki Okui, Tadahiro Sakai, Hidenori Inoue, Tokumi Kanemura, Masahiro Hanabayashi, Osamu Ito, Yasuhide Kanayama, Koji Maruyama, Hiroaki Yoshida, Toshihiro Ando, Ryosuke Sugimoto, Takuya Sugimoto, Shiro Imagama

Prosthetics and orthotics international Vol. 46 ( 6 ) page： 569 - 575 2022.12

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Postoperative protocols after surgical treatment of calcaneal fracture have not been standardized to date. There are only a few reports on the efficacy of heel-unloading orthoses (HUOs; Mars shoe, Graffin orthosis), and thier efficacy is uncertain. OBJECTIVES: The purpose of this study was to compare postoperative radiologic and clinical outcomes in patients with calcaneal fractures who used Graffin orthosis. STUDY DESIGN: Multicenter retrospective study. METHODS: We finally extracted 182 patients from a database of the Trauma Research Group of Nagoya and divided them into two groups: group C (underwent casting or splinting only) and group O (Graffin orthosis was used). A propensity score algorithm was used to match group C to group O in a 1:1 ratio. We evaluated American Orthopaedic Foot and Ankle Society (AOFAS) score at three and six months after surgery and at final follow-up. Differences in reduction of the Böhler angle between the two groups were evaluated radiographically. All data were analyzed with a t-test or Fisher's exact test. P < .05 was considered statistically significant. RESULTS: The AOFAS score 3 months after surgery in group O was significantly higher than that in group C (69.57 vs. 77.22; P = .004). However, there were no statistically significant differences between group C vs. group O in AOFAS scores at 6 months after surgery and at final follow-up (81.92 vs. 85.67 and 89.18 vs. 88.13; P = .087 and 0.597, respectively). There was no significant statistical difference in the reduction of the Böhler angle (5.07 vs. 5.89; P = .529). CONCLUSIONS: At 3 months postoperatively, the orthosis group showed predominantly better functional results. We believe that heel-unloading orthoses are useful for patients who require an early return to work and to daily life.

DOI： 10.1097/PXR.0000000000000168

Gain-of-Function of FGFR3 Accelerates Bone Repair Following Ischemic Osteonecrosis in Juvenile Mice. Reviewed International journal

Daisaku Kato, Masaki Matsushita, Yasuhiko Takegami, Kenichi Mishima, Nobuhiro Kamiya, Yusuke Osawa, Shiro Imagama, Hiroshi Kitoh

Calcified tissue international Vol. 111 ( 6 ) page： 622 - 633 2022.12

Language：English Publishing type：Research paper (scientific journal)

Bone collapse, bone deformity, and a long treatment period are major clinical problems associated with juvenile ischemic osteonecrosis (JIO). Accelerating the process of bone repair in JIO is expected to shorten the treatment duration and better maintain morphology. We previously indicated that both bone formation and resorption were accelerated following distraction osteogenesis-mediated limb lengthening in genetically engineered mutant mice with a gain-of-function mutation in fibroblast growth factor receptor 3 (FGFR3) gene (i.e., Fgfr3 mice). The purpose of this study was to investigate the role of FGFR3 in the bone repair process following surgically induced ischemic osteonecrosis in the mutant mice. Epiphyseal deformity was less in the Fgfr3 mice compared to the wild-type mice at 6 weeks following ischemic osteonecrosis in skeletally immature age. Assessment of the morphology by micro-computed tomography (CT) revealed that the trabecular bone volume was increased in the Fgfr3 mice. Dynamic bone histomorphometry revealed increased rates of bone formation and mineral apposition in the Fgfr3 mice at 4 weeks post-surgery. The number of tartrate-resistant acid phosphatase (TRAP)-positive cells rapidly increased, and the numbers of TdT-mediated dUTP nick-end labeling (TUNEL)-positive cells rapidly decreased in the Fgfr3 mice. Vascular endothelial growth factor (VEGF) expression was increased at the earlier phase post-surgery in the Fgfr3 mice. The activation of FGFR3 signaling shortens the time needed for bone repair after ischemic osteonecrosis by accelerating revascularization, bone resorption, and new bone formation. Our findings are clinically relevant as a new potential strategy for the treatment of JIO.

DOI： 10.1007/s00223-022-01019-2

Does surgical treatment for unstable fragility fracture of the pelvis promote early mobilization and improve survival rate and postoperative clinical function? Reviewed International journal

Yuki Saito, Katsuhiro Tokutake, Yasuhiko Takegami, Masahiro Yoshida, Toshifumi Omichi, Shiro Imagama

European journal of trauma and emergency surgery : official publication of the European Trauma Society Vol. 48 ( 5 ) page： 3747 - 3756 2022.10

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This retrospective multicenter study aimed to compare rates of early mobilization and survival and functional outcome of surgical treatment (S) with that of conservative treatment (C) according to each unstable fragility fracture of the pelvis (FFP) classification type with displacement of the posterior component ≥ 5 mm. METHODS: We analyzed 64 patients with unstable type III and IV FFP who could move and transfer themselves before injury and had ≥ 5 mm displacement of the posterior component. We compared survival rate, early mobilization, walking ability at final follow-up, and complications at admission for each type of surgical and conservative treatment. RESULTS: Most of the unstable FFP were type IIIa and IVb in the study population. Type III comprised 40 cases (group S:13/group C:27) and type IV comprised 24 cases (group S:7/group C:17). There were no significant differences in 3 month and 1 year survival rates, although group C (III) had the tendency of higher mortality rate (p = 0.08). Mobilization (transferring to a wheelchair) was enabled significantly earlier in group S (III) than in group C (III) (p = 0.02), but in type IV, most patients enabled early mobilization even without surgical intervention. There were no significant differences in hospital complications and walking ability at final follow-up. CONCLUSION: In this study, the superiority of surgical treatment for unstable FFP was not proven. However, the results suggest that type IVb may be a relatively stable type compared to type III and that type IVb should be considered separately from bilaterally complete unstable sacral fractures due to high-energy trauma.

DOI： 10.1007/s00068-021-01729-6

Plate fixation through the lateral extensile approach versus cannulated screw fixation through the sinus tarsi approach for calcaneal fracture: a multicenter, propensity score-matched TRON study. Reviewed International journal

Takuya Sugimoto, Katsuhiro Tokutake, Yasuhiko Takegami, Nobuyuki Okui, Yasuhide Kanayama, Hidenori Inoue, Ryosuke Sugimoto, Yujiro Kagami, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 32 ( 7 ) page： 1333 - 1340 2022.10

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: For calcaneal fracture, plate fixation through lateral extensive approach (LEP) is the most common procedure performed to achieve anatomic reduction. However, wound complications sometimes occur after LEP. To reduce complications, minimally invasive operative methods with cannulated screw fixation through sinus tarsi approach (STS) were developed. The aim of this multicenter propensity-matched study was to compare the clinical and radiographic outcomes of LEP to those of STS for calcaneal fracture and to evaluate the incidence of postoperative complications including surgical site infection (SSI). METHODS: We extracted 271 patients with calcaneal fracture undergoing surgery between January 2014 and March 2019 from our multicenter TRON database. We assessed the American Orthopedic Foot and Ankle Society (AOFAS) score at the final follow-up as the clinical outcome. We obtained the Bohler and Preis angles as radiographic parameters and also recorded the complications. We divided the subjects into two groups: LEP group and STS group. To adjust for baseline differences between the groups, a propensity score matching algorithm was used in a 1:1 ratio. RESULTS: After matching, there were 32 fractures in each group. There was no significant difference between the LEP versus STS group in AOFAS score at final follow-up (90 vs 90 points, p = 0.98) and in the Bohler and Pries angles (19.2 vs. 18.0 degrees, p = 0.74 and 16.0 vs. 17.5 degrees, p = 0.47). The rate of SSI in the LEP group was higher than that in the STS group (21.9% vs. 0.0%, p = 0.01). CONCLUSION: For calcaneal fracture, STS provides similar fixation effectiveness and functional outcomes as LEP while reducing the likelihood of infection.

DOI： 10.1007/s00590-021-03115-9

Effect of trochanter displacement on impingement and bone contact in total hip arthroplasty performed after curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head: a simulation study. Reviewed International journal Open Access

Masanori Okamoto, Taisuke Seki, Yasuhiko Takegami, Yusuke Osawa, Shiro Imagama

BMC musculoskeletal disorders Vol. 23 ( 1 ) page： 850 - 850 2022.9

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Curved intertrochanteric varus osteotomy (CVO) is a useful treatment option for osteonecrosis of the femoral head (ONFH). However, the effect of proximal femoral deformity in cases of CVO converted to total hip arthroplasty (THA) remains unclear. The aim of this study was to evaluate the effect of trochanter displacement on impingement and the contact state of the implant and femur in THA. METHODS: Thirty-eight hips that had undergone CVO for ONFH were reviewed and compared with a control group of 30 contralateral hips that had not undergone surgery. The range of motion (ROM) and impingement patterns and the percentage of cortical bone in the stem placement within the femur were measured by simulation using CT-based three-dimensional template software. We also measured the ROM and the number of joints that achieved the ROM required for activities of daily living when the upward displaced apex of the greater trochanter with osteotomy was resected and compared the findings with those obtained when the apex was not resected. RESULTS: The CVO group showed a significantly greater bony impingement in external rotation (68.4% vs. 43.3%, p = 0.033) and abduction (78.9% vs. 33.3%, p < 0.001) than in the control group. The CVO group showed a significantly smaller range of external rotation (19.0° [interquartile range; 4.0-28.8] vs. 38.0° [interquartile range; 36.0-41.8], p < 0.001) and abduction (23.0° [interquartile range; 8.5-38.8] vs. 56.0° [interquartile range; 50.3-60.0], p < 0.001) than in the control group. Significantly more joints achieved the ROM necessary for activities of daily living when the apex was resected than when it was not (10.5% vs. 63.2%, p < 0.001). The percentage of cortical bone in the stem placement position was significantly higher in the CVO group than in the control group in the proximal portion of the stem (25.5% vs. 0.0%, p < 0.001). CONCLUSION: In cases requiring conversion to THA, we recommend resecting the upward displaced apex to achieve a sufficient ROM and carefully resecting the bone to avoid malignment of the stem.

DOI： 10.1186/s12891-022-05803-x

Mortality and functional outcomes of fragility fractures of the pelvis by fracture type with conservative treatment: a retrospective, multicenter TRON study. Reviewed International journal

Toshifumi Omichi, Yasuhiko Takegami, Katsuhiro Tokutake, Yuki Saito, Osamu Ito, Toshihiro Ando, Shiro Imagama

European journal of trauma and emergency surgery : official publication of the European Trauma Society Vol. 48 ( 4 ) page： 2897 - 2904 2022.8

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media {LLC}

PURPOSE: Fragility fractures of the pelvis (FFP) are becoming a commonly encountered disease in aging societies. We aimed to (1) clarify the overall survival rate of FFP, (2) compare survival rates by Rommens and Hofmann classification FFP type, (3) investigate the complications during hospitalization, and (4) investigate walking ability before and after injury depending on the type of fracture in patients with FFP treated conservatively. METHODS: This retrospective, multicenter study included 867 patients with FFP treated conservatively between 2014 and 2018 and excluded patients with insufficient follow-up for two years, lost data, and operative cases. This is a retrospective multicenter study. We established the database, which is named as TRON. We evaluated survival rate by fracture type using the log-rank test. We compared walking ability as defined by a new mobility score and the modified Majeed Pelvic Score among fracture types. RESULTS: We reviewed 552 cases (98 males and 454 females) with conservative treatment. The overall survival rates of patients with FFP treated conservatively were 0.90 at 1 year and 0.83 at 2 years. Although the survival rate was the lowest in FFP Type III, there was no significant difference in survival rates between fracture types (P = 0.143). The rates of complications during hospitalization were high for both Type III and Type IV fractures. Walking ability post-injury was worse in the patients with Type III fracture. CONCLUSIONS: The survival rate of patients treated by conservative treatment was relatively good. Type III in the Rommens and Hofmann classification was related to lower life expectancy and loss of walking ability.

DOI： 10.1007/s00068-021-01839-1

Risk factors for fracture-related infection after open reduction and internal fixation of proximal humerus fractures: A multicenter retrospective study of 496 fractures (TRON group study). Reviewed International journal

Koichiro Makihara, Yasuhiko Takegami, Katsuhiro Tokutake, Kenichi Yamauchi, Yutaka Hiramatsu, Yui Matsuura, Shiro Imagama

Injury Vol. 53 ( 7 ) page： 2573 - 2578 2022.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: One of the complications of the surgical therapy for proximal humerus fractures is fracture-related infection (FRI). This multicenter study aimed to investigate the incidence of FRI and clarify the risk factors associated with FRI in patients receiving open reduction and internal fixation for proximal humerus fracture. MATERIAL AND METHODS: Among 684 patients diagnosed as having proximal humerus fracture and who were treated by surgical therapy in 13 institutions (named TRON group) from 2015 through 2020, 496 patients (men, n = 134, women, n = 362; mean [SD] age, 68.5 [14.5] years; mean [SD] body mass index [BMI], 23.0 [4.4] kg/m2) were included as subjects. Excluded were 188 patients due to less than 12 month's follow-up, patients who underwent osteosynthesis using neither plate nor nail and those with open fracture. We extracted the following as risk factors of FRI: sex, BMI, smoking status, diabetes, glenohumeral fracture dislocation, fracture classification, approach, implant, waiting period, type of anesthesia, operative time and blood loss during surgery. We conducted logistic regression analysis to investigate the risk factors of FRI using these extracted items as explanatory variables and the presence or absence of FRI as the response variable. RESULT: FRI occurred after surgery for proximal humerus fracture in 9 of the 496 patients (1.8%). The causative organism was methicillin-susceptible Staphylococcus aureus in 4 patients, Pseudomonas aeruginosa in one patient and Enterococcus faecalis in one patient. In the other 3 patients, causative organisms were not detected. The univariate analysis showed significant differences for present of glenohumeral fracture dislocation (p = 0.004). Logistic regression analysis showed glenohumeral fracture dislocation to be the significant explanatory factor for FRI (odds ratio 12.3, p = 0.0375). CONCLUSION: This study revealed an infection rate following open reduction and internal fixation of proximal humerus fracture of 1.8% (9 patients) and that Staphylococcus was the most frequent causative organism. Glenohumeral fracture dislocation is a significant risk for postoperative FRI.

DOI： 10.1016/j.injury.2022.05.022

The Association of Bohler's Angle With Postoperative Pain and Gender for Displaced Intra-Articular Calcaneal Fracture, Multicenter Retrospective Study-TRON Study. Reviewed International journal Open Access

Ryosuke Sugimoto, Katsuhiro Tokutake, Yasuhiko Takegami, Yasuhide Kanayama, Nobuyuki Okui, Tadahiro Sakai, Yujiro Kagami, Takuya Sugimoto, Shiro Imagama

The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons Vol. 61 ( 4 ) page： 766 - 770 2022.7

Language：English Publishing type：Research paper (scientific journal)

A relationship between Böhler angle (BA) before or after surgery and clinical outcomes remains unclear. This retrospective multicenter cohort study aimed to compare pain and functional outcomes between a group in which the reduction angle was preserved and a group in which the reduction angle was lost during follow-up, and to clarify the risk factors leading to loss of last follow-up BA. From 2014 to 2018, 271 cases of calcaneal fractures were surgically treated at ten facilities. We divided patients into Group L (lost reduction of fracture) and Group P (preserved reduction of fracture). We matched subjects between the 2 groups according to age, sex and BA before surgery and compared American Orthopedic Foot and Ankle Society (AOFAS) score between the groups. We investigated the correlation between the amount of BA loss and postoperative pain. The factors leading to loss of last follow-up BA were examined by logistic regression analysis. Ultimately, 112 patients were eligible. After matching, each group included 38 patients. There was no difference between the 2 groups in total AOFAS score. However, the pain component of AOFAS score at 6 months and 12 months were worse in group L than in group P (p = .011, p = .031, respectively). We also showed a weak correlation between the amount of BA loss and postoperative pain. Logistic regression analysis revealed that female and BA before surgery independently predicted loss of reduction (odds ratios: 4.66, 95% CI: 1.15-18.9 and odds ratios: 0.90, 95% CI: 0.82-0.99, respectively). We clarified that reduction and preservation of BA within its normal range should lead to decrease postoperative pain. Female and lower pre-BA were risk factors leading to loss of reduction of BA in operative treatment of calcaneal fractures.

