Language：English   Publisher：Nagoya Journal of Medical Science  

The diagnosis of pediatric spinal cord tumor is frequently delayed due to the presence of non-specific symptoms. We investigated the factors influencing the delay between the first symptom presentation and the diagnosis for pediatric spinal cord tumor. We retrospectively analyzed 31 patients of age <20 years (18 men, 13 women) who underwent surgery for spinal cord tumor at a single center during 1998–2018. We extracted the relevant data on patients’ symptoms, affected spinal location (cervical: C1-7, thoracic: T1-T12, and lumbosacral: L1-S), and tumor anatomical location (extradural, intradural extramedullary, and intramedullary tumor) that could potentially affect the duration of symptom presentation prior to the diagnosis. The most common symptom presented in the patients was pain (n = 22, 71.0 %). Motor symptoms such as paralysis was associated with early diagnosis (P = 0.039). The duration of symptoms prior to diagnosis was found to be significantly longer in patients with spinal tumor in the lumbar-sacral region than in those with the involvement of the cervical and thoracic regions (2.1 ± 1.7 months vs 13.6 ± 12.1 months; P = 0.006 and 2.9 ± 2.2 months vs 13.6 ± 12.1 months; P = 0.012, respectively). Our study results demonstrated that pain was the most common symptom in the examined patients, although it did not affect the delay in diagnosis, whereas the presentation of motor symptoms was helpful in the diagnosis of pediatric spinal cord tumor and the diagnosis could be delayed in lumbar-sacral spinal tumors

DOI： 10.18999/nagjms.84.3.516

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Language：Japanese   Publisher：Journal of Orthopaedic Science  

Background: The latest clinical guidelines are mandatory for physicians to follow when practicing evidence-based medicine in the treatment of low back pain. Those guidelines should target not only Japanese board-certified orthopaedic surgeons, but also primary physicians, and they should be prepared based entirely on evidence-based medicine. The Japanese Orthopaedic Association Low Back Pain guideline committee decided to update the guideline and launched the formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline with the latest data of evidence-based medicine. Methods: The Japanese Orthopaedic Association Low Back Pain guideline formulation committee revised the previous guideline based on a method for preparing clinical guidelines in Japan proposed by Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014. Two key phrases, “body of evidence” and “benefit and harm balance” were focused on in the revised version. Background and clinical questions were determined, followed by literature search related to each question. Appropriate articles were selected from all the searched literature. Structured abstracts were prepared, and then meta-analyses were performed. The strength of both the body of evidence and the recommendation was decided by the committee members. Results: Nine background and nine clinical qvuestions were determined. For each clinical question, outcomes from the literature were collected and meta-analysis was performed. Answers and explanations were described for each clinical question, and the strength of the recommendation was decided. For background questions, the recommendations were described based on previous literature. Conclusions: The 2019 clinical practice guideline for the management of low back pain was completed according to the latest evidence-based medicine. We strongly hope that this guideline serves as a benchmark for all physicians, as well as patients, in the management of low back pain.

DOI： 10.1016/j.jos.2021.06.024

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Language：English   Publisher：The Japanese Society for Spine Surgery and Related Research  

DOI： 10.22603/ssrr.2021-0010

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Language：English   Publisher：Journal of Clinical Medicine  

The aim of the current study was to compare outcomes between lateral access vertebral reconstruction (LAVR) using a rectangular footplate cage and the conventional procedure using a cylindrical footplate cage in patients with osteoporotic vertebral fracture (OVF). We included 46 patients who underwent anterior–posterior combined surgery for OVF: 24 patients underwent LAVR (Group L) and 22 underwent the conventional procedure (Group C). Preoperative, postoperative, and 1‐ and 2‐year follow‐up X‐ray images were used to measure local lordotic angle, correction loss, and cage subsidence (>2 mm in vertebral endplate depression). In anterior surgery, the operation time was significantly shorter (183 vs. 248 min, p < 0.001) and the blood loss was significantly less (148 vs. 406 mL, p = 0.01) in Group L than in Group C. In Group C, two patients had anterior instrumentation failure. Correction loss was significantly smaller in Group L than in Group C (1.9° vs. 4.9° at 1 year, p = 0.02; 2.5° vs. 6.5° at 2 years, p = 0.04, respectively). Cage subsidence was significantly less in Group L than in Group C (29% vs. 80%, p < 0.001). LAVR using a rectangular footplate cage is an effective treatment for OVF to minimize surgical invasiveness and postoperative correction loss.

DOI： 10.3390/jcm10235664

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Language：English   Publisher：Nagoya Journal of Medical Science  

An annual physical checkup is provided as part of the long-term Yakumo study. The checkup is voluntary and there is variation in the frequency of participation. The aim of this study was to examine relationship of physical fitness with frequency of participation in this checkup. The subjects had all attended at least one annual physical checkup from 2006 to 2018. Data from 1,804 initial checkups were used for analysis. At the checkups, age, gender, height, weight, body mass index (BMI), and bone mineral density (BMD) were recorded, and physical activity was measured. The average number of physical checkups per participant for 13 years was 2.4 (1–13). Daily exercise habits were found to be significantly associated with higher participation in physical checkups. Furthermore, between groups with low (1–5 times; <90th percentile of participants) and high (≥6 times) participation, weight and BMI were significantly higher, and BMD, grip strength, 10-m gait time, back muscle strength, and two-step test were all significantly lower in the group with lower frequency of participation in the checkup. In conclusions, our results show that frequency of participation in a voluntary annual physical checkup is significantly associated with physical fitness in middle-aged and elderly people.

