古矢 丈雄

STUDY DESIGN: Retrospective analysis of data collected across multiple centers. OBJECTIVE: To develop machine learning models for predicting neurological outcomes one month postoperatively in patients with metastatic spinal tumors undergoing surgery, and to identify key factors influencing neurological recovery. SUMMARY OF BACKGROUND DATA: The increasing prevalence of spinal metastases has led to a growing need for surgical intervention to address mechanical instability and neurological deficits. Predicting postoperative neurological status, as assessed by the Frankel classification, can provide valuable insights for surgical planning and patient counseling. Traditional prognostic models have shown limitations in capturing the complexity of neurological recovery patterns. METHODS: We analyzed data from 244 patients who underwent spinal surgery for metastatic disease across 38 institutions. The primary outcome was functional ambulation, defined as Frankel grades D or E at one month postoperatively. Four machine learning algorithms (Random Forest, XGBoost, LightGBM, and CatBoost) were used to build predictive models. Feature selection employed the Boruta algorithm and Variance Inflation Factor analysis to reduce multicollinearity. RESULTS: Among the 244 patients, the proportion of ambulatory patients (Frankel grades D or E) increased from 36.8% preoperatively to 63.1% at one month postoperatively. The Random Forest model achieved the highest area under the receiver operating characteristic curve (AUC-ROC) of 0.8516, followed by XGBoost (0.8351), CatBoost (0.8331), and LightGBM (0.8098). SHapley Additive exPlanations analysis identified preoperative Frankel classification, transfer ability, inflammatory markers (C-reactive protein, white blood cell-lymphocyte), and surgical timing as the most important predictors of postoperative outcomes. CONCLUSIONS: Machine learning models showed strong predictive performance in assessing postoperative neurological status for patients with metastatic spinal tumors. Key factors including preoperative neurological function, functional ability, and inflammation markers significantly influenced outcomes. These findings could inform surgical decision-making and help set realistic postoperative expectations while potentially improving patient care through more accurate outcome prediction.

PURPOSE: Cervical spine injuries in the elderly (defined as individuals aged 65 years and older) are increasing, often resulting from falls and minor trauma. Prognosis varies widely, influenced by multiple factors. This study aimed to develop a deep-learning-based predictive model for post-injury outcomes. METHODS: This study analyzed a nationwide dataset from the Japan Association of Spine Surgeons with Ambition, comprising 1512 elderly patients (aged 65 years and older) with cervical spine injuries from 2010 to 2020. Deep learning predictive models were constructed for residence, mobility, and the American Spinal Injury Association Impairment Scale (AIS). The model's performance was compared with that of a traditional statistical analysis. RESULTS: The deep-learning model predicted the residence and AIS outcomes with varying accuracies. The highest accuracy was observed in predicting residence one year post-injury. The model also identified that the AIS score at discharge was significantly predicted by upper extremity trauma, mobility, and elbow extension strength. The deep learning model highlighted factors, such as upper extremity trauma, that were not considered significant in the traditional statistical analysis. CONCLUSION: Our deep learning-based model offers a novel method for predicting outcomes following cervical spine injuries in the elderly population. The model is highly accurate and provides additional insights into potential prognostic factors. Such models can improve patient care and individualize future interventions.