DOI： 10.1053/j.jfas.2021.11.011

大腿骨遠位端関節外骨折におけるロッキングプレートと逆行性髄内釘の治療成績比較 Reviewed

桑原悠太郎, 竹上靖彦, 徳武克浩, 山田陽太郎, 小牧健太郎, 今釜史郎

骨折 Vol. 44 ( Suppl. ) page： S262 - S262 2022.6

A preliminary examination of the association between locomotive syndrome and circulating miRNA-199 in community-dwelling people: The Yakumo study Reviewed Open Access

Yasuhiko Takegami, Taisuke Seki, Yusuke Osawa, Kazuya Makida, Satoshi Ochiai, Hiroaki Nakashima, Ryosuke Fujii, Hiroya Yamada, Koji Suzuki, Yukiharu Hasegawa, Shiro Imagama

Journal of Orthopaedic Science Vol. 27 ( 3 ) page： 696 - 700 2022.5

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier {BV}

Background: The risk of locomotive syndrome (LS) has been proposed as a criterion for evaluating physical ability. The expression levels of circulating miRNAs (c-miRNAs) are predictors of various diseases. This preliminary study aimed to evaluate the relationship between serum levels of several miRNAs and LS. Methods: We enrolled 423 participants in whom we conducted a survey with the 25-question Geriatric Locomotive Function Scale (GLFS-25) and measured the serum levels of 21 c-miRNAs. The relationship between the GLFS-25 and each c-miRNA was evaluated with a linear regression analysis, and independent associations between the GLFS-25 and each c-miRNA were assessed with a multiple regression analysis using various independent variables. Results: Only the serum level of miR-199 was significantly associated with LS after adjustment for age, BMI, sex, and all comorbidities. The receiver operating characteristics curve for the predictive value of the miR-199 level to indicate the presence or absence of LS risk had an area under the curve (AUC) of 0.576 (95% confidence interval: 0.501–0.651). Conclusion: The expression level of miRNA-199 was associated with the risk of LS in community-dwelling Japanese people.

DOI： 10.1016/j.jos.2021.02.003

Comparison of periprosthetic femoral fracture torque and strain pattern of three types of femoral components in experimental model. International journal Open Access

Yasuhiko Takegami, Taisuke Seki, Yusuke Osawa, Shiro Imagama

Bone & joint research Vol. 11 ( 5 ) page： 270 - 277 2022.5

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：British Editorial Society of Bone {\&} Joint Surgery

AIMS: Periprosthetic hip fractures (PPFs) after total hip arthroplasty are difficult to treat. Therefore, it is important to identify modifiable risk factors such as stem selection to reduce the occurrence of PPFs. This study aimed to clarify differences in fracture torque, surface strain, and fracture type analysis between three different types of cemented stems. METHODS: We conducted biomechanical testing of bone analogues using six cemented stems of three different types: collarless polished tapered (CPT) stem, Versys Advocate (Versys) stem, and Charnley-Marcel-Kerboull (CMK) stem. Experienced surgeons implanted each of these types of stems into six bone analogues, and the analogues were compressed and internally rotated until failure. Torque to fracture and fracture type were recorded. We also measured surface strain distribution using triaxial rosettes. RESULTS: There was a significant difference in fracture torque between the three stem types (p = 0.036). Particularly, the median fracture torque for the CPT stem was significantly lower than that for the CMK stem (CPT vs CMK: 164.5 Nm vs 200.5 Nm; p = 0.046). The strain values for the CPT stem were higher than those for the other two stems at the most proximal site. The fracture pattern of the CPT and Versys stems was Vancouver type B, whereas that of the CMK stem was type C. CONCLUSION: Our study suggested that the cobalt-chromium alloy material, polished surface finish, acute-square proximal form, and the absence of a collar may be associated with lower fracture torque, which may be related to PPF. Cite this article: Bone Joint Res 2022;11(5):270-277.

DOI： 10.1302/2046-3758.115.BJR-2021-0375.R2

【整形外科画像診断・評価の進歩】人工知能(AI),深層学習人工知能を用いた骨折診断 Invited

佐藤洋一, 竹上靖彦

整形外科 Vol. 73 ( 6 ) page： 707 - 710 2022.5

Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(株)南江堂

＜文献概要＞はじめに人工知能(AI)は今や社会生活の一部となり欠かせないものとなっている.整形外科分野もその例外ではない.本稿では,骨折診断AIに関する文献のレビューを行い,現状の研究開発状況の整理,そして社会実装を含めた今後の展望を述べる.

Other Link： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2022&ichushi_jid=J00764&link_issn=&doc_id=20220527300040&doc_link_id=10.15106%2Fj_seikei73_707&url=https%3A%2F%2Fdoi.org%2F10.15106%2Fj_seikei73_707&type=%88%E3%8F%91.jp_%83I%81%5B%83%8B%83A%83N%83Z%83X&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

Displaced humeral head after intramedullary nailing for proximal humeral fracture is associated with worse short-term outcomes-a multicenter TRON study. Reviewed International journal Open Access

Yutaka Hiramatsu, Yasuhiko Takegami, Tokutake Katsuhiro, Yu Matsuura, Koichiro Makihara, Tokumi Kanemura, Shiro Imagama

JSES international Vol. 6 ( 3 ) page： 374 - 379 2022.5

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Background: In recent years, complex and unstable proximal humeral fractures (PHFs) are treated with intramedullary nails (IMNs) in the elderly; however, the postoperative radiographic findings related to the clinical outcome are not clear. This study evaluated the association of clinical outcomes with the radiographic findings of PHFs treated with IMNs. Methods: We collected data of patients aged >60 years with PHFs treated with IMNs from 2015 to 2019 in 13 associated centers' database (named TRON). We excluded patients lost to follow-up of <6 months postoperatively (PO6M). We evaluated clinical outcomes with the University of California at Los Angeles (UCLA) score at PO6M and defined a score of <27 as poor. We assessed the radiographic findings on the anteroposterior view of the humeral head postoperatively, and each radiographic finding such as humeral head height (HHH), head shaft angle, and cranialization of the greater tuberosity was divided into two groups: poor and good. Factors associated with poor UCLA at PO6M were extracted by logistic regression analysis, and the factors were divided into two groups (poor and good) and matched for age, sex, and fracture type. The UCLA score at PO6M between the groups was examined by the Mann-Whitney U test, and the significance level was set at 0.05. The minimal clinical important difference in the UCLA score was set 2 points. Results: The study included 243 patients (mean age, 76 years; range, 60-95 years). The mean follow-up period was 12 months (range, 6-56 months). The correlation coefficients indicated that there was either no or only a weak correlation between HHH, head shaft angle, and cranialization of the greater tuberosity. A poor HHH (HHH <0 or >10 mm) was extracted as a factor associated with a poor UCLA score at PO6M by logistic regression analysis (odds ratio: 5.78, 95% confidence interval = 1.2-27.7, P = .0287). In matched pair analysis, the UCLA score at PO6M was significantly lower in the poor HHH group (26 [range: 9-33] vs. 24 [range: 10-35], P = .0458). Conclusion: We revealed that the HHH was an independent risk factor for poor short-term outcomes. There was a significant difference in the UCLA score between groups divided by the HHH in cases treated with IMNs. The HHH can be used intraoperatively or postoperatively as a reliable parameter to predict clinical outcomes in PHFs treated with IMNs.

DOI： 10.1016/j.jseint.2021.12.009

Factors influencing inconsistent leg length discrepancy in dysplastic hip osteoarthritis: a retrospective study. Reviewed International journal Open Access

Genta Takemoto, Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Satoshi Ochiai, Daisaku Kato, Shiro Imagama

BMC musculoskeletal disorders Vol. 23 ( 1 ) page： 381 - 381 2022.4

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: We aimed to examine the inconsistency between radiographic leg length discrepancy (R-LLD) and perceived LLD (P-LLD) in patients with dysplastic hip osteoarthritis and to evaluate the factors that can cause such inconsistency. METHODS: We conducted a retrospective study on 120 patients. An inconsistent LLD was defined as a condition in which the P-LLD was shorter than the R-LLD by > 5 mm. We compared relevant data on the general characteristics of the patients and the radiological findings between consistent (group E, 92 cases [76.7%]) and inconsistent LLDs (group S, 28 cases [23.3%]). RESULTS: The number of patients with a history of hip surgery on the affected side and the Japanese Orthopedic Association classification pain scores were significantly higher in group S than in group E (32.1% vs. 10.8%, respectively; P = 0.015, and 21.7 ± 7.0 vs. 17.5 ± 8.2, respectively; P = 0.036). The pelvic oblique angle and length of the R-LLD were significantly higher in group S than in group E (2.9 ± 2.5° vs. 0.3 ± 2.3°, respectively; P < 0.01, and 17.2 ± 8.9 mm vs. 6.3 ± 8.4 mm, respectively; P < 0.01). Multivariate logistic analysis revealed that the pelvic oblique angle (odds ratio [OR]: 1.80, 95% confidence interval [CI]: 1.28-2.52; P < 0.01) and length of the R-LLD (OR: 2.75, 95% CI: 1.24-6.12; P = 0.013) were independent risk factors of inconsistent LLD. CONCLUSION: The pelvic oblique angle and a long R-LLD were independent risk factors of inconsistent LLD in patients with dysplastic hip osteoarthritis. Therefore, hip surgeons should consider P-LLD rather than R-LLD to understand the need for conservative intervention.

DOI： 10.1186/s12891-022-05348-z

Associations Between Neck and Shoulder Pain and Neuropathic Pain in a Middle-aged Community-living Population. Reviewed International journal

Masaaki Machino, Kei Ando, Kazuyoshi Kobayashi, Hiroaki Nakashima, Sadayuki Ito, Masayoshi Morozumi, Shunsuke Kanbara, Naoki Segi, Hiroyuki Tomita, Hiroyuki Koshimizu, Taisuke Seki, Shinya Ishizuka, Yasuhiko Takegami, Yukiharu Hasegawa, Shiro Imagama

Spine Vol. 47 ( 8 ) page： 632 - 639 2022.4

Language：English Publishing type：Research paper (scientific journal)

STUDY DESIGN: A cross-sectional study. OBJECTIVE: The present study aimed to investigate the prevalence of NeP in subjects suffering from NSP to reveal the impact of NeP on the health-related QOL (HRQOL) in middle-aged and elderly people with NSP in a health checkup. SUMMARY OF BACKGROUND DATA: No previous studies have established the relationship between NSP and NeP as potential risk factors contributing to a decreased QOL in the general population. METHODS: The present study involved 203 participants (men: 84, women: 119; mean age: 63.3 yr). For each subject, anthro-pometric measurements, physical function examinations, and blood testing were performed. A cut-off score of >0 on the short-form spine painDETECT questionnaire defined the presence of NeP. Subsequently, the NSP (+) subjects were divided into 2 sub-groups: the NeP (+) and NeP (-) groups. For the assessment of QOL, the short form 36 health survey and the EuroQol 5 dimension 5 level version (EQ-5D-5L) tool were used. RESULTS: The study included 100 NSP (+) and 103 NSP (-) subjects. Among the NSP (+) subjects, 46 and 54 subjects were found to be NeP (+) and NeP (-), respectively. For the short form 36 health survey, the multivariate regression analysis revealed that the prevalence of NeP was associated with a lower physical QOL (OR 3.56) and lower mental QOL (OR 4.04). Similarly, the NeP prevalence was found to be the predictor for low QOL scores in EQ-5D-5L (EQ-5D-5L index value <0.875; OR 3.61). CONCLUSION: The prevalence of NeP was reported to be 46.0% in healthy middle-aged and elderly population suffering from NSP, where it was associated with poor HRQOL. Therefore, strategies aimed at alleviating NeP may contribute significantly to the improvement of QOL in middle-aged and elderly people with NSP.Level of Evidence: 2.

DOI： 10.1097/BRS.0000000000004207

Risk factors for second hip fracture in elderly patients: an age, sex, and fracture type matched case-control study. Reviewed International journal

Tomoki Fujita, Yasuhiko Takegami, Kei Ando, Yasuomi Sakai, Hiroatsu Nakashima, Shiro Takatsu, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 32 ( 3 ) page： 437 - 442 2022.4

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Prevention of second hip fracture is mandatory for orthopedic surgeons. We aimed to clarify the incidence and duration of second hip fracture, to compare survival rate and walking ability of patients with a second hip fracture to that of patients with a unilateral fracture, and to identify risk factors for second hip fracture using matched case-control methods. METHODS: This retrospective study conducted in a single tertiary emergency center comprised 119 patients with second hip fractures who underwent bilateral operations at our institution from 2007 to 2017 (second hip fracture group [Group A]). The control group (Group B) comprised 357 patients matched to Group A for age, sex, and fracture type. RESULTS: The incidence of second hip fracture was 7.6%, and the average interval from initial fracture to second hip fracture was 22.8 months. Significantly more patients in Group A had decreased postoperative walking ability. Five-year survival rates from initial fracture were 65.0% in Group A and 50.6% in Group B (P = 0.346). Dementia and heart disease were identified as independent risk factors (dementia: HR 2.08, 95% CI 1.27-3.41, P = 0.004; heart disease: HR 1.27, 95% CI1.11-3.22, P = 0.019). Valvular disease was also revealed to be a risk factor for heart disease (P = 0.0272). CONCLUSIONS: The incidence of second hip fracture was not low. Although survival rates did not differ between the patients with or without second hip fracture, walking ability of patients with second hip fracture worsened. Dementia and cardiac disease could be risk factors for second hip fracture in elderly patients, and valvular disease might be associated with second hip fracture in patients with heart disease.

DOI： 10.1007/s00590-021-02996-0

Predictive factors for mortality after distal femoral fractures in the elderly: A retrospective multicenter (TRON group) study. Reviewed International journal Open Access

Yotaro Yamada, Yasuhiko Takegami, Katsuhiro Tokutake, Katsuhiro Taguchi, Yutaro Kuwahara, Kentaro Komaki, Shiro Imagama

Injury Vol. 53 ( 3 ) page： 1225 - 1230 2022.3

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: This retrospective multicenter study aimed to assess the 1-year mortality rate in elderly patients with distal femoral fractures (DFFs) and identify potential risk factors for mortality. METHODS: We analyzed 321 patients aged 65 years and older with DFFs treated surgically between 2012 and 2019 in 13 hospitals. Patient demographics and surgical characteristics were extracted from medical records and radiographs. We used univariable and multivariable Cox regression analyses to identify the factors affecting mortality. RESULTS: The mortality rate for DFFs in elderly patients at 1 year was 9.0%. Multivariable Cox regression analysis revealed older age, male sex, underweight (body mass index [BMI] <18.5 kg/m2), bedridden status, and nursing home residency to be independent predictors for mortality (older age: hazard ratio [HR] 1.07, 95% confidence interval [CI] 1.03-1.11, P<0.001; male sex: HR 3.08, 95% CI 1.23-7.71, P=0.015; underweight: HR 1.93, 95% CI 1.01-3.68, P=0.045; bedridden status: HR 4.59, 95% CI 1.61-13.07, P=0.0042; and nursing home residency: HR 2.63, 95% CI 1.18-5.83, P=0.017). None of the factors associated with surgery including types of fixation, time from initial visit to surgery, blood loss during operation, and operation time was an independent predictor for mortality. CONCLUSION: The 1-year mortality rate in elderly patients with DFFs was relatively low at 9.0%. Older age, lower BMI, and nursing home residency were associated with mortality after surgery for DFFs. Factors associated with the surgical procedure were not significant predictors.