DOI： 10.18999/nagjms.83.4.841

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Language：English   Publisher：Journal of Clinical Neuroscience  

Purpose: To quantify calcification in spinal meningiomas using Hounsfield unit (HU) values on CT, and to analyze the characteristics of cases with and without calcification and with different histologic subtypes. Methods: The subjects were 53 patients who underwent surgical resection of spinal meningioma between January 1999 and December 2019. Clinical and surgical data were collected, and all patients were examined neurologically preoperatively and at final follow-up using the modified McCormick scale and the American Spinal Injury Association scale. Calcification was quantified on CT of the spine prior to surgery. A HU value >60 was considered to indicate calcification. Results: The 53 patients (11 males, 42 females) were aged 62.4 ± 14.3 (range 19 to 91) years at surgery, and had a symptom duration of 10.8 ± 9.0 (1–36) months. The histological type was meningothelial in 35 cases, psammomatous in 13, and others in 5. The mean tumor volume was 1166 ± 350 (593–2176) mm3, and the mean HU value was 212.2 ± 192.8 (43–648). Forty cases (75%) had calcification (HU value > 60). HU values were significantly related to duration of symptoms (R = 0.590, p < 0.05) and significantly higher in psammomatous cases (p < 0.05). Cases with calcification had longer operative times and greater blood loss, and a significantly lower rate of neurological improvement. Conclusion: CT was effective for detecting calcification based on HU values. Detection of a HU value > 60 in spinal meningioma may be useful to narrow the differential diagnosis, evaluate the difficulty of resection, and improve intraoperative management, all of which may improve outcomes.

DOI： 10.1016/j.jocn.2021.04.019

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Language：English   Publisher：Modern Rheumatology  

Objectives: Improvement of life expectancy is increasingly important with the aging of society. The aim of the study was to compare physical performance in elderly people in two 3-year periods (2001–2003) and (2016–2018). Methods: The participants were healthy Japanese elderly adults who attended public health check-ups in Yakumo. Results for 10 m gait time, two-step test, back muscle strength, and grip strength were examined prospectively for participants in 2001–2003 (Group A: n = 488) and 2016–2018 (Group B: n = 309) by gender and age (65–74 and 75–84 years). Results: There were significant differences between Groups A and B for 10 m gait time (age 65–74: male: 5.6 vs. 5.2 s, female: 6.3 vs. 5.5 s; age 75–84: male: 6.1 vs. 5.5 s, female: 6.7 vs. 5.8 s; all p <.05) and two-step test (age 65–74: male: 1.41 vs. 1.48, female: 1.35 vs. 1.44; age 75–84: male: 1.32 vs. 1.41, female: 1.30 vs. 1.38; all p <.05), but not for back muscle strength or grip strength. Conclusion: Our results suggest a phenomenon of ‘overcoming locomotive syndrome’, in which physical performance changed by aging, including motor functions such as 10 m gait time and two-step test, has improved in the current population compared with a similar population from 15 years ago.

DOI： 10.1080/14397595.2021.1879413

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Language：English   Publisher：Nagoya Journal of Medical Science  

A 48-year-old female patient presented with discomfort in the front of the chest. Whole spinal X-ray revealed a thoracic curve of 52°, and thoracic computed tomography (CT) myelography and magnetic resonance imaging (MRI) showed that ossification of the posterior longitudinal ligament (OPLL) on the concave side of the apex vertebra (T9) had highly compressed the spinal cord. Cervical MRI also showed that the C4-C5 intervertebral disc herniation mildly compressed the spinal nerve. In concomitant surgery, the patient underwent cervical laminoplasty, in which OPLL was removed by decompressive laminectomy and posterior correction surgery.In patients with adult spinal deformity (ASD), asymmetric mechanical stress at the apex vertebra can cause various abnormal conditions. Long-term local mechanical stress on the concave side of the apex vertebra might have affected OPLL formation in the present case. This is the first report of a surgical case for an ossification located on the concave side of the apex vertebra in a patient with ASD. Mechanical stress at the concave side of the apex vertebra was suspected to be a cause of formation of OPLL.

DOI： 10.18999/nagjms.83.2.387

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Language：English   Publisher：Spine  

Study Design.A cross-sectional analysis using T1 slope (T1S) and C7 slope (C7S) in asymptomatic individuals.Objective.The aim of this study was to identify normative values, ranges of motion (ROMs), age-related changes in T1S and C7S, and correlation between the two slopes.Summary of Background Data.Few studies have reported age-related changes in the T1S and C7S angles. Additionally, studies investigating the effects of cervical position on these slopes are limited.Methods.A total of 388 asymptomatic subjects (162 males and 226 females) for whom T1S measurement was performed on radiographs were enrolled in the study. The T1S and C7S angles were measured using neutral radiography of the cervical spine. ROMs were assessed by measuring the difference in alignment in the neutral position, flexion, and extension.Results.The mean C7S and T1S angles were 19.6° (22.2° in males, 17.9° in females) and 24.0° (26.7° in men and 22.1° in women), respectively. The T1S angle was significantly greater than the C7S angle. Both the C7S and T1S angles significantly increased with age. The flexion ROM of C7S was higher than that of T1S, whereas no significant difference was detected between the extension ROMs of the two slopes. The flexion ROMs of the two slopes did not change, whereas the extension ROMs significantly increased with age. A significant positive correlation was observed between the C7S and T1S angles (r2 = 0.75).Conclusion.The normative values and age-related changes in C7S and T1S were analyzed. Both the C7S and T1S angles increased with age. The C7S angle was strongly correlated with the T1S angle, suggesting that C7S can substitute T1S on radiographic images.Level of Evidence: 3.