OBJECTIVE: Instrumentation surgery in combination with radiotherapy (RT) is one of the key management strategies for patients with spinal metastases. However, the use of materials can affect the RT dose delivered to the tumor site and surrounding tissues, as well as hinder optimal postoperative tumor evaluation. The association of the preoperative Spine Instability Neoplastic Score (SINS) with the need for spinal stabilization and life expectancy are unclear. This multicenter prospective study aimed to investigate the current situation and make recommendations regarding the choice of surgical procedure based on the preoperative SINS and prospectively collected postoperative patient-reported outcomes (PROs). METHODS: The study prospectively included 317 patients with spinal metastases who underwent palliative surgery and had a minimum follow-up period of 6 months. The survey items included SINS, patient background, and clinical data including surgical procedure, history of RT, prognosis, and PROs (i.e., the visual analog scale score, Faces Scale, Barthel Index, Vitality Index, and 5-level EQ-5D health survey) at baseline, and at 1 and 6 months after surgery. The association of preoperative SINS with life expectancy, PROs, and surgical procedures was examined using statistical analysis. RESULTS: Preoperative SINS (three categories) had no association with life expectancy. All PROs evaluated in the study improved up to 6 months after surgery. Pain categories (visual analog scale score and/or Faces Scale) at baseline were correlated with preoperative SINS. As many as 90.9% of enrolled patients underwent fusion surgery, and even in SINS 0-6 cases, implants were used in 64.3% of patients. Postoperative RT was performed in 42.9% of the patients. However, prospective assessments of PROs showed no significant difference between surgical procedures (with and without fusion) in patients with SINS 0-9. In addition, no cases required conversion from noninstrumentation surgery to fusion surgery. CONCLUSIONS: Although the choice of surgical procedure should be made on a case-by-case basis on the NOMS (neurological, oncological, mechanical, and systemic) framework, careful consideration is required to determine whether spinal stabilization is needed in patients with SINS ≤ 9, considering the patient's background and the plan for postoperative adjuvant therapy.

INTRODUCTION: Elderly patients have a higher frequency of upper cervical fractures caused by minor trauma; nevertheless, the clinical differences between mid- and lower-cervical (C6-C7) injuries are unclear. The aim of this study was to compare the epidemiology of lower- and mid-cervical injuries in the elderly. METHODS: This multicenter, retrospective study included 451 patients aged 65 years or older who had mid- or lower-cervical fractures/dislocations. Patients' demographic and treatment data were examined and compared based on mid- and lower-cervical injuries. RESULTS: There were 139 patients (31%) with lower-cervical injuries and 312 (69%) with mid-cervical injuries. High-energy trauma (60% vs. 47%, p=0.025) and dislocation (55% vs. 45%, p=0.054) were significantly experienced more often by elderly patients with lower-cervical injuries than by patients with mid-cervical injuries. Although the incidence of key muscle weakness at the C5 to T1 levels were all significantly lower in patients with lower-cervical injuries than those with mid-cervical injuries, impairments at C5 occurred in 49% of them, and at C6, in 65%. No significant differences were found in the rates of death, pneumonia, or tracheostomy requirements, and no significant differences existed in ambulation or ASIA impairment scale grade for patients after 6 months of treatment. CONCLUSIONS: Elderly patients with lower-cervical fractures/dislocations were injured by high-energy trauma significantly more often than patients with mid-cervical injuries. Furthermore, half of the patients with lower-cervical injuries had mid-cervical level neurological deficits with a relatively high rate of respiratory complications.

STUDY DESIGN: Retrospective study. OBJECTIVES: To investigate the impact of diabetes mellitus on neurological recovery and determine the relationship between moderate-severe diabetes and neurological recovery in patients with cervical spinal cord injury (CSCI) without bone injury. METHODS: A retrospective study was conducted on 389 consecutive patients aged ≥65 years with CSCI without bone injury across 33 medical institutes. The patients were divided into a nondiabetic group (n = 270) and a diabetic group (n = 119). Neurological outcomes were compared between the two groups through propensity score matching. The impact of moderate-severe diabetes (defined as hemoglobin A1c ≥ 7.0% or requiring insulin treatment) on neurological recovery was evaluated through multiple linear regression analysis. RESULTS: Propensity score matching revealed no significant differences between the diabetic and nondiabetic groups in terms of American Spinal Injury Association (ASIA) impairment scale grade and mean total ASIA motor scores (AMS) at 6 months post-injury. Multiple linear regression analysis indicated that age on admission (B = -0.34; 95% confidence interval [CI], -0.59 to -0.08; P = 0.01), dementia (B = -16.50; 95% CI, -24.99 to -8.01; P < 0.01), and baseline total AMS (B = -0.62; 95% CI, -0.72 to -0.51; P < 0.01) were negative predictors of neurological recovery at 6 months post-injury. The presence of moderate-severe diabetes did not influence neurological recovery at 6 months post-injury. CONCLUSIONS: Diabetic patients with CSCI without bone injury achieved improvements in neurological function comparable to those of nondiabetic patients. Moderate-severe diabetes did not affect neurological recovery in patients with CSCI without bone injury.