DOI： 10.1016/j.injury.2022.01.002

高齢者の橈骨遠位端骨折プレート固定術後の早期運動開始群と短期間固定群の比較多施設共同研究(TRONStudy) Reviewed

斎藤雄馬, 竹上靖彦, 徳武克浩, 柴田隆太郎, 森悠祐, 櫻井咲, 松原浩之, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 3 ) page： S656 - S656 2022.3

大腿骨遠位部骨折の逆行性髄内釘固定術後において、荷重時期は術後成績に影響するか多施設共同研究 TRON study Reviewed

小牧健太郎, 竹上靖彦, 徳武克浩, 花林雅裕, 桑原悠太郎, 山田陽太郎, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 3 ) page： S1028 - S1028 2022.3

尺骨肘頭骨折の観血的骨接合術時の尺骨神経剥離術併用の効果多施設共同研究(TRON study) Reviewed

水野健, 竹上靖彦, 徳武克浩, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 2 ) page： S252 - S252 2022.3

肘頭骨折に対するtension band wiring法において、鋼線の設置位置(wire position)が臨床成績に与える影響多施設共同研究 Reviewed

金子怜奈, 平松泰, 竹上靖彦, 徳武克浩, 小澤英史, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 3 ) page： S642 - S642 2022.3

踵骨骨折の側方伸展アプローチによるプレート固定と足根洞アプローチによる中空裸子固定の比較検討多施設共同後ろ向き研究 Reviewed

杉本拓也, 徳武克浩, 竹上靖彦, 鏡味佑志朗, 杉本遼介, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 3 ) page： S857 - S857 2022.3

髄内釘を用いて手術を施行した上腕骨近位端骨折の臨床成績不良と関連するX線画像所見多施設共同研究(TRON study) Reviewed

平松泰, 竹上靖彦, 徳武克浩, 松浦唯, 牧原康一郎, 金村徳相, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 3 ) page： S1017 - S1017 2022.3

高齢女性の橈骨遠位端骨折に伴う尺骨遠位端骨折に対する治療法の比較多施設(TRONグループ)によるレトロスペクティブ研究 Reviewed

柴田隆太郎, 竹上靖彦, 徳武克浩, 夏目唯弘, 松原祐二, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 3 ) page： S1153 - S1153 2022.3

高齢者の不安定な橈骨遠位端骨折の掌側ロッキングプレート固定における人工骨移植の効果 TRON study Reviewed

森悠祐, 竹上靖彦, 徳武克浩, 岡義春, 斎藤雄馬, 櫻井咲, 柴田隆太郎, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 3 ) page： S861 - S861 2022.3

多施設共同研究による高齢者の大腿骨遠位端骨折後の生命予後に関わる因子の検討 TRON study Reviewed

山田陽太郎, 竹上靖彦, 徳武克浩, 小牧健太郎, 桑原悠太郎, 田口勝啓, 今釜史郎

日本整形外科学会雑誌 Vol. 96 ( 3 ) page： S702 - S702 2022.3

DNA methylation is associated with muscle loss in community-dwelling older men -the Yakumo study- : a preliminary experimental study. Reviewed

Daisaku Kato, Yasuhiko Takegami, Taisuke Seki, Hiroaki Nakashima, Yusuke Osawa, Koji Suzuki, Hiroya Yamada, Yukiharu Hasegawa, Shiro Imagama

Nagoya journal of medical science Vol. 84 ( 1 ) page： 60 - 68 2022.2

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Frailty is a state of reduced muscle strength and activity in older people. DNA methylation is associated with osteoporosis and muscle loss in murine and other animal studies, but there are no epidemiological studies in humans. This study aimed to assess the association of osteoporosis and muscle loss with DNA methylation in community-dwelling older people. This cross-sectional study was performed in a rural part of Japan. We analyzed 204 subjects (98 men and 106 women). In univariate analysis, the two groups were compared according to the presence or absence of osteoporosis and of muscle loss. Logistic regression analysis was performed to determine predictors of frailty in the muscle loss group. We used age, sex, body mass index, smoking history, drinking history, serum albumin and C-reactive protein levels, diabetes, hypertension, hyperlipidemia, heart disease history, and LINE-1 DNA methylation as the factors. Probability values < 0.05 were considered to be statistically significant. The levels of LINE-1 DNA methylation in leukocytes were associated with muscle loss in men over the age of 60. LINE-1 DNA methylation levels were not associated with bone mineral density in either the men or women over the age of 60. LINE-1 DNA methylation levels in leukocytes correlated significantly with the risk of frailty in men over the age of 60. Promoting an understanding of DNA methylation may lead to a better understanding of the pathophysiology of muscle loss.

DOI： 10.18999/nagjms.84.1.60

Nutritional Influences on Locomotive Syndrome. Reviewed International journal Open Access

Sadayuki Ito, Hiroaki Nakashima, Kei Ando, Masaaki Machino, Taisuke Seki, Shinya Ishizuka, Yasuhiko Takegami, Kenji Wakai, Yukiharu Hasegawa, Shiro Imagama

Journal of clinical medicine Vol. 11 ( 3 ) 2022.2

Language：English Publishing type：Research paper (scientific journal)

Healthy dietary habits are important to prevent locomotive syndrome (LS). We investigated the relationship between LS and nutritional intake using community health checkup data. We included 368 participants who underwent LS staging, blood sampling, and nutritional intake assessments. Participants (163 adults < 65: 205 older adults ≥ 65) were divided into normal (N; LS stage 0) and LS (L; LS stage 1-2) groups, and blood sample data and nutritional intake were compared between groups. Among adults (N group, 71; L group, 92), low-density lipoprotein cholesterol (LDL-C) was significantly lower, and Vitamin B1 intake was significantly higher in the L than in the N group; LDL-C, p = 0.033; Vitamin B1, 0.029. Among older adults (N group, 85; L group, 120), hemoglobin (Hb), albumin, and calcium levels were significantly lower, and sodium, monounsaturated fatty acids (MUFA), and n-6 polyunsaturated fatty acids (n-6 PUFA) were significantly higher in the L than the N group; Hb, p = 0.036; albumin, 0.030; calcium, 0.025; sodium; 0.029; MUFA; 0.047, n-6 PUFA; 0.0233). Logistic regression analysis indicated that sodium was the risk factor for the L group (exp (B) 1.001, 95% CI: 1-1.001, p = 0.032). In conclusion, salt intake was associated with LS.

DOI： 10.3390/jcm11030610

How does intraoperative fracture malalignment affect postoperative function and bone healing following distal femoral fracture? : a retrospective multicentre study. Reviewed International journal Open Access

Yutaro Kuwahara, Yasuhiko Takegami, Katsuhiro Tokutake, Yotaro Yamada, Kentaro Komaki, Tsunenobu Ichikawa, Shiro Imagama

Bone & joint open Vol. 3 ( 2 ) page： 165 - 172 2022.2

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

AIMS: Postoperative malalignment of the femur is one of the main complications in distal femur fractures. Few papers have investigated the impact of intraoperative malalignment on postoperative function and bone healing outcomes. The aim of this study was to investigate how intraoperative fracture malalignment affects postoperative bone healing and functional outcomes. METHODS: In total, 140 patients were retrospectively identified from data obtained from a database of hospitals participating in a trauma research group. We divided them into two groups according to coronal plane malalignment of more than 5°: 108 had satisfactory fracture alignment (< 5°, group S), and 32 had unsatisfactory alignment (> 5°, group U). Patient characteristics and injury-related factors were recorded. We compared the rates of nonunion, implant failure, and reoperation as healing outcomes and Knee Society Score (KSS) at three, six, and 12 months as functional outcomes. We also performed a sub-analysis to assess the effect of fracture malalignment by plates and nails on postoperative outcomes. RESULTS: The rates of nonunion and reoperation in group U were worse than those in group S (25.0% vs 14.3%; 15.6% vs 5.6%), but the differences were not significant (p = 0.180 and p = 0.126, respectively). Mean KSS in group U at all follow-up periods was significantly worse that in group S (75.7 (SD 18.8) vs 86.0 (SD 8.7); p < 0.001; 78.9 (SD 17.2) vs 89.1 (SD 9.8); p < 0.001; 85.0 (SD 11.9) vs 91.1 (SD 7.2); p = 0.002, respectively). In the sub-analysis of plates, mean KSS was significantly worse in group U at three and six months. In the sub-analysis of nails, the rate of reoperation was significantly higher in group U (28.6% vs 5.8%; p = 0.025), and mean KSS at six and 12 months was significantly worse in Group U. CONCLUSION: To obtain good postoperative functional results, intraoperative alignment of the coronal plane should be accurately restored to less than 5°. Cite this article: Bone Jt Open 2022;3(2):165-172.

DOI： 10.1302/2633-1462.32.BJO-2021-0191.R1

The development of knee osteoarthritis and serum carotenoid levels among community-dwelling people in Japan Reviewed International journal

Genta Takemoto, Taisuke Seki, Yasuhiko Takegami, Yusuke Osawa, Kazuya Makida, Satoshi Ochiai, Shinya Ishizuka, Koji Suzuki, Yukiharu Hasegawa, Shiro Imagama

Modern Rheumatology Vol. 32 ( 1 ) page： 205 - 212 2022.1

Language：English Publishing type：Research paper (scientific journal)

Objectives: Carotenoids are plant pigments found in many vegetables, functioning as antioxidants scavenging singlet molecular oxygen and peroxyl radicals. No longitudinal study exists on the relationship between carotenoids and knee osteoarthritis (KOA) development. We aimed to determine the incidence of KOA development for 10 years in community-dwelling people in Japan and assess its association with serum carotenoids. Methods: Data of 440 participants (174 men, 266 women) with health-screening records for at least 10 years were analysed. We defined KOA development as advancing from K/L grade 0/1 at the initial check-up to grade ≥2 in a unilateral knee during a 10-year follow-up period. Serum carotenoid levels were measured using high-performance liquid chromatography. We used the Cox hazard model for multivariate analysis and investigated each carotenoid’s impact on KOA development. Results: KOA developed in 33.4% of patients; the annual KOA development rate was significantly higher among women than among men (p <.01; 3.4% vs. 1.6%). Among the carotenoids measured, only retinol was associated with KOA development in women using multivariable analysis. KOA development was not associated with any carotenoids in men. Conclusion: The annual rate of KOA development was higher in women, and retinol was associated with KOA development in women.

DOI： 10.1080/14397595.2021.1900030

Effects of additional neck cut of the femur on the range of motion in total hip arthroplasty for hip dislocation: a computer simulation study. Reviewed International journal

Kazuya Makida, Taisuke Seki, Yusuke Osawa, Yasuhiko Takegami, Yoshitoshi Higuchi, Taiki Kusano, Naoki Ishiguro

Hip international : the journal of clinical and experimental research on hip pathology and therapy Vol. 32 ( 1 ) page： 39 - 44 2022.1

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Subtrochanteric shortening osteotomy (SSO) is commonly performed in total hip arthroplasty (THA) for high hip dislocation. However, this procedure is technically difficult and includes complications. Additional neck cut (ANC) of the femur is a procedure that involves femoral shortening by possibly eliminating the need for SSO in THA for high hip dislocation. Herein, we evaluated the effect and the depth limit of ANC of the femur on the range of motion (ROM) in THA for high hip dislocation. METHODS: ROM was measured in 26 patients with high hip dislocation using computer software. The stem was deeply positioned at 5-mm intervals from 0 mm to 30 mm (7 groups). The ROM before impingement was measured during flexion, internal rotation (IR) at 90° flexion, external rotation (ER) and abduction. Receiver operator coefficient (ROC) curves for abduction were generated. The cut-off value of ANC where the required ROM was achieved was also determined. RESULTS: Deeper ANCs increased the ROM values during flexion and IR, but they decreased the ROM values during ER and abduction. The ROM values during ER were also limited in 0-mm ANCs. According to the result of the ROC curve for abduction, 15 mm was considered as the permissible range of ANC. CONCLUSIONS: In THA for high hip dislocation additional neck cut should be taken into consideration for hips requiring less than 15-mm shortening. For more extended corrections a subtrochanteric shortening osteotomy should be performed.

DOI： 10.1177/1120700020938657

Prediction of delayed union of tibial shaft fracture treated with intramedullary nailing: multicenter-study analysis and literature review -the TRON study. Reviewed International journal

Narumi Kawasaki, Yasuhiko Takegami, Risa Sakai, Kazunori Todoroki, Ryota Uemi, Shiro Imagama

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 32 ( 1 ) page： 129 - 135 2022.1

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media {LLC}

PURPOSE: We aimed to 1) identify predictors of delayed and nonunion of tibial shaft fractures in patients treated with intramedullary nailing (IMN), including patient demographics and surgical factors, and 2) determine whether the nail/shaft ratio is associated with delayed and nonunion. METHODS: This retrospective, multicenter study included 315 patients with tibial shaft fracture treated with IMN between 2014 and 2019 and excluded patients with insufficient follow-up for 12 months, lost data and inadequate radiographs. Finally, we analyzed 258 patients (184 males; 74 females). Main outcome measurements were delayed union at 6 and nonunion at 12 months after surgery as determined on anteroposterior and lateral radiographs. We extracted the following as risk factors of delayed and nonunion: age, sex, BMI, fracture site, fracture type, injury energy, smoking history, and nail/shaft ratio. We conducted logistic regression analysis to investigate risk factors of delayed and nonunion using these extracted items as explanatory variables. RESULTS: Type C fracture was independently associated with delayed union (odds ratio 2.9, 95% confidential interval: 1.04-8.09, P = 0.04). Nail/shaft ratio was not an independent factor of delayed union. No independent explanatory factors were related to nonunion. CONCLUSIONS: Type C fractures, which were unstable and fragmented, was associated with delayed union in tibia fractures treated with IMN, whereas nail thickness was not associated with delayed or nonunion fractures.

DOI： 10.1007/s00590-021-02939-9

Collapse Progression or Cessation Affects the Natural History of Contralateral Osteonecrosis of the Femoral Head. Reviewed International journal

Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Kazuya Makida, Satoshi Ochiai, Shiro Imagama

The Journal of arthroplasty Vol. 36 ( 12 ) page： 3839 - 3844 2021.12

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: It is unclear how the condition of one side of the hip joint affects the natural history of contralateral osteonecrosis of the femoral head (ONFH). This study aimed to investigate the natural progression of bilateral ONFH on the asymptomatic side between patients with collapse progression and cessation on the symptomatic side. METHODS: The study included 109 patients with bilateral ONFH at the first visit, who were divided into two groups in accordance with the symptomatic side based on the collapse progression of ≥3 mm (progressive group: 74 hips) and collapse cessation of <3 mm (stable group: 35 hips) with a minimum follow-up of 3 years. The assessment parameters included age, gender, body mass index, etiology, type classification, and survival rates of the asymptomatic side with radiographic failure as the endpoints. RESULTS: Age, gender, body mass index, and etiology were not different between the two groups; however, a difference was observed in the type classification of the symptomatic side. The 4-year survival rates were significantly different between the progressive (34.3%) and stable groups (85.7%). Multivariate Cox regression analysis showed that age <40 years (vs ≥40 years; hazard ratio [HR], 2.439), type C2 (vs B + C1; HR, 2.865), and collapse progression on the symptomatic side (vs collapse cessation; HR, 7.751) were independent factors determining collapse on the asymptomatic side. CONCLUSION: Collapse progression on the symptomatic side is a poor prognostic factor for the natural history of contralateral ONFH.