DOI： 10.1097/BRS.0000000000003813

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Language：English   Publisher：European Spine Journal  

Purpose: Tandem spinal stenosis (TSS) refers to coexisting lumbar and cervical canal stenosis. Evidence regarding whether cervical decompression improves lumbar symptoms in TSS is insufficient. Therefore, we determined the effectiveness of cervical decompression surgery for patients with lumbar spinal stenosis (LSS) and cervical spinal stenosis. Methods: The records of 64 patients with TSS experiencing lumbar symptoms who underwent cervical decompression surgery between April 2013 and July 2017 at a single institution were retrospectively reviewed. We categorized patients into the Non-improved (n = 20), Relapsed (n = 30), and Maintained-improvement (n = 14) groups according to the presence or absence of improvement and relapse in lower limb symptoms in TSS following cervical decompression surgeries. Results: Of 64 patients, 44 (69%) showed improved lower limb or low back symptoms, with 14 (22%) patients maintaining improvement. The preoperative cervical myelopathy-Japanese Orthopedic Association score and the preoperative number of steps determined using the 10-s step test were significantly lower in the Non-improved group than in the Maintained-improvement group. Receiver operating characteristic curve of preoperative 10-s step test results revealed 12 steps as a predictor for maintained improvement. Conclusion: The improvement of LSS symptoms following cervical decompression surgeries may be associated with the severity of cervical myelopathy as determined in clinical findings rather than in imaging findings. Patients with TSS having a 10-s step test result of < 12 steps were more likely to experience a relapse of lower limb symptoms following cervical decompression surgeries.

DOI： 10.1007/s00586-020-06693-0

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Language：Japanese   Publisher：Interdisciplinary Neurosurgery: Advanced Techniques and Case Management  

Study Design: A case report. Objective: To report a dangerous intraoperative complication of spinal instrumentation surgery. Summary of Background Data: Spinal instrumentation is indispensable for surgical treatment of degenerative spinal disorders. Revision surgeries in cases with severe osteoporosis involve high risks of intraoperative complications. Methods: We present a case of a 79-year-old female who underwent revision surgery for thoracolumbar deformity. She had a medical history of rheumatoid arthritis and severe osteoporosis due to long time steroid medication. In the pedicle screw replacement procedure, the implant fell into the abdominal cavity through the vertebrae, as confirmed by fluoroscopy. Results: An emergent surgical survey with intraoperative computed tomography revealed that the implant was buried in the abdominal wall. General surgeons performed abdominal surgery; ascending colon mesentery and ovarian vein injuries were repaired. The patient recovered without any permanent disorders and was discharged from the hospital on schedule. Conclusions: Although intraoperative pedicle screw drop into the abdominal cavity is rare, this complication could occur in cases with severe osteoporosis and a revision surgery accompanied by screw loosening. Therefore, preoperative detailed radiographic evaluation and meticulous attention during surgery are mandatory for treatment of patients with severe osteoporosis.

DOI： 10.1016/j.inat.2020.100943

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Language：English   Publisher：Journal of Clinical Neuroscience  

Most thoracic intradural extramedullary tumors (IDEMT) are benign lesions that are treated by gross total resection and spinal cord decompression. Intraoperative transcranial-motor evoked potential (Tc-MEP) monitoring is important for reducing postoperative neurological complications. The purpose of this study is to examine the characteristics of Tc-MEP waveforms in surgery for thoracic IDEMT resection based on location of the tumor relative to the spinal cord. The subjects were 56 patients who underwent surgery for thoracic IDEMT from 2010 to 2018. The waveform derivation rate for each lower muscle was examined at baseline and intraoperatively. 56 patients had a mean age of 61.7 years, and 21 (38%) were non-ambulatory before surgery. The tumors were schwannoma (n = 28, 50%), meningioma (n = 25, 45%), and neurofibroma (n = 3, 5%); and the lesions were dorsal (n = 29, 53%) and ventral (n = 27, 47%). There was a significantly higher rate of undetectable waveforms in all lower limb muscles in the ventral group compared to the dorsal group (15% vs. 3%, p < 0.05). In non-ambulatory cases, the derivation rate at baseline was significantly lower for ventral thoracic IDMETs (47% vs. 68%, p < 0.05). The abductor hallucis (AH) had the highest waveform derivation rate of all lower limb muscles in non-ambulatory cases with a ventral thoracic IDMET. Spinal cord compression by a ventral lesion may be increased, and this may be reflected in greater waveform deterioration. Of all lower limb muscles, the AH had the highest derivation rate, even in non-ambulatory cases with a ventral IDEMT, which suggests the efficacy of multichannel monitoring including the AH.

DOI： 10.1016/j.jocn.2020.11.045

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Language：English   Publisher：Journal of Neurosurgery: Spine  