STUDY DESIGN: Prospective multicenter study. OBJECTIVES: Palliative surgery is crucial for maintaining the quality of life (QOL) in patients with spinal metastases. This study aimed to compare the short-term outcomes of QOL after palliative surgery between patients with metastatic spinal tumors at different segments. METHODS: We prospectively compared the data of 203 patients with spinal metastases at 2-3 consecutive segments who were divided into the following three groups: cervical, patients with cervical spine lesions; thoracic, patients with upper-middle thoracic spine lesions; and TL/L/S, patients with lesions at the thoracolumbar junction and lumbar and sacral regions. Preoperative and postoperative EuroQol 5-dimension (EQ5D) 5-level were compared. RESULTS: All groups exhibited improvement in the Frankel grade, performance status, pain, Barthel index, EQ5D health state utility value (HSUV), and EQ5D visual analog scale (VAS) postoperatively. Although preoperative EQ5D HSUVs did not significantly differ between the groups (cervical, 0.461 ± 0.291; thoracic, 0.321 ± 0.292; and TL/L/S, 0.376 ± 0.272), the thoracic group exhibited significantly lower postoperative EQ5D HSUVs than the other two groups (cervical, 0.653 ± 0.233; thoracic, 0.513 ± 0.252; and TL/L/S, 0.624 ± 0.232). However, postoperative EQ5D VAS was not significantly different between the groups (cervical, 63.4 ± 25.8; thoracic, 54.7 ± 24.5; and TL/L/S, 61.7 ± 21.9). CONCLUSIONS: Palliative surgery for metastatic spinal tumors provided comparable QOL improvement, irrespective of the spinal segment involved. Patients with upper and middle thoracic spinal metastases had poorer QOL outcomes than those with metastases in other segments; however, sufficient QOL improvement was achieved.

INTRODUCTION: For older adults, dysphagia is a serious problem that can occur after spinal cord injury (SCI), but its risk factors are unclear. This study aimed to identify risk factors for dysphagia in elderly patients (≥65 years) with cervical SCI. METHODS: This multicenter study included 707 patients with cervical SCI (mean age 75.3 years). Univariate and multivariate analyses were conducted for patient characteristics and geriatric nutritional risk index (GNRI). RESULTS: Dysphagia occurred in 69 patients (9.8%). The significant factors were as follows: male sex (odds ratio [OR] 3.43), GNRI <92 (1.83), dementia (2.94), fracture (3.40), complete paralysis (3.61), anterior surgery (3.74), and tracheostomy (17.06). Age was not identified as a risk factor. CONCLUSIONS: Low GNRI before injury was one of the independent risk factors for dysphagia after geriatric cervical SCI. GNRI represents the comprehensive nutritional status of the elderly and reflects feeding function and its recovery capacity.