DOI： 10.1016/j.arth.2021.08.005

神経ブロックを併用した人工股関節置換術後に腓骨神経麻痺を呈し診断に苦慮した1例 Reviewed

絹川友章, 田村高廣, 竹上靖彦, 関泰輔, 西脇公俊

日本ペインクリニック学会誌 Vol. 28 ( 9 ) page： 194 - 198 2021.9

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(一社)日本ペインクリニック学会

【症例】46歳女性,身長157cm,体重58kg.20歳ごろより両股関節痛を生じ,変形性関節症と診断され保存的に加療していた.当院整形外科紹介受診し,左人工股関節置換術施行予定となった.腰神経叢ブロックと傍仙骨部の坐骨神経ブロックを施行後,全身麻酔導入し,手術を行った.術後のレントゲンで脚延長は20mmであった.覚醒後,両下肢に運動障害と感覚障害があった.症状は数時間以内に改善し,腰神経叢ブロックが硬膜外ブロックになったと考えられ,画像検査で血種による神経圧迫などを除外した上で経過観察となった.その後,感覚障害と運動障害は改善傾向であったが左足関節の背屈運動のみ回復が遅れ,術28日後の筋電図検査にて腓骨頭レベルでの軽度腓骨神経障害と診断された.術32日後,杖歩行安定し退院した.【まとめ】本症例の神経症状は,腓骨頭レベルでの神経障害であることから,腓骨神経の過伸展等の物理的因子に起因することが推察されるが,腰神経叢ブロックが硬膜外ブロックになったことにより麻痺症状が初期段階ではマスクされた.また今回の神経ブロックが麻痺に影響した可能性も否定できない.(著者抄録)

Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2021&ichushi_jid=J03612&link_issn=&doc_id=20210928360003&doc_link_id=10.11321%2Fjjspc.21-0029&url=https%3A%2F%2Fdoi.org%2F10.11321%2Fjjspc.21-0029&type=J-STAGE&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00007_3.gif

The association of the progression of knee osteoarthritis with high-sensitivity CRP in community-dwelling people-the Yakumo study. Reviewed International journal

Fumiki Kondo, Yasuhiko Takegami, Shinya Ishizuka, Yukiharu Hasegawa, Shiro Imagama

Clinical rheumatology Vol. 40 ( 7 ) page： 2643 - 2649 2021.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media {LLC}

OBJECTIVE: We aimed to investigate the relationship between high-sensitivity CRP (hs-CRP) levels and the knee osteoarthritis (KOA) status and whether high hs-CRP levels predict the progression of clinical KOA in community-dwelling people. METHODS: We enrolled 247 subjects (male, n = 99; female, n = 148) who participated in the "Yakumo study" at least twice from 2003 to 2008. The KOA was evaluated by knee X-ray using the knee osteoarthritis computer-aided diagnosis (KOACAD) measurement system to obtain the mJSW, the size of the osteophyte area (OPA), and femorotibial angle (FTA). The pain intensity of the knee joint was measured using a visual analog scale (VAS, 0-100). First, we performed a multiple regression analysis to assess the relationship between the initial hs-CRP and mJSW, OPA, FTA, and VAS. Second, we examined the correlated coefficients between the amount of change hs-CRP and radiographic progressions and VAS changes. Third, we divided into two groups. Group H elevated hs-CRP levels (> 0.1 mg/dl). We picked up the subject matched to Group H according to BMI, age, sex, and medial mJSW at baseline in a 1:1 ratio; these participants were classified as the control group (Group L). The Mann-Whitney U test was used to compare the demographic data between the two groups. P values of < 0.05 were considered to indicate statistical significance. RESULTS: The initial hs-CRP was a significant explanatory factor for mJSW and VAS change in multiple regression analysis. The change of VAS value negatively correlated with the change of hs-CRP. Besides, the change of hs-CRP did not correlate with the radiographical change. Among these subjects, 55 had elevated hs-CRP levels (> 0.1 mg/dl) (Group H). Among the 192 subjects whose hs-CRP levels were ≤ 0.1 mg/dl, 55 subjects were matched to patients in Group H according to the age, sex, BMI, and average minimum joint space width (mJSW) at baseline and were used as a control group (Group L). The narrowing of the medial mJSW and the amount of change in OPA in group H were significantly greater than group L. The amount of change in FTA and VAS scores did not differ between the two groups. CONCLUSION: Hs-CRP levels would be significantly associated with the progression of knee osteoarthritis. Key Points • We investigated the relationship between hs-CRP levels and the progression and the pain of osteoarthritis knee. • We used a KOACAD system, which can measure the medial and lateral joint space narrowing, osteophyte, and femoral-tibia angle from plain radiographs automatically. • Hs-CRP levels were significantly associated with the progression of knee osteoarthritis.

DOI： 10.1007/s10067-020-05541-2

Smoking and trimalleolar fractures are risk factors for infection after open reduction and internal fixation of closed ankle fractures: A multicenter retrospective study of 1,201 fractures. Reviewed International journal

Toshifumi Sato, Yasuhiko Takegami, Takayuki Sugino, Kosuke Bando, Tomoki Fujita, Shiro Imagama

Injury Vol. 52 ( 7 ) page： 1959 - 1963 2021.7

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: One of the complications of the surgical therapy for ankle fractures includes wound infection. This study aimed to evaluate postoperative function and clarify the risk factors associated with postoperative wound infection in patients receiving the open reduction and internal fixation for ankle fracture through a multicenter study. SUBJECTS AND METHOD: Among 1421 patients diagnosed as having closed ankle fracture and who were treated by surgical therapy in 11 institutions from 2014 through 2019, 1201 patients (men, n = 512, women, n = 689; the mean (SD) age, 50.9 (15.6) years; the mean body mass index [BMI] (SD), 24.3 (4.2) kg/m2) were included as subjects. Excluded were 220 patients due to self-termination of treatment, inability to follow up after discharge, open fracture, distal tibia shaft fracture, and pilon fracture. We extracted the following as risk factors of wound infection: age, sex, BMI, fracture type, injury energy and histories of smoking, diabetes, arteriosclerosis, heart failure and myocardial infarction. We conducted logistic regression analysis to investigate the risk factors of wound infection using these extracted items as explanatory variables and the presence or absence of wound infection as the response variable. RESULTS: Wound infection occurred after surgery for closed ankle fracture in 69 the 1201 patients (5.7%). The causative organism was methicillin-susceptible Staphylococcus aureus (MSSA) in 15 patients, methicillin-resistant S. aureus (MRSA) in 4 patients, Finegoldia magna in one patient, and S. haemolyticus in one patient. In the other patients, causative organisms were not detected, culture of the causative organisms was not conducted, or they were unknown. The univariate analysis showed significant differences in sex (p = 0.01) and for smoking (p = 0.002), fracture type (p = 0.02) and heart failure (p = 0.042). Logistic regression analysis showed that smoking and type of fracture (trimalleolar fracture) were significant explanatory factors for infection (odds ratio 1.83 and 1.98, p = 0 .040 and 0.042, respectively). CONCLUSIONS: At 5.7%, the rate of postoperative wound infection in closed ankle fracture was not low. Staphylococcus was the most frequent causative organism. The surgeon should pay attention infection after surgery in the patients who had a trimalleolar fracture or smoking habits.

DOI： 10.1016/j.injury.2021.04.017

不安定型脆弱性骨盤骨折における手術加療は早期離床を促し生存率や術後臨床機能を改善させるか Reviewed

齊藤祐樹, 徳武克浩, 竹上靖彦

骨折 Vol. 43 ( Suppl. ) page： S193 - S193 2021.7

Impact of Neck and Shoulder Pain on Health-Related Quality of Life in a Middle-Aged Community-Living Population. Reviewed International journal Open Access

Masaaki Machino, Kei Ando, Kazuyoshi Kobayashi, Hiroaki Nakashima, Masayoshi Morozumi, Shunsuke Kanbara, Sadayuki Ito, Taro Inoue, Hiroyuki Koshimizu, Taisuke Seki, Shinya Ishizuka, Yasuhiko Takegami, Yukiharu Hasegawa, Shiro Imagama

BioMed research international Vol. 2021 page： 6674264 - 6674264 2021.6

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Neck and shoulder pain (NSP) is very common in the general population. However, scarce information exists on the relationship between NSP and health-related quality of life (HRQOL) outcomes in this population. The present study described NSP prevalence and its impact on the HRQOL of middle-aged and older persons undergoing a routine medical checkup. METHODS: This study recruited 318 subjects (125 males and 193 females; average age, 63.4 years) in good health, collected underwent anthropometric measurements, physical function examinations, and blood testing. This study defined NSP as the presence of muscle tension, stiffness, pressure, or dull pain in areas between the neck and the arch of the scapular. Study subjects were divided into two groups (NSP (+) and NSP (-) groups). The subjects completed questions on the Medical Outcomes Study 36-item short-form health survey (SF-36) and the EuroQol 5-dimension, 5-level version (EQ-5D-5L) tool. RESULTS: Of the patients, 150 and 168 were NSP (+) and NSP (-), respectively. The NSP complaint rate was 47.2%. The NSP (+) group had younger and more female participants than the NSP (-) group. In the multivariate regression analysis, the NSP (+) group had lower physical QOL based on the SF-36 physical component summary (odds ratio (OR), 2.45) and lower mental QOL based on the SF-36 mental component summary (OR, 2.05). Overall, the NSP (+) group had a higher risk of having low QOL scores (EQ-5D-5L index; OR, 1.76). CONCLUSIONS: The NSP (+) rate in healthy middle-aged and older persons was 47.2%. Furthermore, NSP (+) status was directly related poor HRQOL. NSP is a predictor of suboptimal physical and mental QOL. Therefore, NSP prevention or intervention for NSP may improve middle-aged and older adults' QOL.

DOI： 10.1155/2021/6674264

Early versus delayed weight bearing after intramedullary nailing for tibial shaft fracture: A multicenter, propensity score-matched study, the TRON study. Reviewed International journal

Ryota Uemi, Yasuhiko Takegami, Risa Sakai, Kazunori Todoroki, Narumi Kawasaki, Shiro Imagama

Injury Vol. 52 ( 6 ) page： 1583 - 1586 2021.6

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

OBJECTIVES: The purpose of this multicenter study was to assess the differences in the rates of implant failure and bone union by X-ray examination, and walking ability between an early weight-bearing group (EWB) and a non-weight-bearing group (NWB) following treatment with intramedullary nailing (IMN) for tibial shaft fractures with a propensity score-matching method. MATERIAL AND METHODS: We collected data from 336 patients with tibia fractures that were treated surgically. We excluded patients lost to follow-up and polytrauma patients. Finally, 263 patients were included who were divided into two groups, the early weight-bearing (EWB) group, in which partial weight-bearing walking within four weeks was encouraged, and a non-weight-bearing (NWB) group, in which no weight bearing was allowed for more than four weeks. To adjust for baseline differences between groups, a propensity score algorithm was used to match the EWB group with the NWB group in a 1:1 ratio of 75 cases each. After matching, we compared the rate of implant failure, the rate of bone union at six months and one year after surgery, and walking ability at the last follow-up between the two groups. RESULT: Implant failure occurred in 0 of 75 patients in the EWB group vs. 1 of 75 in the NWB group (P = 1.0). Delayed bone union at six months occurred in 20 of 75 (26%) vs. 13 of 75 (17%) patients, and that at one year occurred in 5 of 75 (6.7%) vs. 3 of 75 (4%) patients. The median New Mobility Score was 9 (4-9) vs. 9 (0-9) points. CONCLUSIONS: There were no statistically significant differences in the rate of implant failure, the rates of the bone union at six months and one year after surgery, and walking ability between the EWB group and NWB group. We suggest that instruction in early weight-bearing after IMN nailing for tibial shaft fracture may not be harmful.

DOI： 10.1016/j.injury.2020.12.023

Artificial intelligence improves the accuracy of residents in the diagnosis of hip fractures: a multicenter study. Reviewed International journal Open Access

Yoichi Sato, Yasuhiko Takegami, Takamune Asamoto, Yutaro Ono, Tsugeno Hidetoshi, Ryosuke Goto, Akira Kitamura, Seiwa Honda

BMC musculoskeletal disorders Vol. 22 ( 1 ) page： 407 - 407 2021.5

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Less experienced clinicians sometimes make misdiagnosis of hip fractures. We developed computer-aided diagnosis (CAD) system for hip fractures on plain X-rays using a deep learning model trained on a large dataset. In this study, we examined whether the accuracy of the diagnosis of hip fracture of the residents could be improved by using this system. METHODS: A deep convolutional neural network approach was used for machine learning. Pytorch 1.3 and Fast.ai 1.0 were applied as frameworks, and an EfficientNet-B4 model (a pre-trained ImageNet model) was used. We handled the 5295 X-rays from the patients with femoral neck fracture or femoral trochanteric fracture from 2009 to 2019. We excluded cases in which the bilateral hips were not included within an image range, and cases of femoral shaft fracture and periprosthetic fracture. Finally, we included 5242 AP pelvic X-rays from 4851 cases. We divided these 5242 images into two images per image, and prepared 5242 images including fracture site and 5242 images without fracture site. Thus, a total of 10,484 images were used for machine learning. The accuracy, sensitivity, specificity, F-value, and area under the curve (AUC) were assessed. Gradient-weighted class activation mapping (Grad-CAM) was used to conceptualize the basis for the diagnosis of the fracture by the deep learning algorithm. Secondly, we conducted a controlled experiment with clinicians. Thirty-one residents;young doctors within 2 years of graduation from medical school who rotate through various specialties, were tested using 300 hip fracture images that were randomly extracted from the dataset. We evaluated the diagnostic accuracy with and without the use of the CAD system for each of the 300 images. RESULTS: The accuracy, sensitivity, specificity, F-value, and AUC were 96.1, 95.2, 96.9%, 0.961, and 0.99, respectively, with the correct diagnostic basis generated by Grad-CAM. In the controlled experiment, the diagnostic accuracy of the residents significantly improved when they used the CAD system. CONCLUSIONS: We developed a newly CAD system with a deep learning algorithm from a relatively large dataset from multiple institutions. Our system achieved high diagnostic performance. Our system improved the diagnostic accuracy of residents for hip fractures. LEVEL OF EVIDENCE: Level III, Foundational evidence, before-after study. CLINICAL RELEVANCE: high.

DOI： 10.1186/s12891-021-04260-2

Arterial embolism due to massive cement leakage during total hip arthroplasty revision. Reviewed

Yusuke Kazama, Yasuhiko Takegami, Yusuke Osawa, Kazuya Makida, Taisuke Seki

Nagoya journal of medical science Vol. 83 ( 2 ) page： 353 - 359 2021.5

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

Total hip arthroplasty with cementing techniques leads to good clinical outcomes, but critical vascular complications can sometimes occur due to cement leakage into the pelvis. In this report, we describe a case of massive cement leakage that caused an arterial embolism. When exfoliating cement from an artery, the surgeon should note not only direct injury to the vessels but also the potential for arterial embolism.

DOI： 10.18999/nagjms.83.2.353

"いつの間にか骨折"をAI(人工知能)で胸部単純X線写真から診断する、陳旧性椎体骨折検出システムの開発研究多施設共同研究

佐藤洋一, 朝本学宗, 本田聖和, 鈴木朋浩, 三嶋真爾, 伊藤孝紀, 竹上靖彦

日本骨粗鬆症学会雑誌 Vol. 7 ( 2 ) page： 300 - 303 2021.5

Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：(一社)日本骨粗鬆症学会

一般に検診などで撮影頻度が高い胸部単純X線写真が撮影範囲に椎体骨折の好発部位である胸椎〜第2腰椎までを含むことに着目し、骨粗鬆症のスクリーニングに利活用する可能性について検討した。そしてこの診断時に、人工知能(AI)を用いて胸部単純X線写真における既存椎体骨折を検知する画像診断システムの開発を行った。胸部単純X線写真かつ胸椎〜腰椎レベルを含むCTまたはMRIを撮影した65歳以上の患者1889例(男性558例、女性1331例、平均77.4歳)を対象とした。内部データセットにおける機械精度では、蒲郡市民病院から得られたデータセットにより訓練された学習モデルのテスト画像に対する機械精度は診断精度92.1%、閾値0.69としたときの感度が95.8%、特異度が93.0%であった。また、外部データセットにおける機械精度では、蒲郡市民病院から得られたデータセットにより訓練された学習モデルの津島市民病院およびJCHO東京新宿メディカルセンターから得られたテスト画像に対する機械精度は診断精度71.3%であり、ROC曲線から算出されたAUCは0.78となった。既存椎体骨折をAIが検知する画像診断システムは、既存椎体骨折を有する骨粗鬆症患者のスクリーニングに有用な可能性があると考えられた。

Association between Low Muscle Mass and Inflammatory Cytokines. Reviewed International journal Open Access

Sadayuki Ito, Hiroaki Nakashima, Kei Ando, Kazuyoshi Kobayashi, Masaaki Machino, Taisuke Seki, Shinya Ishizuka, Ryosuke Fujii, Yasuhiko Takegami, Hiroya Yamada, Yoshitaka Ando, Koji Suzuki, Yukiharu Hasegawa, Shiro Imagama

BioMed research international Vol. 2021 page： 5572742 - 5572742 2021.4

Language：English Publishing type：Research paper (scientific journal)

Sarcopenia is a multifaceted geriatric syndrome associated with the loss of muscle mass. We examined the relationship between low muscle mass and inflammatory cytokines in the context of aging. This study involved 299 participants (127 men and 172 women; mean age 63.3 ± 9.8 years) who underwent health checkups for body composition and inflammatory cytokine (TNF-alpha, IL-6, and MCP-1) levels. Muscle mass was determined using the skeletal muscle mass index. We divided the participants into the normal (N) and low muscle mass (L) groups and compared the levels of inflammatory cytokines in nonelderly (<65 years) and elderly (≥65 years) participants. Among the nonelderly subjects, C-reactive protein was significantly lower in the L group than in the N group (p < 0.05). However, there was no significant difference in the inflammatory cytokine levels between the groups. Among the elderly subjects, the TNF-alpha level was significantly lower in the L group than in the N group (p < 0.05), whereas there were no significant differences in the IL-6 and MCP-1 levels. Moreover, TNF-alpha was identified as a risk factor for the L group in the logistic regression analysis (Exp (B) 0.935, 95% CI: 0.876-0.997, p = 0.04). Although a low TNF-alpha level is a risk factor for low muscle mass, inflammatory cytokine levels are not necessarily elevated in elderly individuals with the loss of muscle mass.