OBJECTIVE Although increased signal intensity (ISI) on MRI is observed in patients with cervical spinal cord injury (SCI) without major bone injury, alterations in ISI have not been evaluated. The association between postoperative ISI and surgical outcomes remains unclear. This study elucidated whether or not the postoperative classification and alterations in MRI-based ISI of the spinal cord reflected the postoperative symptom severity and surgical outcomes in patients with SCI without major bone injury. METHODS One hundred consecutive patients with SCI without major bone injury (79 male and 21 female) with a mean age of 55 years (range 20–87 years) were included. All patients were treated with laminoplasty and underwent MRI pre- and postoperatively (mean 12.5 ± 0.8 months). ISI was classified into three groups on the basis of sagittal T2-weighted MRI: grade 0, none; grade 1, light (obscure); and grade 2, intense (bright). The neurological statuses were evaluated according to the Japanese Orthopaedic Association (JOA) scoring system and the American Spinal Injury Association Impairment Scale (AIS). RESULTS Preoperatively, 8 patients had grade 0 ISI, 49 had grade 1, and 43 had grade 2; and postoperatively, 20 patients had grade 0, 24 had grade 1, and 56 had grade 2. The postoperative JOA scores and recovery rate (RR) decreased significantly with increasing postoperative ISI grade. The postoperative ISI grade tended to increase with the postoperative AIS grade. Postoperative grade 2 ISI was observed in severely paralyzed patients. The postoperative ISI grade improved in 23 patients (23%), worsened in 25 (25%), and remained unchanged in 52 (52%). Patients with an improved ISI grade had a better RR than those with a worsened ISI grade. CONCLUSIONS Postoperative ISI reflected postoperative symptom severity and surgical outcomes. Alterations in ISI were seen postoperatively in 48 patients (48%) and were associated with surgical outcomes.

DOI： 10.3171/2020.6.SPINE20761

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Language：English   Publisher：Nagoya Journal of Medical Science  

The Joint Commission International (JCI) is a US-based organization that accredits and certifies hospitals worldwide. Among the requirements for accreditation, the JCI emphasizes continuous quality improvement (CQI) with regard to international patient safety goals (IPSGs). Our university hospital treats about 26,000 hospitalized patients and 600,000 outpatients annually, and our goal is patient safety in compliance with IPSGs. The purpose of this study is to examine the activities of orthopedic surgeons in preparation for JCI accreditation, including clear identification of patients, preoperative timeout and marking to ensure correct surgery, timely approval of CT/MRI reports, care with pain management, prevention of infection, setting of quality indicators and daily monitoring, and teamwork. Examiners from the JCI visited our hospital to review medical records and documents, and to interview patients, nurses and doctors. There were 1270 evaluation items covering 16 fields, including reviews of IPSGs, patient evaluation and care, infection prevention and control, and governance and leadership. Most importantly, the efforts of all the medical staff in our hospital in obtaining the first JCI accreditation among national university hospitals in Japan have promoted the safety and quality of medical care from the perspective of the patient

DOI： 10.18999/nagjms.83.1.87

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Language：English   Publisher：Spine  

Study Design.A retrospective analysis of magnetic resonance imaging (MRI) was conducted.Objective.This study aims to develop an automated system for the detection of spinal schwannoma, by employing deep learning based on object detection from MRI. The performance of the proposed system was verified to compare the performances of spine surgeons.Summary of Background Data.Several MRI scans were conducted for the diagnoses of patients suspected to suffer from spinal diseases. Typically, spinal diseases do not involve tumors on the spinal cord, although a few tumors may exist at the unexpectable level or without symptom by chance. It is difficult to recognize these tumors; in some cases, these tumors may be overlooked. Hence, a deep learning approach based on object detection can minimize the probability of overlooking these tumors.Methods.Data from 50 patients with spinal schwannoma who had undergone MRI were retrospectively reviewed. Sagittal T1- and T2-weighted magnetic resonance imaging (T1WI and T2WI) were used in the object detection training and for validation. You Only Look Once version3 was used to develop the object detection system, and its accuracy was calculated. The performance of the proposed system was compared to that of two doctors.Results.The accuracies of the proposed object detection based on T1W1, T2W1, and both T1W1 and T2W1 were 80.3%, 91.0%, and 93.5%, respectively. The accuracies of the doctors were 90.2% and 89.3%.Conclusion.Automated object detection of spinal schwannoma was achieved. The proposed system yielded a high accuracy that was comparable to that of the doctors.Level of Evidence: 4.

DOI： 10.1097/BRS.0000000000003749

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DOI： 10.31616/asj.2019.0374

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Language：English   Publisher：Journal of Clinical Neuroscience  

To perform spinal surgery safely, it is important to understand the risk factors, including factors that negatively influence intraoperative neuromonitoring (IONM). Transcranial motor evoked potentials (TcMEPs) are important in IONM. Therefore, we aimed to investigate whether muscle mass affects the waveforms of TcMEPs to understand the risk factors influencing TcMEPs. We enrolled 48 patients with thoracolumbar spinal diseases who underwent surgery at our facility between April 2015 and March 2018. Before surgery, the body composition, including muscle mass and fat mass, of all patients was measured using bioelectrical impedance analysis (BIA). During surgery, cranial stimulation under general anesthesia was used to derive TcMEPs, enabling us to measure the amplitude, using the control wave of the TcMEPs of the deltoid muscles and the abductor digiti minimi (ADM) muscles. We found a negative correlation between the amplitude of deltoid-muscle TcMEPs and muscle mass of the upper limb. The amplitude of deltoid-muscle TcMEPs did not correlate with the skeletal muscle index (SMI), muscle mass of the lower limb, or body fat mass. The amplitude of ADM-muscle TcMEPs did not correlate with SMI, muscle mass of any limb, or body fat mass. In conclusion, a larger muscle mass of the upper limb correlated with a lower amplitude of deltoid-muscle TcMEPs. By contrast, there was no correlation between the muscle mass of the upper limb and the amplitude of ADM-muscle TcMEPs. These findings suggest that TcMEPs of the ADM are less influenced by muscle mass and are more stable than those of the deltoid.