OBJECTIVE: This study aimed to elucidate postoperative outcomes in patients with spinal metastases of prostate cancer, with a focus on patient-oriented assessments. METHODS: This was a prospective multicenter registry study involving 35 centers. A total of 413 patients enrolled in the Japanese Association for Spine Surgery and Oncology Multicenter Prospective Study of Surgery for Metastatic Spinal Tumors were evaluated for inclusion. The eligible patients were followed for at least 1 year after surgery. The Frankel Classification, Eastern Cooperative Oncology Group Performance Status, visual analog scale for pain, face scale, Barthel Index, vitality index, indications for oral pain medication, and the EQ-5D-5L questionnaire were used for evaluating functional status, activities of daily living, and patient motivation. RESULTS: Of the 413 eligible patients, 41 with primary prostate cancer were included in the study. The patient-oriented assessments indicated that the patients experienced postoperative improvements in quality of life and motivation in most items, with the improvements extending for up to 6 months. More than half of the patients with Frankel classifications B or C showed improved neurological function at 1 month after surgery, and most patients presented maintained or improved their classification at 6 months. CONCLUSION: Surgical intervention for spinal metastases of prostate cancer significantly improved neurological function, quality of life, and motivation of the patients. Consequently, our results support the validity of surgical intervention for improving the neurological function and overall well-being of patients with spinal metastases of prostate cancer.

STUDY DESIGN: A retrospective analysis. OBJECTIVE: This research sought to develop a predictive model for surgical outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL) using deep learning and machine learning (ML) techniques. SUMMARY OF BACKGROUND DATA: Determining surgical outcomes assists surgeons in communicating prognosis to patients and setting their expectations. Deep learning and ML are computational models that identify patterns from large datasets and make predictions. METHODS: Of the 482 patients, 288 patients were included in the analysis. A minimal clinically important difference (MCID) was defined as gain in Japanese Orthopaedic Association (JOA) score of 2.5 points or more. The predictive model for MCID achievement at 1 year post-surgery was constructed using patient background, clinical symptoms, and preoperative imaging features (x-ray, CT, MRI) analyzed via LightGBM and deep learning with RadImagenet. RESULTS: The median preoperative JOA score was 11.0 (IQR: 9.0-12.0), which significantly improved to 14.0 (IQR: 12.0-15.0) at 1 year after surgery (P < 0.001, Wilcoxon signed-rank test). The average improvement rate of the JOA score was 44.7%, and 60.1% of patients achieved the MCID. Our model exhibited an area under the receiver operating characteristic curve of 0.81 and the accuracy of 71.9% in predicting MCID at 1 year. Preoperative JOA score and certain preoperative imaging features were identified as the most significant factors in the predictive models. CONCLUSION: A predictive ML and deep learning model for surgical outcomes in OPLL patients is feasible, suggesting promising applications in spinal surgery. LEVEL OF EVIDENCE: 4.

STUDY DESIGN: Multicenter, prospective registry study. OBJECTIVE: To clarify minimal clinically important differences (MCIDs) for surgical interventions for spinal metastases, thereby enhancing patient care by integrating quality of life (QoL) assessments with clinical outcomes. SUMMARY OF BACKGROUND DATA: Despite its proven usefulness in degenerative spinal diseases and deformities, the MCID remains unexplored regarding surgery for spinal metastases. METHODS: This study included 171 (out of 413) patients from the multicenter "Prospective Registration Study on Surgery for Metastatic Spinal Tumors" by the Japan Association of Spine Surgeons. These were evaluated preoperatively and at 6 months postoperatively using the Face scale, EuroQol-5 Dimensions-5 Levels (EQ-5D-5L), including the visual analog scale (VAS), and performance status. The MCIDs were calculated using an anchor-based method, classifying participants into the improved, unchanged, and deteriorated groups based on the Face scale scores. Focusing on the improved and unchanged groups, the change in the EQ-5D-5L values from before to after treatment was analyzed, and the cutoff value with the highest sensitivity and specificity was determined as the MCID through receiver operating characteristic curve analysis. The validity of the MCIDs was evaluated using a distribution-based calculation method for patient-reported outcomes. RESULTS: The improved, unchanged, and deteriorated groups comprised 121, 28, and 22 participants, respectively. The anchor-based MCIDs for the EQ-5D-5L index, EQ-VAS, and domains of mobility, self-care, usual activities, pain/discomfort, and anxiety/depression were 0.21, 15.50, 1.50, 0.50, 0.50, 0.50, and 0.50, respectively; the corresponding distribution-based MCIDs were 0.17, 15,99, 0.77, 0.80, 0.78, 0.60, and 0.70, respectively. CONCLUSION: We identified MCIDs for surgical treatment of spinal metastases, providing benchmarks for future clinical research. By retrospectively examining whether the MCIDs are achieved, factors favoring their achievement and risks affecting them can be explored. This could aid in decisions on surgical candidacy and patient counseling.