DOI： 10.1155/2021/5572742

Bioelectrical Impedance Analysis and Manual Measurements of Neck Circumference Are Interchangeable, and Declining Neck Circumference Is Related to Presarcopenia. Reviewed International journal Open Access

Masaaki Machino, Kei Ando, Kazuyoshi Kobayashi, Hiroaki Nakashima, Satoshi Tanaka, Shunsuke Kanbara, Sadayuki Ito, Taro Inoue, Hiroyuki Koshimizu, Taisuke Seki, Shinya Ishizuka, Yasuhiko Takegami, Yukiharu Hasegawa, Shiro Imagama

BioMed research international Vol. 2021 page： 6622398 - 6622398 2021.3

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: Preventive medicine is important in an aging society. Presarcopenia is the preliminary stage of sarcopenia. Recent advances in bioelectrical impedance analysis (BIA) devices have enabled automatic estimation of neck circumference (NC). However, the agreement between and interchangeability of NC measured manually and that calculated with BIA have not been evaluated. We performed these analyses in the context of health checkups and investigated their associations with presarcopenia. METHODS: We enrolled 318 participants who underwent anthropometric measurements, including NC measured manually and by BIA; assessment of physical function; and blood testing. We used Bland-Altman analysis to calculate the agreement between and interchangeability of NC measurements by BIA and by the manual method. We then statistically compared normal participants and those with presarcopenia. Using multivariable analysis, we subsequently investigated significant risk factors for presarcopenia. We defined presarcopenia according to the appendicular skeletal muscle index (aSMI; the ratio of arm and leg skeletal muscle mass to height2). RESULTS: Bland-Altman analysis showed that bias (BIA-manual) was negative overall (-1.07), for male participants (-1.23), and for female participants (-0.96). This finding suggests that BIA measurement is an underestimate in comparison with manual measurement. NC measurement by BIA was found to be interchangeable with that by manual methods, inasmuch as the percentage error was less than 5% overall (4.38%), for male participants (3.81%), and for female participants (4.58%). Univariable analysis revealed that NC was significantly smaller in the participants with presarcopenia than in those without. Multivariable analysis, adjusted for confounding factors, revealed that a decrease in NC was significantly correlated with presarcopenia. CONCLUSIONS: BIA measurements of NC are interchangeable within about 95% with manual measurements. The decrease in NC measured by BIA was significantly associated with presarcopenia in both genders. NC measurement can be used for early detection of presarcopenia.

DOI： 10.1155/2021/6622398

高齢者の脆弱性骨盤骨折(不安定型)の保存治療の検討 Reviewed

大道俊文, 竹上靖彦, 徳武克浩, 斉藤祐樹, 今釜史郎

中部日本整形外科災害外科学会雑誌 Vol. 64 ( 春季学会 ) page： 145 - 145 2021.3

脆弱性骨盤骨折不安定型における手術加療と保存加療での臨床成績の比較 Reviewed

斉藤祐樹, 竹上靖彦, 徳武克浩, 大道俊文, 今釜史郎

中部日本整形外科災害外科学会雑誌 Vol. 64 ( 春季学会 ) page： 145 - 145 2021.3

踵骨骨折手術においてBohler角を整復・維持することは重要である

杉本遼介, 竹上靖彦, 鏡味佑志朗, 杉本拓也, 徳武克浩, 今釜史郎

中部日本整形外科災害外科学会雑誌 Vol. 64 ( 春季学会 ) page： 106 - 106 2021.3

踵骨骨折術後の免荷装具は有効か? 多施設共同後ろ向き研究

鏡味佑志朗, 竹上靖彦, 徳武克浩, 杉本拓也, 杉本遼介, 今釜史郎

中部日本整形外科災害外科学会雑誌 Vol. 64 ( 春季学会 ) page： 106 - 106 2021.3

鎖骨遠位端骨折に対する固定材料による臨床成績の比較多施設共同後向き研究 Reviewed

高橋博司, 竹上靖彦, 片山雄二郎, 徳武克浩, 今釜史郎

中部日本整形外科災害外科学会雑誌 Vol. 64 ( 春季学会 ) page： 140 - 140 2021.3

Pelvic Tilt Reduces the Accuracy of Acetabular Component Placement When Using a Portable Navigation System: An In Vitro Study. Reviewed International journal Open Access

Hiroshi Asai, Yasuhiko Takegami, Taisuke Seki, Naoki Ishiguro

Arthroplasty today Vol. 7 page： 177 - 181 2021.2

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier {BV}

BACKGROUND: A portable navigation system (PNS) was recently introduced. The PNS enables surgeons to place the acetabular component accurately. While the margin of the error for the cup abduction and anteversion was larger than the values obtained from a computed tomography-based navigation system. We hypothesized that the accuracy of the PNS might be affected by pelvic tilt. MATERIAL AND METHODS: A bone substitute model of the pelvis was used in this in vitro study. We set the acetabular component using PNS. We set the acetabular component angle after changing the sagittal, coronal, and axial pelvic tilt. We calculated the difference between the angle displayed on the PNS display and the actual angle of the acetabular component. The difference in inclination angle was defined as ΔRI, and the difference in the anteversion angle was defined as ΔRA. We evaluated the trends in this ΔRI and ΔRA due to the pelvic tilt. RESULTS: In this in vitro study, the placement of the acetabular component was accurate in the neutral position; ΔRI was 0.5 ± 0.7° and ΔRA was 1.0 ± 0.7°. Sagittal pelvic tilt and axial pelvic tilt increased both the ΔRA and ΔRI (P = .017). Coronal tilt increased ΔRI but did not change ΔRA. CONCLUSIONS: While the PNS may enable surgeons to place accurate component placement in the neutral position, its accuracy decreased by pelvic tilt. The surgeons should use a solid pelvic lateral positioner for reducing discrepancies in pelvic tilt when using the PNS in the lateral decubitus position.

DOI： 10.1016/j.artd.2020.12.012

Does unilateral total hip arthroplasty improve pain and function in the non-operative hip joint? Reviewed International journal

Yasuhiko Takegami, Taisuke Seki, Yusuke Osawa, Taiki Kusano, Kazuya Makida, Naoki Ishiguro

European journal of orthopaedic surgery & traumatology : orthopedie traumatologie Vol. 30 ( 8 ) page： 1411 - 1416 2020.12

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media {LLC}

BACKGROUND: Some reports suggested that the status of the opposite-side hip affects clinical outcomes of unilateral total hip arthroplasty (THA) for hip osteoarthritis (HOA). This study aimed to determine whether unilateral THA could improve pain and movement of the non-operative hip. METHODS: The analysis included 195 patients divided into three groups according to contralateral hip status based on radiographic change assessed by Kellgren-Lawrence (KL) grade: normal hip (Group N: n = 124), HOA with KL grade > 2 (Group O: n = 39), and THA patients who already underwent THA in their opposite hip joint (Group T: n = 32). All patients were interviewed and examined preoperatively and at 1-year intervals after surgery. Hip function was evaluated with Harris Hip Score (HHS) and range of motion (ROM) preoperatively and at 1-year follow-up. We used the Japanese Orthopedic Association Hip-Disease Evaluation Questionnaire (JHEQ) and the Visual Analogue Scale (VAS) for separately evaluated right and left hip joints. RESULTS: The mJHEQ movement, which indicated the activity, and flexion of ROM in the non-operative hip improved in group N and group T. The VAS and JHEQ pain values did not differ between preoperative and 1-year follow-up in all groups. In the operative side, HHS function, JHEQ movement values in group O were significantly lower than those of groups N and T at 1-year follow-up. CONCLUSION: Unilateral THA may improve non-operative hip movement and active daily life except when the non-operated hip shows osteoarthritis. It did not improve non-operative hip pain, regardless of the condition on the other side. Clinical outcomes of unilateral THA may be affected by opposite hip status each other.

DOI： 10.1007/s00590-020-02716-0

Effect of periosteal resection on longitudinal bone growth in a mouse model of achondroplasia. Reviewed International journal Open Access

Shinya Kaneko, Masaki Matsushita, Kenichi Mishima, Yasuhiko Takegami, Shiro Imagama, Hiroshi Kitoh

Bone reports Vol. 13 page： 100708 - 100708 2020.12

Language：English Publishing type：Research paper (scientific journal)

Achondroplasia (ACH) is the most common form of short-limbed skeletal dysplasia. Patients with ACH sometimes undergo lower limb lengthening to get functional and psychological achievements. The periosteal resection (PR) is a known mechanism to increase longitudinal bone growth without osteotomy, although the results are not predictable. It could be alternative for limb lengthening in a minimally invasive technique. The purpose of this study is to evaluate the effect of PR on acceleration of bone growth in a mouse model of ACH (Fgfr3 ach). We performed a circumferential resection of periosteum on the proximal tibia to both wild-type and Fgfr3 ach mice at the age of four weeks. The second PR was done one week later in each mouse, which was subsequently sacrificed at the age of six weeks for micro-computed tomography (micro-CT) scan and histological examinations. We measured tibial bone length, bone volume, and metaphyseal trabecular bone parameters, including bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) by reconstructed micro-CT images. We also quantified the entire width of the growth plate of the proximal tibial from the sections stained with hematoxylin and eosin. Tibial bone length and bone volume of the PR side were significantly larger than the sham side in wild-type mice, while they were not statistically significant in Fgfr3 ach mice. The BV/TV and Tb.N in the metaphysis were significantly decreased in the PR side of both mice. The histological analysis revealed that the growth plate of the proximal tibia was significantly wider in the PR side of wild-type mice while it showed no difference in width between the PR side and the sham side in Fgfr3 ach mice. PR promoted longitudinal bone growth in wild-type mice, but it exhibited only a marginal effect on bone growth in Fgfr3 ach mice.

DOI： 10.1016/j.bonr.2020.100708

Influence of Global Spine Sagittal Balance and Spinal Degenerative Changes on Locomotive Syndrome Risk in a Middle-Age and Elderly Community-Living Population. Reviewed International journal Open Access

Masaaki Machino, Kei Ando, Kazuyoshi Kobayashi, Hiroaki Nakashima, Shunsuke Kanbara, Sadayuki Ito, Taro Inoue, Hidetoshi Yamaguchi, Hiroyuki Koshimizu, Taisuke Seki, Shinya Ishizuka, Yasuhiko Takegami, Naoki Ishiguro, Yukiharu Hasegawa, Shiro Imagama

BioMed research international Vol. 2020 page： 3274864 - 3274864 2020.9

Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The aim of this study was to describe the characteristics of each locomotive syndrome (LS) risk stage, including global spine sagittal alignment, spinal degenerative changes evident on plain radiographs, low back pain (LBP), muscle strength, and physical ability in middle-aged and elderly people in a health checkup. METHODS: This study included 211 healthy Japanese volunteers (89 men and 122 women; mean age, 64.0 years) who underwent assessment with both radiographs and Spinal Mouse. Spinal sagittal parameters included thoracic kyphosis angle (TKA), lumbar lordosis angle (LLA), sagittal vertical axis, and spinal inclination angle (SIA). Lumbar disc height (LDH) and lumbar osteophyte formation (LOF) at each level were evaluated as the spinal degenerative changes. The LS assessment comprised three tests: stand-up test, two-step test, and 25-question Geriatric Locomotive Function Scale (GLFS-25). The subjects were divided into three groups (no risk, stage 1 LS, or stage 2 LS) according to LS risk test criteria. The prevalence of LBP was investigated with a visual analogue scale (VAS), and physical performances were also compared among the groups. RESULTS: Of the participants, 122 had no risk of LS, 56 had stage 1 LS risk, and 29 had stage 2 LS risk. With increasing LS risk stage, the prevalence of and VAS score for LBP increased significantly, and back muscle strength and physical abilities decreased significantly. The TKA did not differ among the three groups. The LLA decreased gradually with LS risk stage (P = 0.0001). At each level except L1-L2 and L5-S1, LDH decreased gradually with LS risk stage. The prevalence of LOF increased significantly with increasing LS risk stage. The SIA increased significantly with LS risk stage (P = 0.0167). CONCLUSIONS: Participants with LS had higher prevalence of spinal degeneration, small LLA, and global spinal imbalance by anterior spinal inclination.

DOI： 10.1155/2020/3274864

Associations of Serum MicroRNA with Bone Mineral Density in Community-Dwelling Subjects: The Yakumo Study. Reviewed International journal Open Access

Hiroaki Nakashima, Kei Ando, Kazuyoshi Kobayashi, Taisuke Seki, Shinya Ishizuka, Ryosuke Fujii, Yasuhiko Takegami, Hiroya Yamada, Yoshitaka Ando, Koji Suzuki, Yukiharu Hasegawa, Shiro Imagama

BioMed research international Vol. 2020 page： 5047243 - 5047243 2020.7

Language：English Publishing type：Research paper (scientific journal)

Osteoporosis is a disease characterized by deterioration of bone tissue and mass, with an increasing global prevalence. Therefore, the discovery of biomarkers for osteoporosis would help to guide appropriate treatment. Circulating microRNAs (miRNAs) have become increasingly recognized as biomarkers for detecting diseases. However, few studies have investigated the association of circulating miRNA with osteoporosis in the general population. The aim of this study was to identify miRNA associated with osteoporosis in a general resident health check-up for potential use as an osteoporosis biomarker. We conducted a cross-sectional study as part of a health check-up program and recruited 352 volunteers (139 men, 213 women, mean age 64.1 ± 9.6 years). Osteoporosis was diagnosed according to the WHO classification. Twenty-two candidate microRNAs were screened through real-time quantitative PCR, and miRNAs associated with osteoporosis were analyzed using logistic regression analysis including other risk factors. In total, 95 females and 30 males were diagnosed with osteoporosis with bone mineral density tests (BMD: T-score < -2.5). We found that miR195 was significantly lower in females, while miR150 and miR222 were significantly higher in males. The results of the logistic regression analysis indicated that in females, higher age and lower miR195 (odds ratio: 0.45, 95% confidential interval: 0.03-0.98) were significant risk factors for lower BMD, while the presence of a smoking habit and lower miR150 (odds ratio: 1.35, 95% confidential interval: 1.02-1.79) were significant risk factors for osteoporosis. Serum levels of miR195 and miR150 are independently associated with low bone mineral density in females and males, respectively.

DOI： 10.1155/2020/5047243

The relationship between radiographic findings and patient-reported outcomes in adult hip dysplasia patients: A hospital cross-sectional study. Reviewed

Yasuhiko Takegami, Taisuke Seki, Yusuke Osawa, Taiki Kusano, Naoki Ishiguro

Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 25 ( 4 ) page： 606 - 611 2020.7

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier {BV}

INTRODUCTION: This study aimed to clarify the relationship of individual radiographic parameters and features with the patient-reported outcome measurements (PROMs) of patients with developmental dysplasia of the hip (DDH) in a hospital-referred cross-sectional analysis. METHODS: This cross-sectional study included 108 Japanese DDH patients (female, n = 88; male, n = 20; mean age, 43.4 years). We recorded the CE angle, angle of Sharp, ARO, ADR, AHI, crossover sign, pistol grip deformity, and femoral head-neck ratio, which were measured on the AP view, and the α-angle, which was measured on the Lauenstein view. We also recorded cyst formation and osteophytes on either view. We used the Japanese Orthopaedic Association hip disease evaluation questionnaire (JHEQ) to assess the PROMs. The PROMs of patients with and without cysts or osteophytes and those of patients with or without cam or pincer deformity were compared. The relationships between specific PROMs and radiographic features were evaluated with a linear regression analysis and independent associations between PROMs and radiographic features were assessed with a multiple regression analysis using various independent variables. RESULTS: The JHEQ movement and mental values in patients with cyst formation were significantly lower in comparison to those in patients without cyst formation. The JHEQ subscale values did not differ according to the presence or absence of osteophytes, cam deformity or pincer deformity. The CE angle was found to be associated with the JHEQ movement score in the linear regression analysis. To identify radiographic features that were independently associated with each of the JHEQ subscale scores, we performed a multiple regression analysis with age, body mass index, sex and the number of affected hip joints (bilateral or unilateral) included as independent variables. The CE angle was found to be independently associated with JHEQ movement. CONCLUSION: The CE angle was independently associated with the JHEQ movement value.