DOI： 10.1016/j.jocn.2020.10.004

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Language：English   Publisher：BioMed Research International  

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

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Language：English   Publisher：European Spine Journal  

Purpose: To identify age-related changes and the relationship between upper and lower cervical sagittal alignment and the range of motion (ROM). Methods: A total of 600 asymptomatic volunteers were enrolled. There were 50 males and 50 females in each decade of life between the third and the eighth. The O–C2 angle and the C2–7 angle were measured using the neutral radiographs of the cervical spine. ROM was assessed by measuring the difference in alignment in the neutral, flexion, and extension positions. Results: The mean O–C2 angle in the neutral position was 14.0° lordotic. The mean ROM of the O–C2 angle was 23.1°. The mean C2–7 angle in the neutral position was 14.3° lordotic. The mean ROM of the C2–7 angle was 56.0°. The O–C2 angle was 16.1° in the third decade and gradually decreased to 11.4° in the eighth decade. There were no significant age-related changes in the ROM of the O–C2 angle. The C2–7 angle was 7.2° in the third decade and gradually increased to 20.8° in the eighth decade, and the ROM gradually decreased with increasing age. Significant negative correlation was observed between O–C2 angle and C2–7 angle. Conclusion: The O–C2 angle gradually decreased and the C2–7 angle increased with age. The ROM of the O–C2 angle did not change, but the ROM of the C2–7 angle decreased with age. The upper and lower cervical spine showed different age-related changes.

DOI： 10.1007/s00586-020-06547-9

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Language：Japanese   Publisher：Asian Spine Journal  

Study Design: Retrospective study in a single center. Purpose: To examine denosumab persistence in patients of different ages with severe osteoporosis in Japan. Overview of Literature: Denosumab is an antibody drug used for the treatment of osteoporosis. It is mainly used in patients with severe osteoporosis who might have high motivation for treatment, and the need for only semi-annual subcutaneous injection might improve the continuation rate. However, no English-language articles have reported on denosumab persistence in the Japanese population, including young people, despite the importance of this issue in a super-aging society. Methods: The subjects started treatment with subcutaneous denosumab in our department from July 2013 until December 2017. Persistence rates were calculated using Kaplan-Meier curves. Patients were defined as "persistent" or "non-persistent" according to the use of therapy after 60 months. Results: The study included 101 patients (84 females) with a median follow-up period of 23.6±14.2 months. The persistence rate declined to 85.3%, 78.3%, 74.1%, 71.3%, and 69.3% at 12, 24, 36, 48, and 60 months, respectively. Age at the initiation of denosumab therapy differed significantly between non-persistent (n=31) and persistent (n=70) patients (81.3 vs. 72.8 years, p <0.01). Persistence was significantly lower in patients aged =80 years than in those aged <60 and 60-79 years (both p <0.01). The reasons for non-persistence of denosumab therapy were transfer to another hospital (n=13), interruption of outpatient visits (n=11), dental treatment (n=4), adverse events (n=2), and patient request (n=1). Conclusions: Persistence was significantly lower in patients aged =80 years than in patients of other ages, and strategies promoting persistence are needed for these elderly patients.

DOI： 10.31616/asj.2020.0230

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Language：English   Publisher：Nagoya Journal of Medical Science  

Aging of society has increased the incidence of physical disability. The goal of this study was to examine the physical ability of elderly people classified as having sarcopenia, presarcopenia, or dynapenia (a low muscle function without low muscle mass) in a community in Japan. The subjects were volunteers aged >60 years who were participants in a health checkup in Yakumo, Hokkaido and were in good general health. Demographic data were collected and physical performance tests were performed to measure grip strength, walking speed, back muscle strength, maximum stride length, and 3-m timed-up-and-go (3m TUG) time. A measurement of skeletal muscle mass was used as a basis for calculating the appendicular skeletal muscle index (aSMI). The rates of sarcopenia, presarcopenia, and dynapenia were 10%, 22%, and 8% in males (n=101, age 69.7±5.4 years), and 19%, 23%, and 13% in females (n=112, 68.5±5.9 years). Body mass index in subjects with dynapenia was significantly higher compared to that in subjects with sarcopenia and presarcopenia (p<0.01). Back muscle strength, maximum stride length and 3m TUG were similar in dynapenia and sarcopenia, but differed significantly with those in presarcopenia in both males and females without the influence of age (p<0.05). Further studies are needed to evaluate the benefits of dynapenia intervention programs and to explore the underlying pathophysiology of dynapenia.

DOI： 10.18999/nagjms.82.3.415

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DOI： 10.31616/asj.2019.0230

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Language：English   Publisher：Asian Spine Journal  

Purpose: We compared clinical and radiographical outcomes after lumbar decompression revision surgery for restenosis by lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF). Overview of Literature: Indirect lumbar decompression with LLIF was used to treat degenerative lumbar diseases requiring neural decompression. However, only a few studies have focused on the effectiveness of this technique for restenosis after lumbar decompression. Methods: We retrospectively investigated 52 cases involving lumbar interbody fusions for restenosis with spondylolisthesis after lumbar decompressions; these cases consisted of 15 patients who underwent indirect decompression with LLIF and posterior fixation and 37 patients who underwent the same procedure with PLIF. We compared Japanese Orthopaedic Association (JOA) scores and perioperative complications between groups. The cross-sectional areas of the thecal sac on magnetic resonance imaging were measured before, immediately after, and 2 years after surgery. We conducted statistical analyses using unpaired t-test and Fisher's exact tests, and a p-value <0.05 was considered statistically significant. Results: The operative time was significantly shorter in the LLIF group than in the PLIF group (115.3±33.6 min vs. 186.2±34.2 min, respectively; p <0.001). In addition, the intraoperative blood loss was significantly lower in the LLIF group than in the PLIF group (58.2±32.7 mL vs. 303.2±140.1 mL, respectively; p <0.001). We found two cases of transient lateral thigh weakness (13.3%) in the LLIF group and five cases of incidental durotomy, one case of deep infection, and one case of neurological deterioration in the PLIF group-resulting in a higher complication incidence (18.9%), although it did not reach (p =0.63). The JOA scores improved significantly in both groups. Conclusions: Indirect decompression using LLIF provided acceptable clinical and radiographical outcomes in patients with restenosis with spondylolisthesis after lumbar decompression; no revision-surgery-specific complications were found. Our results suggest that LLIF is a safe and minimally invasive procedure for revision surgery.