This retrospective cohort study established malnutrition's impact on mortality and neurological recovery of older patients with cervical spinal cord injury (SCI). It included patients aged ≥ 65 years with traumatic cervical SCI treated conservatively or surgically. The Geriatric Nutritional Risk Index was calculated to assess nutritional-related risk. Overall, 789 patients (mean follow-up: 20.1 months) were examined and 47 had major nutritional-related risks on admission. One-year mortality rate, median survival time, neurological recovery, and activities of daily living (ADL) at 1 year post-injury were compared between patients with major nutrition-related risk and matched controls selected using 1:2 propensity score matching to adjust for age, pre-traumatic neurological impairment, and activity. In the Kaplan-Meier analysis, the median survival times were 44.9 and 76.5 months for patients with major nutrition-related risk and matched controls, respectively (p = 0.015). Matched controls had more individuals with a neurological improvement of American Spinal Injury Association Impairment Scale ≥ 1 grade (p = 0.039) and independence in ADL at 1 year post-injury than patients with major nutrition-related risk (p < 0.05). In conclusion, 6% of older patients with cervical SCI had major nutrition-related risks; they showed a significantly higher 1 year mortality rate, shorter survival time, poorer neurological improvement, and lower ADL at 1 year post-injury than matched controls.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To define the prognosis and predictive factors for neurological improvement in older patients with incomplete spinal cord injury (SCI) of American Spinal Injury Association Impairment Scale grade C (AIS-C). SETTINGS: Multi-institutions in Japan. METHODS: We included patients aged ≥65 years with traumatic SCI of AIS-C who were treated conservatively or surgically with >3 follow-up months. To identify factors related to neurological improvement, patients were divided into three groups according to their neurological status at the final follow-up, with univariate among-group comparisons of demographics, radiographic, and therapeutic factors. Significant variables were included in the multivariate logistic regression analysis. RESULTS: Overall, 296 older patients with SCI of AIS-C on admission were identified (average age: 75.2 years, average follow-up: 18.7 months). Among them, 190 (64.2%) patients improved to AIS-D and 21 (7.1%) patients improved to AIS-E at final follow-up. There were significant among-group differences in age (p = 0.026), body mass index (p = 0.007), status of pre-traumatic activities of daily living (ADL) (p = 0.037), and serum albumin concentrations (p = 0.011). Logistic regression analysis showed no significant differences in variables in the stratified group of patients who improved to AIS-D. Meanwhile, serum albumin was a significant variable in patients who improved to AIS-E (p = 0.026; OR: 6.20, pre-traumatic ADL was omitted due to data skewness). CONCLUSIONS: Most older patients with incomplete AIS-C SCI demonstrated at least 1 grade of neurological improvement. However, <10% of patients achieved complete recovery. Key predictors of complete recovery were high serum albumin levels on admission and independent pre-traumatic ADL. SPONSORSHIP: No funding was received for this study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: The effectiveness of early surgery for cervical spinal injury (CSI) has been demonstrated. However, whether early surgery improves outcomes in the elderly remains unclear. This study investigated whether early surgery for CSI in elderly affects complication rates and neurological outcomes. METHODS: This retrospective multicenter study included 462 patients. We included patients with traumatic acute cervical spinal cord injury aged ≥65 years who were treated surgically, whereas patients with American Spinal Injury Association (ASIA) Impairment Scale E, those with unknown operative procedures, and those waiting for surgery for >1 month were excluded. The minimum follow-up period was 6 months. Sixty-five patients (early group, 14.1%) underwent surgical treatment within 24 hours, whereas the remaining 397 patients (85.9%) underwent surgery on a standby basis (delayed group). The propensity score-matched cohorts of 63 cases were compared. RESULTS: Patients in the early group were significantly younger, had significantly more subaxial dislocations (and fractures), tetraplegia, significantly lower ASIA motor scores, and ambulatory abilities 6 months after injury. However, no significant differences in the rate of complications, ambulatory abilities, or ASIA Impairment Scale scores 6 months after injury were observed between the matched cohorts. At 6 months after injury, 61% of the patients in the early group (25% unsupported and 36% supported) and 53% of the patients in the delayed group (34% unsupported and 19% supported) were ambulatory. CONCLUSIONS: Early surgery is possible for CSI in elderly patients as the matched cohort reveals no significant difference in complication rates and neurological or ambulatory recovery between the early and delayed surgery groups.