DOI： 10.1016/j.jos.2019.09.007

Curved Intertrochanteric Varus Osteotomy vs Total Hip Arthroplasty for Osteonecrosis of the Femoral Head in Patients Under 50 Years Old. Reviewed International journal

Yusuke Osawa, Taisuke Seki, Toshiaki Okura, Yasuhiko Takegami, Naoki Ishiguro, Yukiharu Hasegawa

The Journal of arthroplasty Vol. 35 ( 6 ) page： 1600 - 1605 2020.6

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Given recent advances in total hip arthroplasty (THA), curved intertrochanteric varus osteotomy (CVO) is not indicated as a treatment for osteonecrosis of the femoral head (ONFH), unless indicated to maintain long-term hip function and achieve patient satisfaction. We aimed to compare the clinical outcomes of CVO with those of THA for treatment of ONFH in young adults <50 years old. METHODS: This comparative study included 105 ONFH patients: 59 patients (65 hips) who underwent CVO and 46 patients (56 hips) who underwent THA. Assessment tools included the Harris hip score (HHS), patient-reported outcomes of the Short Form-36, Oxford hip score, Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire, and University of California, Los Angeles score, together with complication and survival rates. RESULTS: Preoperative HHS was significantly higher in the CVO group than in the THA group (P < .01). At the last follow-up, no between-group differences were noted in HHS, all domains of Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire scores, Oxford hip score, and Short Form-36. University of California, Los Angeles scores and complication rates were comparable: 3% for the CVO and 7% for the THA group. The 10-year survival rate with surgery for any reason as the end point was comparable, at 91.8% for the CVO and 97.7% for the THA group. CONCLUSION: Functional outcomes, survival rate, and sporting activities for patients <50 years old undergoing CVO or THA for ONFH were comparable after a mean follow-up period of 10 years. Strict indications for CVO can help maintain hip function and patient satisfaction equivalent to that for THA, in the long term.

DOI： 10.1016/j.arth.2020.01.026

Surgery trends for osteonecrosis of the femoral head: a fifteen-year multi-centre study in Japan. Reviewed International journal Open Access

Shinya Kaneko, Yasuhiko Takegami, Taisuke Seki, Wakaba Fukushima, Takashi Sakai, Wataru Ando, Naoki Ishiguro, Nobuhiko Sugano

International orthopaedics Vol. 44 ( 4 ) page： 761 - 769 2020.4

Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal)

PURPOSE: The most appropriate procedure and at what type and stage of osteonecrosis of the femoral head (ONFH) these procedures had been argued. We attempted to clarify the trend in surgical operations with respect to the age of patients, type classification, and stage of ONFH over a period of 15 years by using the multi-center sentinel monitoring system in Japan. METHODS: We evaluated the hips of 3844 patients using this system in three phases of every five years from 2003 to 2017. We classified the surgical procedures as osteotomy (OT), hemiarthroplasty (Hemi), and total hip arthroplasty (THA). We assessed the trend in age, type classification, and stage of ONFH over three time periods; "early," and the "late." We calculated the proportion of surgeries for ONFH in each period. We used the Cochran-Armitage test to evaluate trends in proportion of two levels of characteristics across three time periods. RESULTS: The proportion of younger patients significantly decreased. The proportion of OT and Hemi decreased over time, while the proportion of THA increased. The proportion of patients with types C1 and C2 who underwent OT and Hemi decreased over time. In contrast, that of THA increased. The proportion of patients who underwent OT and Hemi significantly decreased; the proportion of patients who underwent THA significantly increased over time at all stages. CONCLUSIONS: In Japan, the younger patients underwent surgery for ONFH decreased. The patients who underwent OT and Hemi for ONFH decreased, while that of THA increased over time.

DOI： 10.1007/s00264-020-04480-6

Measurement of equivalence between the web and paper versions of the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire. Reviewed International journal

Yasuhiko Takegami, Taisuke Seki, Yoshitoshi Higuchi, Yusuke Osawa, Naoki Ishiguro

Modern rheumatology Vol. 30 ( 2 ) page： 397 - 401 2020.3

Authorship：Lead author,　Corresponding author Language：English Publishing type：Research paper (scientific journal)

Objectives: Digitised patient-reported outcome may be beneficial for physicians and patients. The Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) can only be completed with paper and pencil (pJHEQ). We newly developed a web version of the JHEQ (wJHEQ). This study aimed to determine whether the scores obtained with the wJHEQ are equivalent to those from the pJHEQ, how much the wJHEQ would decrease missing answers, and which JHEQ the participants preferred to use.Methods: To measure equivalence between the pJHEQ and wJHEQ, we evaluated the mean score difference for each subscale (pain, movement, mental) and Visual Analogue Scale (VAS; satisfaction, right hip pain, left hip pain) and then assessed the intraclass correlation coefficients (ICC) between the two scores. ICC values ≥0.75 were defined as excellent agreement. We used Bland-Altman analysis to assess level of agreement between the values of the two questionnaires. We compared the number of incomplete forms and amount of missing data between the two questionnaires. We investigated ease of use by asking the participants which format was easier to use.Results: This study comprised 113 patients (mean age 58.1 years, 81% female) with hip disease. Mean score differences for each subscale between the wJHEQ and pJHEQ were not significantly different. The values of ICC for each subscale and each VAS were all >0.75. All 113 participants completed the wJHEQ questionnaire, whereas nine patients did not complete the pJHEQ form. There was a significant statistical difference between the completion rate of the wJHEQ and that of the pJHEQ (p = .0017). Fifty-seven participants (55%) preferred the wJHEQ, whereas 33 participants (32%) preferred the pJHEQ.Conclusion: The wJHEQ was found to be equivalent to the original pJHEQ. The wJHEQ significantly decreased the numbers of missing answers and incomplete forms. The participants felt ease of use was nearly equivalent. The wJHEQ might help facilitate more complete assessments in clinical trials and research.

DOI： 10.1080/14397595.2019.1592799

ロコモティブシンドロームにおけるエピジェネティックな異常の解析 Yakumo study Reviewed

竹上靖彦, 関泰輔, 大澤郁介, 草野大樹, 牧田和也, 鈴木康司, 今釜史郎, 石黒直樹, 長谷川幸治

日本整形外科学会雑誌 Vol. 94 ( 2 ) page： S137 - S137 2020.3

Author Correction: Mianserin suppresses R-spondin 2-induced activation of Wnt/β-catenin signaling in chondrocytes and prevents cartilage degradation in a rat model of osteoarthritis. Reviewed International journal Open Access

Toshiaki Okura, Bisei Ohkawara, Yasuhiko Takegami, Mikako Ito, Akio Masuda, Taisuke Seki, Naoki Ishiguro, Kinji Ohno

Scientific reports Vol. 10 ( 1 ) page： 2995 - 2995 2020.2

MicroRNA-130aは骨粗鬆症の新たなバイオマーカーとなるか? 4から6年の縦断研究(Yakumo Study) Reviewed

樋口善俊, 関泰輔, 竹上靖彦, 濱田恭, 今釜史郎, 鈴木康司, 長谷川幸治, 石黒直樹

日本骨粗鬆症学会雑誌 Vol. 5 ( Suppl.1 ) page： 384 - 384 2019.9

Comparison of Wear Rate between Ceramic-on-Ceramic, Metal on Highly Cross-linked Polyethylene, and Metal-on-Metal Bearings. Reviewed International journal Open Access

Yoshitoshi Higuchi, Taisuke Seki, Daigo Morita, Daigo Komatsu, Yasuhiko Takegami, Naoki Ishiguro

Revista brasileira de ortopedia Vol. 54 ( 3 ) page： 295 - 302 2019.5

Language：English Publishing type：Research paper (scientific journal)

Objective Currently, there is a lack of evidence on the medium-term follow-up of cementless total hip arthroplasty (THA) using metal on highly cross-linked polyethylene (MoP), ceramic-on-ceramic (CoC), and metal-on-metal (MoM) bearings. Our aim was to calculate the 5- to 10-year wear rate and the incidence rate of osteolysis for 3 types of bearings. Methods A total of 77 patients underwent MoP, 105 underwent ceramic CoC, and 55 underwent MoM THAs. The average patient age at the time of surgery was 64.7, 55.9, and 59.9 years old in the MoP, CoC, and MoM bearings, respectively. Clinical and radiologic measurements at a mean follow-up of 7.6 years were analyzed. Results The mean postoperative Harris hip scores showed no difference among the groups. The mean annual liner wear rates were 0.0160, 0.0040 and 0.0054 mm/year in MoP, CoC bearings, and MoM bearings, with that of CoC bearings being significantly lower than the others. Osteolysis (14.5%) among MoM bearings was significantly more frequently observed compared with the others. Kaplan-Meier survival at 10 years with implant loosening, or revision THA as the endpoint, was 96.1% (95% confidence interval [CI]: 88.4-98.7) for MoP, 98.6% (95% CI: 90.3-98.6) for CoC bearing, and 98.2% (95% CI: 88.0-99.7) for MoM bearings ( p = 0.360). Conclusion Excellent clinical and radiological outcomes were obtained for MoP and CoC bearings.

DOI： 10.1055/s-0039-1691762

What factors predict ceramic liner malseating after ceramic-on-ceramic total hip arthroplasty? Reviewed International journal Open Access

Yoshitoshi Higuchi, Taisuke Seki, Yasuhiko Takegami, Yusuke Osawa, Taiki Kusano, Naoki Ishiguro

Orthopaedics & traumatology, surgery & research : OTSR Vol. 105 ( 3 ) page： 453 - 459 2019.5

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: There is a lack of evidence about the risk factors associated with the malseating of the acetabular liner after ceramic-on-ceramic (CoC) total hip arthroplasty (THA). Therefore, we performed a complementary retrospective case-control study to determine the factors predicting the malseating of the acetabular liner after CoC THA and to evaluate the relationship between malseating and (1) osteoarthritis, (2) particularly in terms of the new radiographic parameter "bone sclerotic length" of the acetabular bone. HYPOTHESIS: Osteoarthritis, particularly bone sclerotic length, was an independent risk factor for malseating of ceramic liners. PATIENTS AND METHODS: In total, 219 CoC THAs (174 women and 45 men) were evaluated to determine the risk factors influencing the malseating of the acetabular ceramic liner. An average patient age at the time of surgery was 55.9±9.5 years (range, 23 to 75 years). Data on patient background and preoperative radiographs, such as Tönnis grades; Crowe classification; and indices of acetabular osteoarthritis change; including bone cyst, osteophyte and bone sclerosis, were assessed. The bone sclerotic length in patients with osteoarthritis was measured as the slant distance between the bilateral edges of the sclerosis lesion of the acetabulum on the anteroposterior view. RESULTS: Preoperative less hip flexion (hazard ratio [HR]: 0.98; 95% CI: 0.97-0.99), osteoarthritis (HR: 3.15; 95% CI: 1.02-9.70) and the bone sclerotic length (HR: 1.83; 95% CI: 1.35-2.48) were independent risk factors determining the malseating of ceramic liners. Receiver operating characteristic curve analysis showed that a bone sclerotic length of 24.6mm was defined as the cut-off point for the malseating of the ceramic liner. DISCUSSION: Age, preoperative less flextion, osteoarthritis, and the bone sclerotic were independent risk factors determining malseating of ceramic liners. The acetabular shell can also deform upon insertion of the cup with sclerotic bone of the acetabulum and prevent correct seating of liners. Therefore, these factors must be taken into consideration when seating the ceramic liner. LEVEL OF EVIDENCE: Case control study III, case control retrospective design.

DOI： 10.1016/j.otsr.2019.01.009

Failed periacetabular osteotomy leads to acetabular defects during subsequent total hip arthroplasty. Reviewed International journal

Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Taiki Kusano, Naoki Ishiguro, Yukiharu Hasegawa

Archives of orthopaedic and trauma surgery Vol. 139 ( 5 ) page： 729 - 734 2019.5

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Acetabular wall defects after periacetabular osteotomy (PAO) lead to technical difficulties when performing subsequent total hip arthroplasty (THA). There is no unified consensus regarding the solution for THA socket installation after PAO. In the current study, we performed computed tomography (CT)-based simulation of socket installation and evaluated the acetabular defect following THA after PAO and after primary osteoarthritis (OA). PATIENTS AND METHODS: The study group comprised 55 patients (56 hips) who underwent THA after PAO. For the control group, after matching for age, sex, and Crowe classification, we included 55 patients (56 hips) who underwent primary THA for hip dysplasia. We evaluated the anterior, posterior, and superior acetabular sector angle (ASA) and medial wall thickness (MWT) at the anatomical hip center (at the 20-mm vertical hip level from teardrop) in the study group (anatomical PAO group) and control group (primary OA group). In addition, we investigated the changes in the socket covering when the socket was positioned 10 mm above the anatomical hip center (30 mm above the teardrop; elevated osteotomy group). RESULTS: All ASA and MWT values were significantly smaller in the anatomical PAO group than in the primary OA group. In particular, the individuals with a Crowe classification of II/III in the anatomical PAO group presented severe acetabular defects. However, the elevated PAO group had a significantly larger ASA compared to the anatomical PAO group, with improved socket coverings. CONCLUSION: Acetabular defects in the anatomical hip center following THA after PAO were significantly common compared to those after primary THA. Elevation of hip joint centers as much as 10 mm is one therapeutic option in the case of severe acetabular defects following THA after PAO.

DOI： 10.1007/s00402-019-03174-y

THE ASSOCIATIONS BETWEEN CIRCULATING MICRORNAS AND OSTEOARTHRITIS OF THE KNEE IN COMMUNITY-DWELLING PEOPLE: YAKUMO STUDY Reviewed

Takegami, Y; Seki, T; Imagama, S; Ishiguro, N

OSTEOARTHRITIS AND CARTILAGE Vol. 27 page： S282 - S283 2019.4

Mianserin suppresses R-spondin 2-induced activation of Wnt/β-catenin signaling in chondrocytes and prevents cartilage degradation in a rat model of osteoarthritis. Reviewed International journal Open Access

Okura T, Ohkawara B, Takegami Y, Ito M, Masuda A, Seki T, Ishiguro N, Ohno K

Scientific reports Vol. 9 ( 1 ) page： 2808 - 2808 2019.2

Language：English Publishing type：Research paper (scientific journal)

Aberrant activation of the Wnt/β-catenin signaling pathway promotes the progression of osteoarthritis (OA). We previously reported that R-spondin 2 (Rspo2), an activator of the Wnt/β-catenin signaling, facilitates differentiation of proliferating chondrocytes into hypertrophic chondrocytes by enhancing Wnt/β-catenin signaling in endochondral ossification. However, the role of Rspo2 in OA remains elusive. Here, we showed that the amounts of Rspo2 protein in synovial fluid were increased in OA patients. We searched for a preapproved drug that suppresses Rspo2-induced Wnt/β-catenin signaling in chondrogenic cells and reduces joint pathology in a rat model of OA. In Rspo2-treated ATDC5 cells, mianserin, a tetracyclic antidepressant, inhibited Wnt/β-catenin signaling, increased proteoglycan production, and upregulated chondrogenic marker genes. Mianserin suppressed Rspo2-induced accumulation of β-catenin and phosphorylation of Lrp6. We identified that mianserin blocked binding of Rspo2 to its receptor Lgr5. We also observed that intraarticular administration of mianserin suppressed β-catenin accumulation and prevented OA progression in a rat model of OA. We conclude that mianserin suppresses abnormally activated Wnt/β-catenin signaling in OA by inhibiting binding of Rspo2 to Lgr5.