DOI： 10.31616/asj.2019.0194

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PubMed

Language：English   Publisher：Asian Spine Journal  

Study Design: A retrospective cohort study. Purpose: The purpose of this study was to investigate the prevalence and risk factors for S2 alar-iliac (SAI) screw loosening following lumbosacral fixation, with a minimum 2-year follow-up. Overview of Literature: Although SAI screws allow surgeons to perform lumbosacral fixation with a low profile and enhanced biomechanical strength, screw loosening following surgery can occur in some cases. However, few studies have investigated the prevalence and risk factors for SAI screw loosening. Methods: This retrospective study included 35 patients (mean age, 72.8±8.0 years; male, 10; female, 25) who underwent lumbosacral fixation using SAI screws with at least 2 years of follow-up. SAI screw loosening and L5-S bony fusion were assessed using computed tomography. The period for which the screws appeared loose and the risk factors for SAI screw loosening were investigated 2 years after surgery. Results: A total of 70 SAI screws and 70 S1 pedicle screws were inserted. Loosening was observed 0.5, 1, and 2 years after surgery in 17 (24.3%), 35 (50.0%), and 35 (50.0%) SAI screws, respectively. Bony fusion rate at L5-S was significantly lower in patients with SAI screw loosening than in those without screw loosening (65.0% vs. 93.3%, p=0.048). The score for SAI screw contact with the iliac cortical bone and the bony fusion rate at L5-S were significantly lower in the loosening group than in the non-loosening group (1.8±0.5 vs. 2.2±0.3, p<0.001, respectively). Postoperative pelvic incidence-lumbar lordosis was significantly higher in the loosening group than in the non-loosening group (7.9°±15.4° vs. 0.5°±8.7°, p=0.02, respectively). Conclusions: SAI screw loosening is closely correlated with pseudoarthrosis at L5-S. Appropriate screw insertion and optimal lumbar lordosis restoration are important to prevent postoperative complications related to SAI screws.

DOI： 10.31616/asj.2019.0127

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Scopus

PubMed

Language：English   Publisher：Spine  

Study Design.A prospective cohort study.Objective.The aim of this study was to investigate radiographical changes related to indirect decompression using lateral lumbar interbody fusion (LLIF) with posterior fixation.Summary of Background Data.Indirect lumbar decompression via LLIF is used to treat degenerative lumbar diseases requiring neural decompression. Although evidence suggests that thecal sac enlargement follows shortly after surgery, few studies have described the postoperative changes on MRIs.Methods.This study involved 102 patients who underwent indirect decompression at 136 levels, with LLIF and posterior fixation. Magnetic resonance imaging (MRIs) were collected preoperatively and several times postoperatively (over a 2-year period starting immediately after surgery). We then quantified the cross-sectional areas of the thecal sac and ligamentum flavum, as well as the anteroposterior diameter of disc bulging, and qualitatively assessed lumbar spinal stenosis according to a modified version of Schizas' classification [Grades A (mild) to C (severe)]. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) was used for the assessment of the clinical symptoms.Results.All changes were observable immediately after surgery, progressed over time, and were significantly different statistically at 2 years after surgery. The thecal sac was significantly larger (189% of preoperative; P < 0.0001), while the ligamentum flavum and disc bulge were significantly smaller [58.9% and 67.3% of preoperative (P < 0.001), respectively]. The number of patients with grade C (severe) lumbar stenosis also dropped significantly (preoperative, 17.6%; 2 years postoperative, 0%). There were no significant differences in JOABPEQ results at 6 months, 1 year, and 2 years postsurgery.Conclusion.Indirect decompression produces immediate positive results that continue to improve over time. The cross-sectional area of the thecal sac doubled by 2 years after surgery, and the ligamentum flavum cross-sectional area and disc bulging both shrank significantly. At the same time, however, postoperative radiographical improvements do not appear to correlate with clinical symptoms.