BACKGROUND: Cervicobrachial pain frequently affects the quality of life (QOL) of the general public and has a significant economic impact on the health care systems of various countries. There are a number of treatment options for this disease, including widely-used drug therapy, but the effectiveness of each option is indeterminate, and there have been no published cost-effectiveness analysis studies so far. This prospective observational study aimed to examine the cost-effectiveness of drug treatment for cervicobrachial symptoms. METHODS: A 6-month medication regimen for each of five frequently-prescribed drugs for cervicobrachial symptoms was administered to 322 patients at 24 centers in Japan. Outcome measures, including of the EuroQol Group 5D, Short Form-8, and Visual Analog Scale (VAS), were investigated at baseline and every month thereafter. Incremental cost-effectiveness ratios (ICERs) of the drug cost to quality-adjusted life years (QALYs) were calculated. A stratified analysis of patient characteristics was also performed to identify baseline factors potentially affecting cost-effectiveness. RESULTS: The ICER of entire drug treatment for cervicobrachial symptoms was 7,491,640 yen. Compared with the reference willingness-to-pay, the ICER was assumed to not be cost-effective. A certain number of QALYs were gained during the first 3 months after the treatment intervention, but almost no QALYs were gained during the following 3 months. Stratified analysis showed that cost-effectiveness was extremely low for patients with high baseline VAS and high QOL. CONCLUSIONS: The available medications for cervicobrachial symptoms did not have excellent cost-effectiveness. Although a certain number of QALYs were gained during the first 3 months after medication, no QALYs were gained in the latter half of the study period, suggesting that it is not advisable to continue the medication needlessly. LEVEL OF EVIDENCE: II, prospective cohort study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To investigate the treatments of the geriatric population with hangman's fractures using a multicenter database under the Japan Association of Spine Surgeons with Ambition (JASA). METHODS: The multicenter database included data from 1512 patients. We employed the Levine and Edwards classification for categorizing hangman's fractures. The study incorporated epidemiological data, including the prevalence of hangman's fractures, patient age, and follow-up duration. Bony fusion rates and length of hospitalization were recorded for Type I and Type II fractures, and the degree of neurological impairment was assessed. RESULTS: Hangman's fractures represented 62 cases, accounting for 7.4% of all cervical spine injuries. The patients had an average age of 76.6 ± 6.5 years, and the mean duration of follow-up was 21.5 ± 23.6 months. The study found that the bony fusion rate for hangman's fractures in the geriatric population was 88.9%. Surgical treatment was associated with a shorter hospitalization period for Type II fractures compared to conservative treatment. Thirteen cases of hangman's fractures in the geriatric population, accounting for 21%, were complicated by spinal cord injury. CONCLUSIONS: This is the largest study to date on hangman's fractures in geriatric population ≥65 years. Type I and Type II fractures, according to the Levine and Edwards classification, had a bony fusion rate of up to 90%. In patients with Type II fractures, surgical treatment led to a shorter initial hospital stay. Geriatric patients are at risk of spinal cord injury due to hangman's fractures.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: To investigate the effect of preoperative symptom duration on neurological recovery for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: The optimal timing to perform surgery in the setting of cervical OPLL remains unknown. It is important to know the influence of symptom duration on postoperative outcomes to facilitate discussions regarding the timing of surgery. PATIENTS AND METHODS: The study included 395 patients (291 men and 104 women; mean age, 63.7 ± 11.4 yr): 204 were treated with laminoplasty, 90 with posterior decompression and fusion, 85 with anterior decompression and fusion, and 16 with other procedures. The Japanese Orthopedic Association (JOA) score and patient-reported outcomes of the JOA Cervical Myelopathy Evaluation Questionnaire were used to assess clinical outcomes preoperatively and 2 years after surgery. Logistic regression analysis was used to identify factors associated with the achievement of minimum clinically important difference (MCID) after surgery. RESULTS: The recovery rate was significantly lower in the group with symptom duration of ≥5 years compared with the groups with durations of <0.5 years, 0.5 to 1 year, and 1 to 2 years. Improvement of JOA Cervical Myelopathy Evaluation Questionnaire in the upper extremity function score ( P < 0.001), lower extremity function ( P = 0.039), quality of life ( P = 0.053), and bladder function ( P = 0.034) were all decreased when the symptom duration exceeded 2 years. Duration of symptoms ( P = 0.001), age ( P < 0.001), and body mass index ( P < 0.001) were significantly associated with the achievement of MCID. The cutoff value we established for symptom duration was 23 months (area under the curve, 0.616; sensitivity, 67.4%; specificity, 53.5%). CONCLUSIONS: Symptom duration had a significant impact on neurological recovery and patient-reported outcome measures in this series of patients undergoing surgery for cervical OPLL. Patients with symptom duration exceeding 23 months may be at greater risk of failing to achieve MCID after surgery. LEVEL OF EVIDENCE: 3.