DOI： 10.1038/s41598-019-39393-x

Acetabular fracture non-union with pelvic discontinuity treated with two-stage total hip arthroplasty after intra- and extra-articular plate fixation. Reviewed

Daigo Morita, Taisuke Seki, Yasuhiko Takegami, Takehiro Kasai, Yoshitoshi Higuchi, Naoki Ishiguro

Nagoya journal of medical science Vol. 81 ( 1 ) page： 113 - 119 2019.2

Language：English Publishing type：Research paper (scientific journal)

Surgical intervention for the treatment of acetabular fracture non-union is often challenging. Here, we present a case of acetabular fracture non-union with pelvic discontinuity in a patient who underwent cemented total hip arthroplasty (THA) after intra- and extra-articular plate fixation. The case was a 70-year-old male with left T-shaped acetabular fracture non-union neglected for 5 months after the injury. The anterior and posterior columns were not healed, and the articular surface was displaced toward the medial side with a protrusion of the collapsed femoral head. As the first surgical intervention, we performed intra- and extra-articular plate fixation after femoral head decapitation. We fixed non-union regions from the inferior acetabular margin to the anterior column using a pelvic reconstruction plate bent three-dimensionally at the acetabular curvature on the intra-articular side. Furthermore, we fixed that of the posterior column on the outside of the acetabulum using a bent pelvic reconstruction plate. Union of the anterior and posterior columns was observed at 4 and 6 months after the first surgical intervention. At 7 months, we performed a cemented THA without additional bone grafting. At 1-year follow-up, the patient did not have left coxalgia and could walk without any gait supports. Based on our experience, we propose this surgical protocol as a useful treatment option for cases of acetabular fracture non-union.

DOI： 10.18999/nagjms.81.1.113

32-mm ceramic-on-ceramic total hip arthroplasty versus 28-mm ceramic bearings: 5- to 15-year follow-up study. Reviewed International journal Open Access

Higuchi Y, Seki T, Hasegawa Y, Takegami Y, Morita D, Ishiguro N

Hip international : the journal of clinical and experimental research on hip pathology and therapy Vol. 29 ( 1 ) page： 65 - 71 2019.1

Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION:: This study aimed to compare the clinical and radiographic results of 28-mm ceramic-on-ceramic (CoC) total hip arthroplasty (THA) to those of 32-mm CoC during a 5- to 15-year follow-up period. METHODS:: 107 joints (95 women and 6 men) underwent 28-mm CoC, and 60 (49 women and 7 men) underwent 32-mm CoC. The average patient age at the time of surgery was 56.1 and 55.7 years in the 28-mm and 32-mm CoC groups, respectively. Clinical and radiologic measurements of all patients were analysed. RESULTS:: The mean preoperative Harris hip score (HHS) was similar in the 2 groups (28-mm, 58.9; and 32-mm, 58.5). However, at final follow-up, the mean HHS of the 32-mm CoC (91.8) was significantly better than that of the 28-mm CoC (88.2) ( p = 0.003), as were the ranges of motion (ROM) for flexion (98.3 ± 13.5° vs. 87.3 ± 19.3°, p < 0.001) and abduction (27.8 ± 14.9° vs. 22.1 ± 19.3°, p = 0.007). The mean wear rate was 0.0044 mm/year for the 28-mm CoC and 0.0044 mm/year for the 32-mm CoC. No ceramic fractures were found in the 2 groups. One joint in the 28-mm CoC (0.9%) required revision owing to progressive osteolysis. Kaplan-Meier survival at 10 years, with implant loosening or revision THA as the endpoint, was 98.3% for 28-mm CoC and 100% for 32-mm CoC ( p = 0.465). CONCLUSION:: There was no significant difference in ceramic-related complications between the 2 groups. Our study demonstrated that the 32-mm and 28-mm CoC are safe and are associated with good clinical outcomes.

DOI： 10.1177/1120700018760971

Same survival but higher rate of osteolysis for metal-on-metal Ultamet versus ceramic-on-ceramic in patients undergoing primary total hip arthroplasty after 8 years of follow-up. Reviewed International journal Open Access

Higuchi Y, Seki T, Takegami Y, Komatsu D, Morita D, Ishiguro N

Orthopaedics & traumatology, surgery & research : OTSR Vol. 104 ( 8 ) page： 1155 - 1161 2018.12

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: To avoid wear-induced osteolysis, ceramic-on-ceramic (CoC) and metal-on-metal (MoM) bearings have been developed. At present, there are no direct material related clinical comparisons between cementless total hip arthroplasty with CoC and MoM at more than 5-year follow-up. The bearing that is more likely to prevent osteolysis is still controversial. Therefore, we performed a retrospective case control study evaluating CoC and MoM cementless THAs in order to: - compare the longevity and complications for CoC and MoM THAs at 5-10 years postoperatively; - compare the incidence of osteolysis between both type THAs; - evaluate pseudotumors in MoM THAs. HYPOTHESIS: CoC THAs will have a lower rate of osteolysis, better longevity, and better clinical outcomes than MoM THAs. PATIENTS AND METHODS: Ninety-six hips underwent CoC THAs, and 56 hips underwent MoM THA (Ultamet, Pinnacle, Depuy). Average patient age at the time of surgery was 57.1 years (range, 28 to 77 years). RESULTS: There were no differences with regard to the Harris hip score (89.5 and 90.3 for the CoC and MoM groups, respectively). Osteolysis (9 hips, 14.3%) among MoM THAs were significantly more frequently observed compared to CoC THAs (2 hips, 2.1%). Kaplan-Meier survival at 8 years with implant loosening or revision THA as the endpoint was 98.2% (95% CI: 87.8-99.8) for CoC, and 98.6% (95% CI: 90.2-99.8) for MoM (p=0.684). There was one audible squeaking (1.0%) and no ceramic fracture among CoC THAs. Five (8.9%) hips showed pseudotumors among MoM THAs. DISCUSSION: CoC THAs had a low incidence of osteolysis. No significant difference was seen in the 8-year survival rate between implants, when using implant loosening and revision THA as endpoints. These data indicate that CoC THAs have excellent clinical and radiological outcomes, compared with MoM THAs. Ultamet MoM had a higher rate of osteolysis compared to other MoM bearings; the cup modularity (without polyethylene) and the use of 36mm heads as well as the process of production (after 2006) may play a significant role in the higher rate of osteolysis. LEVEL OF EVIDENCE: III, Case control study, case control retrospective design.

DOI： 10.1016/j.otsr.2018.08.005

A Possible New Radiographic Predictor of Progression of Osteoarthritis in Developmental Dysplasia of the Hip: The Center Gap. Reviewed International journal Open Access

Morita D, Hasegawa Y, Seki T, Amano T, Takegami Y, Kasai T, Higuchi Y, Ishiguro N

Clinical orthopaedics and related research Vol. 476 ( 11 ) page： 2157 - 2166 2018.11

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Patients with comparable severities of developmental dysplasia of the hip (DDH) may variably progress to osteoarthritis (OA) over time. Although joint congruency may be associated with OA progression in patients with DDH, it has only been assessed subjectively. We assessed the gap between the rotational centers of the acetabulum and femoral head (center gap) as a possible predictive measure of OA progression in patients with DDH. QUESTIONS/PURPOSES: In patients with bilateral DDH, we asked: (1) What is the probability of OA progression (Tönnis grade) or symptom development (pain) in the asymptomatic contralateral hip of patients with DDH undergoing unilateral joint-preserving surgery? (2) Is the center gap measurement associated with OA progression or symptom development in these hips? (3) Is the center gap measurement correlated with previous radiographic parameters? METHODS: A total of 297 patients (319 hips) underwent unilateral eccentric rotational acetabular osteotomy at our institution between July 1989 and December 1999. We performed no other joint-preserving surgery to treat patients with DDH during this timeframe. The inclusion criteria for the study were patients younger than 55 years of age, the contralateral hip classified as Tönnis Grade 0, no previous surgical interventions, and asymptomatic at the time of eccentric rotational acetabular osteotomy (155 patients, 155 hips). The exclusion criteria were a contralateral hip without dysplasia (four patients, four hips), loss to followup before 10 years (42 patients, 42 hips [27%]), or missing medical records or radiographs (21 patients, 21 hips [14%]). The remaining 88 patients (88 hips; 11 males and 77 females) with a mean age of 39 years (range, 17-53 years) and mean followup of 20 years (range, 10-27 years) were analyzed. From the institutional database, radiographic parameters including the center gap in the AP view were assessed using radiographs at the time of eccentric rotational acetabular osteotomy, and the Tönnis grade was recorded 1 year postoperatively and annually thereafter retrospectively. We defined migration of the rotational center of the femoral head based on the rotational center of the acetabulum in the horizontal plane as center gap X (mm) and in the vertical plane as center gap Y (mm) and defined the absolute value between the centers as center gap distance (mm). Using κ statistics, intra- and interobserver reliabilities were determined to be 0.896 and 0.857 for center gap X, 0.912 and 0.874 for center gap Y, and 0.912 and 0.901 for the center gap distance, respectively. When patients reported any contralateral ipsilateral hip pain during clinic visits, the hip was considered symptomatic. Kaplan-Meier survivorship analyses were performed with OA progression or symptom development in the nonoperative hip as the endpoint. Multivariate analyses were performed to assess risk factors for each outcome using the Cox proportional hazards model. Correlation analyses between the center gap and other parameters including lateral center-edge angle, femoral head extrusion index, acetabular depth-to-width index, femoral head lateralization, minimum width of the joint space, head sphericity, and joint congruency were performed using Pearson's correlation coefficient. RESULTS: At 20 years postoperatively, the probability of OA progression in the nonoperative hip was 13% (95% confidence interval [CI], 7.1-22.1) and the probability of symptom development was 34% (95% CI, 24.7-46.1). The center gap X measurements in the groups with OA progression (lateral 2.0 ± 2.1 [SD] mm) or symptom development (lateral 0.9 ± 2.4 mm) took a more lateral direction than those in the group without OA progression (medial 0.4 ± 2.1 mm) or symptom development (medial 0.5 ± 2.0 mm) (OA progression, p < 0.001; symptom development, p = 0.005). The center gap Y measurements in the groups with OA progression (distal 2.7 ± 7.1 mm) or symptom development (distal 2.1 ± 6.0 mm) took a more distal direction than those in the group without OA progression (proximal 1.6 ± 6.2 mm) or symptom development (proximal 2.5 ± 6.1 mm) (OA progression, p = 0.027; symptom development, p = 0.001). Independent risk factors for OA progression were the femoral head extrusion index (hazard ratio [HR], 1.11; 95% CI, 1.01-1.22; p = 0.028) and the center gap X (HR, 1.52; 95% CI, 1.07-2.16; p = 0.019), whereas no independent risk factors for symptom development were found. The center gap in the horizontal plane had no correlations with any other radiographic parameter studied. CONCLUSIONS: The center gap in the horizontal plane had a modest association with OA progression in this group of patients with DDH. Future studies are needed to determine the normal value of the center gap for patients without DDH and to assess the center gap in lateral radiographic views. LEVEL OF EVIDENCE: Level IV, prognostic study.

DOI： 10.1097/CORR.0000000000000458

Comparison of cementless total hip arthroplasty survivorship between metal-on-highly cross-linked polyethylene and ceramic-on-ceramic bearings: A case control study with a 5–9-year follow-up Reviewed

Vol. 104 ( 5 ) 2018.9

Drug repositioning strategyを用いた異所性骨化を抑制する薬剤探索 Reviewed

草野大樹, 中谷直史, 笠井健広, 竹上靖彦, 関泰輔, 大野欽司, 上住聡芳, 山田治基, 土田邦博, 石黒直樹

日本整形外科学会雑誌 Vol. 92 ( 8 ) page： S1807 - S1807 2018.8

The influence of early radiolucent lines appearing on femoral head penetration into HXLPE cemented sockets. Reviewed International journal

Morita D, Seki T, Higuchi Y, Takegami Y, Amano T, Ishiguro N

Hip international : the journal of clinical and experimental research on hip pathology and therapy Vol. 28 ( 4 ) page： 369 - 374 2018.7

Language：English Publishing type：Research paper (scientific journal)

INTRODUCTION: This study investigates differences in femoral head penetration between highly cross-linked polyethylene (HXLPE) cemented sockets both with and without radiolucent lines (RLLs) in the early postoperative phase and at 5 years follow-up. METHODS: There were 35 patients (37 hips), mean age of 66.8 years, who underwent total hip arthroplasty (THA) using highly HXLPE cemented sockets. They were divided into 2 groups based on postoperative the early appearance of RLLs. Femoral head penetrations on both anteroposterior- and Lauenstein-view radiographs were evaluated, and the mean polyethylene (PE) wear rate was calculated based on femoral head penetrations between 2 and 5 years. RESULTS: Femoral head penetrations in the proximal direction were 0.075 mm and 0.150 mm in the RLL and non-RLL groups at 1 year postoperatively ( p = 0.019). At 5 years measured penetration was 0.107 mm and 0.125 mm in the RLL and non-RLL groups, respectively ( p = 0.320). The mean PE wear rates in anteroposterior-view were 0.008 mm/year and 0.003 mm/year in the RLL and non-RLL groups ( p = 0.390) and those in Lauenstein-view were 0.010 mm/year and 0.005 mm/year, respectively ( p = 0.239). CONCLUSIONS: In the RLL group, the PE bedding-in was less compared with those in the non-RLL group. Additionally, the mean PE wear rate in the RLL group tended to be higher than that in the non-RLL group. The distribution of stress loading through the cement may differ according to whether early RLLs appear.

DOI： 10.1177/1120700018754308

Do femoral head collapse and the contralateral condition affect patient-reported quality of life and referral pain in patients with osteonecrosis of the femoral head? Reviewed International journal Open Access

Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Takehiro Kasai, Yoshitoshi Higuchi, Naoki Ishiguro

International Orthopaedics Vol. 42 ( 7 ) page： 1463 - 1468 2018.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Verlag

Purposes: The objectives of this study were to investigate patient-reported outcomes and referral pain at the first visit in patients with osteonecrosis of the femoral head (ONFH) and to clarify the influence of collapse of the femoral head and the contralateral condition. Methods: The study included 105 patients (130 hips) with ONFH at the first visit, who were divided into two groups based on the presence of bilateral walking hip pain (bilateral group 25 patients, 50 hips) and unilateral hip pain (unilateral group 80 patients, 80 hips). We compared the Short Form-36 (SF-36), Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ), and visual analog scale (VAS) responses for hip, knee, and low back pain between the groups to investigate the influence of the contralateral condition. Regarding the influence of femoral head collapse, we investigated these subjects based on the stage classification in the unilateral group. Results: The physical component summary (PCS) of the SF-36 and all domains of the JHEQ were poorer in the bilateral group than in the unilateral group. In addition, the VAS score for low back pain was significantly poorer in the bilateral group than in the unilateral group. Regarding the collapse of the femoral head, the SF-36 for the PCS and JHEQ for pain had a significant relationship in the ONFH stage. The VAS scores for hip and knee pain had a significant relationship in the ONFH stage. Conclusion: Collapse of the femoral head and the contralateral condition of ONFH strongly affect patients’ activities of daily life.

DOI： 10.1007/s00264-018-3867-1

Cementless total hip arthroplasty for osteonecrosis and osteoarthritis produce similar results at ten years follow-up when matched for age and gender Reviewed International journal

Yusuke Osawa, Taisuke Seki, Yasuhiko Takegami, Taiki Kusano, Kazuya Makida, Naoki Ishiguro

International Orthopaedics Vol. 42 ( 7 ) page： 1683 - 1688 2018.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Verlag

Purpose: The aim of this study was to compare the clinical outcomes of cementless total hip arthroplasty (THA) used for the treatment of osteonecrosis of the femoral head (ONFH) and for osteoarthritis (OA) at a mean ten years follow-up. Methods: Case-control study of 78 patients (86 hips) who underwent THA for ONFH treatment (ONFH group). Patients were matched for age and sex to 78 patients (86 hips) who underwent THA for OA (OA group). We compared the clinical and patient-reported outcomes, implant survival rates, and rates of complications between the groups. Results: There were no between-group differences in the Harris Hip Score and in the following patient-reported outcomes at the last follow-up: Japanese Orthopedic Association Hip-Disease Evaluation Questionnaire (JHEQ) pain and movement scores and the Physical Component Summary and Role/Social Component Summary scores of Short Form-36 (SF-36). However, the mental score of the JHEQ, the Mental Component Summary score of SF-36, and The Visual Analog Scale score for satisfaction were lower for the ONFH group than for OA group. The rate of complication was equivalent between the groups: 5% for the ONFH group and 3% for the OA group. The ten year implant survival rate was equivalent between the groups, at 97.5% for the ONFH group and 98.2% for the OA group. Conclusion: The functional outcomes, implant survival, and rate of complications for cementless THAs are comparable at a mean follow-up of ten years for ONFH and OA.