DOI： 10.1097/BRS.0000000000003180

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PubMed

Language：English   Publisher：Asian Spine Journal  

Study Design: Retrospective case-control study. Purpose: We aimed to compare radiologic outcomes between posterior (PLIF) and lateral lumbar interbody fusion (LLIF) in short-level spinal fusion surgeries. Overview of Literature: Although LLIF enables surgeons to insert large lordotic cages, it is unknown whether LLIF more effectively corrects local and global sagittal alignments compared with PLIF in short-level spinal fusion surgeries. Methods: Radiographic data acquired from patients with lumbar interbody fusion (≤3 levels) using PLIF or LLIF for degenerative lumbar diseases were analyzed. The following radiographic parameters were evaluated preoperatively and at 2 years postoperatively: segmental lordotic angle, disk height, lumbar lordosis (LL), pelvic tilt (PT), C7 sagittal vertical axis, and thoracic kyphosis (TK). Results: In total, 144 patients with PLIF (193 fused levels) and 101 with LLIF (159 fused levels) were included. Patients' backgrounds and preoperative radiographic parameters for any level of fusion did not differ significantly between PLIF and LLIF procedures. The LLIF group exhibited significantly greater changes at 1-level fusion compared to the PLIF group in the parameters of segmental lordotic angle (5.1°±5.8° vs. 2.1°±5.0°, p<0.001), disk height (4.2±2.3 mm vs. 2.2±2.0 mm, p<0.001), LL (7.8°±7.6° vs. 3.9°±8.6°, p=0.004), and PI-LL (-6.9°±6.8° vs. -3.6°±10.1°, p=0.03). While, a similar trend was observed regarding 2-level fusion, significantly greater changes were only observed in LL (12.1°±11.1° vs. 4.2°±9.1°, p=0.047) and PI-LL (-11.2°±11.3° vs. -3.0°±9.3°, p=0.043), PT (-6.4°±4.9° vs. -2.5°±5.3°, p=0.049) and TK (7.8°±11.8° vs. -0.3°±9.7°, p=0.047) in the LLIF group at 3-level fusion. Conclusions: LLIF provides significantly better local sagittal alignment than PLIF in 1- or 2-level fusion cases and improves spinopelvic alignment and local alignment for 3-level fusion cases. Thus, LLIF was demonstrated to be a useful lumbar interbody fusion technique, constituting a powerful tool for achieving sagittal realignment with minimal surgical invasiveness.

DOI： 10.31616/asj.2019.0011

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Scopus

PubMed

Language：English   Publisher：Asian Spine Journal  

Study Design: Prospective cohort study. Purpose: To identify factors that affect sagittal alignment correction in lateral lumbar interbody fusion (LIF) surgery for adult spinal deformity (ASD) and to investigate the degree of correction in each condition. Overview of Literature: LIF is a useful procedure for ASD, but the degree of correction can be affected by posterior osteotomy, intraoperative endplate injury, or anterior longitudinal ligament (ALL) rupture. Methods: Radiographical data for 30 patients who underwent LIF for ASD were examined prospectively. All underwent two-stage surgery (LIF followed by posterior fixation). Radiographical parameters were measured preoperatively, after LIF, and after posterior fixation; these included the segmental lordotic angle, lumbar lordosis (LL), and other sagittal alignment factors. Results: LL was corrected from 16.5°±16.7° preoperatively to 33.4°±13.8° after LIF (p<0.001) and then to 52.1°±7.9° following posterior fixation (p<0.001). At levels where Schwab grade 2 osteotomy was performed, the acquired segmental lordotic angles from the preoperative value to after posterior fixation and from after LIF to after posterior fixation were 19.5°±9.2° and 9.9°±3.9°, respectively. On average, 12.4° more was added than in cases without osteotomy. Endplate injury was identified at 21 levels (19.4%) after LIF, with a mean loss of 3.4° in the acquired segmental lordotic angle (5.3°±8.4° and 1.9°±5.9° without and with endplate injury, respectively). ALL rupture was identified at seven levels (6.5%), and on average 19.3° more was added in these cases between the preoperative and postoperative values than in cases without ALL rupture. Conclusions: LIF provides adequate sagittal alignment restoration for ASD, but the degree of correction is affected by grade 2 osteotomy, intraoperative endplate injury, and ALL rupture.

DOI： 10.31616/asj.2018.0275

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Scopus

PubMed

Language：English   Publisher：Asian Spine Journal  

Study Design: Prospective cohort study. Purpose: This study aimed to identify risk factors for unplanned second-stage decompression for postoperative neurological deficit after indirect decompression using lateral lumbar interbody fusion (LLIF) with posterior fixation. Overview of Literature: Indirect lumbar decompression with LLIF has been used as a minimally invasive alternative to direct decompression to treat degenerative lumbar diseases requiring neural decompression. However, evidence on the prevalence of neurological deficits caused by spinal canal stenosis after indirect decompression is limited. Methods: This study included 158 patients (mean age, 71.13±7.98 years; male/female ratio, 67/91) who underwent indirect decompression with LLIF and posterior fixation. Indirect decompression was performed at 271 levels (mean level, 1.71±0.97). Logistic regression analysis was used to identify the risk factors for postoperative neurological deficits. The variables included were age, sex, body mass index, presence of primary diseases, diabetes mellitus, preoperative motor deficit, levels operated on, preoperative severity of lumbar stenosis, and preoperative Japanese Orthopedic Association (JOA) score. Results: Postoperative neurological deficit due to spinal canal stenosis occurred in three patients (1.9%). Spinal stenosis due to hemodialysis (p < 0.001), ligament ossification (p < 0.001), presence of preoperative motor paralysis (p < 0.001), low JOA score (p=0.004), and severe canal stenosis (p=0.02) were significantly more frequent in the paralysis group. Conclusions: Severe preoperative canal stenosis and neurological deficit were identified as risk factors for postoperative neurological deterioration caused by spinal canal stenosis. Additionally, uncommon diseases, such as spinal stenosis due to hemodialysis and ligament ossification, increased the risk of postoperative neurological deficit; therefore, in such cases, indirect decompression is contraindicated.

DOI： 10.31616/asj.2018.0232

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Scopus

PubMed

Language：English   Publisher：Asian Spine Journal  

Study Design: Retrospective case-control study. Purpose: To compare surgical invasiveness and radiological outcomes between posterior lumbar interbody fusion (PLIF) and lateral lumbar interbody fusion (LLIF) for degenerative lumbar kyphosis. Overview of Literature: LLIF is a minimally invasive interbody fusion technique; however, few reports compared the clinical outcomes of conventional PLIF and LLIF for degenerative lumbar kyphosis. Methods: Radiographic data for patients who have undergone lumbar interbody fusion (≥3 levels) using PLIF or LLIF for degenerative lumbar kyphosis (lumbar lordosis [LL] < 20°) were retrospectively examined. The following radiographic parameters were retrospectively evaluated preoperatively and 2 years postoperatively: segmental lordotic angle, LL, pelvic tilt (PT), pelvic incidence (PI), C7 sagittal vertical axis, and T1 pelvic angle. Results: Nineteen consecutive cases with PLIF and 27 cases with LLIF were included. There were no significant differences in patients' backgrounds or preoperative radiographic parameters between the PLIF and the LLIF groups. The mean fusion level was 5.5±2.5 levels and 5.8±2.5 levels in the PLIF and LLIF groups, respectively (p=0.69). Although there was no significant difference in surgical times (p=0.58), the estimated blood loss was significantly greater in the PLIF group (p < 0.001). Two years postoperatively, comparing the PLIF and LLIF groups, the segmental lordotic angle achieved (7.4°±7.6° and 10.6°±9.4°, respectively; p=0.03), LL (27.8°±13.9° and 39.2°±12.7°, respectively; p=0.006), PI-LL (19.8°±14.8° and 3.1°±17.5°, respectively; p=0.002), and PT (22.6°±7.1° and 14.2°±13.9°, respectively; p=0.02) were significantly better in the LLIF group. Conclusions: LLIF provided significantly better sagittal alignment restoration in the context of degenerative lumbar kyphosis, with less blood loss.

DOI： 10.31616/asj.2018.0204

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PubMed

Language：Japanese   Publisher：株式会社医学書院  

DOI： 10.11477/mf.1436203933

PubMed

CiNii Research

Language：English   Publisher：The Japanese Society for Spine Surgery and Related Research  

<p>Introduction: Few studies have investigated the influence of cage subsidence patterns (intraoperative endplate injury or late-onset cage settling) on bony fusion and clinical outcomes in lateral interbody fusion (LIF). This retrospective study was performed to compare the fusion rate and clinical outcomes of cage subsidence patterns in LIF at one year after surgery.</p><p>Methods: Participants included 93 patients (aged 69.0±0.8 years; 184 segments) who underwent LIF with bilateral pedicle screw fixation. All segments were evaluated by computed tomography and classified into three groups: Segment E (intraoperative endplate injury, identified immediately postoperatively); Segment S (late-onset settling, identified at 3 months or later); or Segment N (no subsidence). We compared patient characteristics, surgical parameters and fusion status at 1 year for the three subsidence groups. Patients were classified into four groups: Group E (at least one Segment E), Group S (at least one Segment S), Group ES (both Segments E and S), or Group N (Segment N alone). Visual analog scales (VASs) and the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were compared for the four patient groups.</p><p>Results: 184 segments were classified: 31 as Segment E (16.8%), 21 as Segment S (11.4%), and 132 as Segment N (71.7%). Segment E demonstrated significantly lower bone mineral density (-1.7 SD of T-score, p=0.003). Segment S demonstrated a significantly higher rate of polyetheretherketone (PEEK) cages (100%, p=0.03) and a significantly lower fusion rate (23.8%, p=0.01). There were no significant differences in VAS or in any of the JOABPEQ domains among the four patient groups.</p><p>Conclusions: Intraoperative endplate injury was significantly related to bone quality, and late-onset settling was related to PEEK cages. Late-onset settling demonstrated a worse fusion rate. However, there were no significant differences in clinical outcomes among the subsidence patterns.</p>

DOI： 10.22603/ssrr.1.2017-0004

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Scopus

PubMed

CiNii Research

Language：English   Publisher：The Japanese Society for Spine Surgery and Related Research  

<p>Lateral approach spine surgery provides effective interbody stabilization, and correction and indirect neural decompression with minimal-incision and less invasive surgery compared with conventional open anterior lumbar fusion. It may also avoid the trauma to paraspinal muscles or facet joints found with transforaminal lumbar interbody fusion and posterior lumbar interbody fusion. However, because lateral approach surgery is fundamentally retroperitoneal approach surgery, it carries potential risk to intra- and retroperitoneal structures, as seen in a conventional open anterior approach. There is an innovative lateral approach technique that reveals different anatomical views; however, it requires reconsideration of the traditional surgical anatomy in more detail than a traditional open anterior approach. The retroperitoneum is the compartmentalized space bounded anteriorly by the posterior parietal peritoneum and posteriorly by the transversalis fascia. The retroperitoneum is divided into three compartments by fascial planes: anterior and posterior pararenal spaces and the perirenal space. Lateral approach surgery requires mobilization of the peritoneum and its content and accurate exposure to the posterior pararenal space. The posterior pararenal space is confined anteriorly by the posterior renal fascia, anteromedially by the lateroconal fascia, and posteriorly by the transversalis fascia. The posterior renal fascia, the lateroconal fascia or the peritoneum should be detached from the transversalis fascia and the psoas fascia to allow exposure to the posterior pararenal space. The posterior pararenal space, however, does not allow a clear view and identification of these fasciae as this relationship is variable and the medial extent of the posterior pararenal space varies among patients. Correct anatomical recognition of the retroperitoneum is essential to success in lateral approach surgery. Spine surgeons must be aware that the retroperitoneal membrane and fascia is multilayered and more complex than is commonly understood. Preoperative abdominal images would facilitate more efficient surgical considerations of retroperitoneal membrane and fascia in lateral approach surgery.</p>

DOI： 10.22603/ssrr.1.2017-0008

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Scopus

PubMed

CiNii Research