DOI： 10.1007/s00264-018-3987-7

Preoperative Canal Bone Ratio is Related to High-Degree Stress Shielding: A Minimum 5-Year Follow-Up Study of a Proximally Hydroxyapatite-Coated Straight Tapered Titanium Femoral Component Reviewed International journal

Taiki Kusano, Taisuke Seki, Yoshitoshi Higuchi, Yasuhiko Takegami, Yusuke Osawa, Naoki Ishiguro

Journal of Arthroplasty Vol. 33 ( 6 ) page： 1764 - 1769 2018.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Churchill Livingstone Inc.

Background: Few studies have reported risk factors for stress shielding. We sought to evaluate clinical and radiographic outcomes of a proximally hydroxyapatite-coated straight tapered titanium femoral component stem during a minimum 5-year follow-up and identify factors associated with high-degree stress shielding. Methods: A total of 156 total hip arthroplasties (n = 124
98 women and 26 men
mean age, 56.5 years) with a minimum follow-up period of 5 years were included in the study. Clinical and radiologic measurements at follow-up (range, 5-16.3 years
mean, 10.2 years) were analyzed. Results: The mean preoperative Harris Hip Score (HHS) was 56.6, and the mean HHS at the latest follow-up was considerably improved at 86.8. Stress shielding at the latest follow-up was low degree in 136 (87%) hips and high degree in 20 (13%) hips. On average, high-degree stress shielding occurred 9.9 years (5-14 years) after surgery. The results of Cox proportional hazard analysis showed that a canal bone ratio ≥ 0.49 was an independent risk factor for high-degree stress shielding (P =.0075
hazard ratio, 3.981). HHS at the latest follow-up was significantly lower in high-degree stress shielding than in low-degree stress shielding (80.7 and 87.7, respectively
P =.0030). Conclusion: Preoperative canal bone ratio ≥ 0.49 is independently associated with high-degree stress shielding. In addition, the number of cases with high-degree stress shielding significantly increased over time during a mean 10-year follow-up.

DOI： 10.1016/j.arth.2017.12.019

Patient-reported outcomes in patients who undergo total hip arthroplasty after periacetabular osteotomy Reviewed

Yusuke Osawa, Yukiharu Hasegawa, Taisuke Seki, Yasuhiko Takegami, Takafumi Amano, Naoki Ishiguro

Journal of Orthopaedic Science Vol. 23 ( 2 ) page： 346 - 349 2018.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier

Background: There has been constant discussion about whether the clinical outcome of THA after periacetabular osteotomy (PAO) is equivalent to that after primary total hip arthroplasty (THA). However, there have been few reports about patient-reported outcomes (PRO) for those who undergo THA after PAO. We compared the pre- and postoperative PRO of patients who underwent THA after PAO and those who underwent primary THA alone. Methods: We performed a case–control study. Twenty-seven patients (29 hips) underwent THA after PAO (osteotomy group)
their mean age at surgery was 57.2 years, and they underwent postoperative follow-up for a mean period of 3.0 years. For the control group, after matching age, sex, and Crowe classification, we included 54 patients (58 joints) who underwent primary THA for hip dysplasia. Assessment performed preoperatively and at the last follow-up included the Harris hip score, the Short Form 36 (SF-36) for the Physical Component Summary (PCS), Mental Component Summary (MCS), and Role/Social Component Summary (RCS) domains, Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ) for pain, movement, and mental health, and the visual analog scale (VAS) score of hip pain and satisfaction. Results: The two groups demonstrated no significant difference in the preoperative Harris hip score, each domain of the SF-36, JHEQ, and the VAS score of hip pain and satisfaction. The osteotomy group demonstrated significantly poor Harris hip scores for gait and activity, and JHEQ for movement at the last follow-up. There was no significant difference in each domain of the SF-36 and the VAS score of hip pain and satisfaction at the last follow-up. Conclusion: Previous PAO affects the quality of physical function in patients who undergo subsequent THA.

DOI： 10.1016/j.jos.2017.11.001

Differences in Femoral Head Penetration Between Highly Cross-Linked Polyethylene Cemented Sockets and Uncemented Liners Reviewed International journal

Daigo Morita, Taisuke Seki, Yoshitoshi Higuchi, Yasuhiko Takegami, Naoki Ishiguro

JOURNAL OF ARTHROPLASTY Vol. 32 ( 12 ) page： 3796 - 3801 2017.12

Language：English Publishing type：Research paper (scientific journal) Publisher：CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS

Background: This study aimed at investigating differences in femoral head penetration between highly cross-linked polyethylene (HXLPE) cemented sockets and uncemented liners during 5 years postoperatively.
Methods: Ninety-six patients (106 hips) with a mean age of 64.4 (range, 35-83) years underwent total hip arthroplasty using a HXLPE cemented socket or liner and were respectively divided into cemented (35 patients [37 hips]) and uncemented (61 patients [69 hips]) groups. Femoral head penetrations were evaluated on both anteroposterior (AP)-view and Lauenstein-view radiographs, and mean polyethylene (PE) wear rates were calculated based on femoral head penetration from 2 to 5 years. Multivariate analyses were performed to assess risk factors for PE wear.
Results: At 5 years postoperatively, the cemented and uncemented groups exhibited proximal direction femoral head penetrations of 0.103 mm and 0.124 mm (P = .226) and anterior direction penetrations of 0.090 mm and 0.151 mm (P = .002), respectively. The corresponding mean PE wear rates were 0.004 mm/y and 0.009 mm/y in the AP-view (P = .286) and 0.005 mm/y and 0.012 mm/y in the Lauenstein-view (P = .168), respectively. Left-side operation and high activity were independent risk factors for PE wear on AP-view.
Conclusion: When HXLPE was used, all mean PE wear rates were very low and those of cemented sockets and uncemented liners were very similar. PE particle theory suggests that the occurrence of osteolysis and related aseptic loosening might consequently decrease. (C) 2017 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.arth.2017.07.017

Independent association of joint space narrowing, cyst formation and health-related quality of life of patients with hip osteoarthritis in Japan Reviewed

Yasuhiko Takegami, Taisuke Seki, Yoshitoshi Higuchi, Daigo Komatsu, Yoshihiro Nishida, Naoki Ishiguro

JOURNAL OF ORTHOPAEDIC SCIENCE Vol. 22 ( 6 ) page： 1096 - 1101 2017.11

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Introduction: This study clarified individual associations of joint space narrowing (JSN) and radiographic features (RF) of hip osteoarthritis (HOA), i.e., cyst and osteophyte formation and subchondral sclerosis, with quality of life (QOL) in Japanese HOA patients.
Methods: This cross-sectional study comprised 117 Japanese HOA patients (98 women, 17 men; mean age, 61.2 years). We recorded locations and the size of each RF and measured JSN on the acetabular side (Ace) or femoral head (FH). We evaluated pain with the Visual Analog Scale (VAS) and assessed QOL with the physical component summary (PCS) and mental component summary (MCS) of the Medical Outcomes Study Short Form-36. We compared QOL with/without the RF on the Ace, FH or both and analyzed relationships between each RF and VAS, PCS and MCS with linear regression analysis. We assessed independent associations of each RF with PCS and MCS with multiple regression analysis using various independent variables.
Results: VAS values with the cyst on the Ace only were significantly lower than those with the cyst at both locations. PCS values with the cyst on the Ace only were significantly higher than those for both locations. Independent associations existed for maximum cyst length on the Ace and FH with VAS and for JSN with PCS, but none existed for MCS.
Conclusions: Our study suggested that the location and the size of the cyst formation were associated with both VAS and QOL in Japanese HOA patients. The JSN was independently associated with the PCS. (C) 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jos.2017.08.014

Total Hip Arthroplasty After Transtrochanteric Rotational Osteotomy for Osteonecrosis of the Femoral Head: A Mean 10-Year Follow-Up Reviewed International journal

Yusuke Osawa, Taisuke Seki, Daigo Morita, Yasuhiko Takegami, Toshiaki Okura, Naoki Ishiguro

JOURNAL OF ARTHROPLASTY Vol. 32 ( 10 ) page： 3088 - 3092 2017.10

Language：English Publishing type：Research paper (scientific journal) Publisher：CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS

Background: The objective of the present study was to investigate clinical, quality of life, and radiographic outcomes of patients who underwent total hip arthroplasty (THA) after transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH).
Methods: We performed a case-control study. The participants were 29 patients (34 hips) who underwent THA after TRO (TRO group). These patients had a mean age at surgery of 51.6 years (range, 30-72 years) and underwent postoperative follow-up for a mean period of 10.5 years (range, 3-19 years). For the control group (primary group), we included 58 patients (68 hips) who underwent primary THA for ONFH, matching for age and gender.
Results: The Harris Hip Scores at the last follow-up were significantly poorer in the TRO group than in the primary group. Similarly, preoperative and postoperative hip range of motion was significantly poorer in the TRO group than in the primary group. Quality of life (Short Form-36, Oxford Hip Score, and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire) and complication rates were not significantly different between the groups. The survival rates at 10 years, with revision for any reason as the endpoint, were 81% in the TRO group and 91% in the primary group, showing no significant difference between the groups. The TRO group had a larger average postoperative leg length discrepancy and a higher rate of stem malalignment than the primary group.
Conclusion: The clinical outcomes of THA after TRO for ONFH were poorer than those of primary THA. (C) 2017 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.arth.2017.05.020

The poor quality and reliability of information on periacetabular osteotomy on the internet in Japan Reviewed

Yasuhiko Takegami, Taisuke Seki, Takafumi Amano, Yoshitoshi Higuchi, Daigo Komatsu, Yoshihiro Nishida, Naoki Ishiguro

NAGOYA JOURNAL OF MEDICAL SCIENCE Vol. 79 ( 3 ) page： 375 - 385 2017.8

Language：English Publishing type：Research paper (scientific journal) Publisher：NAGOYA UNIV, SCH MED

Although many patients use the internet to access health-related information, the quality and the reliability of the information is highly inconsistent. Periacetabular osteotomy (PAO) is one of the surgical procedures for hip dysplasia. However, medical information on PAO is limited on the internet. This study aims to evaluate the quality and reliability of information available on PAO on the internet in Japan. A web search was conducted on two search engines for the following terms: "hip osteotomy," " pelvic osteotomy," and " osteotomy for hip preservation" in Japanese. In total, we found 120 websites. To determine the quality and reliability of information on each website, we used the Health on the Net Foundation (HON) score, the Brief DISCERN score, and an osteotomy-specific content (OSC) score. After eliminating duplicate websites, we reviewed 49 unique websites. Only three websites (6.1%) had good reliability, as indicated by their HON scores. Twelve websites (24.4%) had good-quality information, as measured by their Brief DISCERN scores. As evaluated by their OSC scores, physician websites were found to be biased toward etiology and surgical indication and did not provide information on the complications of procedures. Nonphysician websites were generally insufficient. The information about PAO on the internet is, therefore, unreliable and of poor-quality for Japanese patients.

DOI： 10.18999/nagjms.79.3.375

変形性股関節症患者の身体活動量および活動強度に影響する因子 Reviewed

鈴木謙太郎, 加古誠人, 寺井千晶, 安田尚太郎, 松山美乃里, 佐藤幸治, 門野泉, 竹上靖彦, 天野貴文, 関泰輔

理学療法学Supplement Vol. 2016 ( 0 ) page： 281 - 281 2017

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：公益社団法人日本理学療法士協会

<p>【はじめに，目的】</p><p></p><p>我々はこれまでに，人工股関節全置換術（THA）前の身体活動量は術後早期の歩行能力や在院日数に関連するという結果を得ており，術前の変形性股関節症（股OA）患者にとって身体活動量低下の予防は重要であると考えられる。3軸加速度計は，患者の実際の日常生活において，歩数などで示される身体活動量に加え，活動強度の測定を行うことが可能である。股OA患者の身体活動量や活動強度は，痛みや身体機能，精神機能など様々な因子の影響を受けることが予測されるが，これらを包括的に検討した報告はない。本研究の目的は，3軸加速度計を用いて股OA患者の身体活動量および活動強度に影響する因子を検討することである。</p><p></p><p>【方法】</p><p></p><p>対象は2015年12月～2016年9月に当院にて片側THAを施行された患者のうち，術前に身体活動量および活動強度，下肢関節可動域，下肢筋力，10m歩行の測定，痛みおよび精神機能に関するアンケート評価を行い，歩行非自立であった2例を除いた40例（男性7例，女性33例，年齢66.9±10.5歳）とした。3軸加速度計（ActiGraph GT3X-BT）を用いて入院前1週間分の1日平均歩数，1日のうちの低強度の身体活動時間（light physical activity；LPA），中～高強度の身体活動時間（moderate-to-vigorous physical activity；MVPA）を測定した。ハンドヘルドダイナモメーター（μTas F-100）を用い，術側，非術側の股関節外転および膝関節伸展トルクを算出した。Visual Analogue Scale（VAS），Pain Catastrophizing Scale（PCS），Hospital Anxiety and Depression Scale（HADS）を用い，痛みおよび精神機能を評価した。Pearsonの相関係数を用い歩数および活動強度と各評価項目にて相関関係を検討した。次に，歩数および活動強度を従属変数とし，これらと有意な相関関係を認めた各評価項目を独立変数に投入したステップワイズ重回帰分析を行った。いずれの検定も有意水準を5%とした。</p><p></p><p>【結果】</p><p></p><p>歩数は，術側および非術側股関節伸展可動域，非術側股関節外転可動域，非術側股関節外転トルク，HADS抑うつと有意に相関し，重回帰分析の結果，非術側股関節伸展可動域（p＜0.01，β=0.41），HADS抑うつ（p＜0.01，β=-0.36），非術側股関節外転可動域（p=0.02，β=0.35）が有意な関連因子として抽出された。LPAと有意に相関する因子は無かった。MVPAは，非術側股関節伸展可動域，非術側股関節外転可動域，年齢と有意に相関し，重回帰分析の結果，非術側股関節伸展可動域（p＜0.05，β=0.34），年齢（p＜0.05，β=-0.30）が有意な関連因子として抽出された。</p><p></p><p>【結論】</p><p></p><p>歩数，MVPAは，ともに非術側股関節伸展可動域と関連しており，非術側股関節伸展可動域の低下は身体活動量，活動強度を低下させる因子であった。また，股OA患者の精神的健康の低下は，身体活動量を低下させる因子であった。さらに，股OA患者では年齢とともに活動強度が低下することが示された。</p>

DOI： 10.14900/cjpt.2016.0281

Laterality of radiographic osteoarthritis of the knee Reviewed International journal

Daigo Komatsu, Kazuma Ikeuchi, Toshihisa Kojima, Yasuhiko Takegami, Takafumi Amano, Masaki Tsuboi, Naoki Ishiguro, Yukiharu Hasegawa

LATERALITY Vol. 22 ( 3 ) page： 340 - 353 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD

There are few reports of the laterality in radiological knee osteoarthritis (ROA). This study aimed to evaluate laterality in terms of the minimum joint space width (mJSW) and osteophyte areas (OFs) in a cross-sectorial general population screen and elucidate the association between laterality and risk of osteoarthritis. We enrolled 330 participants (mean age 64.6 years) and examined the presence of ROA (Kellgren-Lawrence grade >= 2) laterality in terms of the mJSW and OF on the medial tibia using auto-measuring software. Moreover, we examined the association between laterality and leg dominance. The right and left medial mJSWs were 4.02 +/- 0.98 mm and 4.05 +/- 1.01 mm, respectively, showing no laterality; the laterals were also similar. The participants who had osteophytes >= 1 mm(2) in the right, left, and bilateral knees were 15, 37, and 57 respectively, with osteophytes being significantly more common in the left knee. The OF was significantly larger in the left knee. Conversely, the medial and lateral mJSWs and OF did not differ according to leg dominance. The prevalence of ROA was higher and the OF was more pronounced in the left knee. However, the mJSW showed no laterality. Additionally, the mJSW and OF showed no differences according to leg dominance.

DOI： 10.1080/1357650X.2016.1199560

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