Platelet-rich plasma (PRP) promotes bone union through osteoinduction. We investigated whether adding demineralized bone matrix (DBM), derived naturally from biomaterial and with various growth factors, for osteoconductivity and bone marrow fluid for osteogenesis results in different bone unions. Eight-week-old male Sprague-Dawley rats were divided into four groups of five based on transplantation material: sham control (C group); DBM alone (D group); DBM + PRP (DP group); and DBM + PRP + bone marrow fluid (DPB group). After posterolateral fusion at L3-5, postoperative weekly CT imaging determined average number of bone union in facet joints (4 joints × 5 animals = 20 joints) and bone formation. Pathological evaluation and bone strength were assessed using 3-point bending two weeks postoperatively. Facet joint bone union at four weeks postoperatively was 4/20 (20%, DP group) and 8/20 (40%, DPB group) joints. Six weeks postoperatively, it was 7/20 (35%, D group), 12/20 (60%, DP group), and 16/20 (80%, DPB group). Eight weeks postoperatively, it was 13/20 (65%, D group), 17/20 (85%, DP group), and 20/20 (100%, DPB group), suggesting that DPB > DP > D > C. Bone formation and bone strength showed a similar DPB > DP > D > C group trend. Adding PRP and bone marrow fluid to DBM promotes bone union and strength.

STUDY DESIGN: A prospective multicenter study. OBJECTIVE: To investigate the incidence of loss of cervical lordosis after laminoplasty for cervical ossification of the posterior longitudinal ligament (OPLL). We also sought to determine associated risk factors and the relationship with patient-reported outcomes. SUMMARY OF BACKGROUND DATA: Loss of cervical lordosis is a sequalae often observed after laminoplasty, which may adversely impact surgical outcomes. Cervical kyphosis, especially in OPLL, is associated with reoperation, but risk factors and relationship to postoperative outcomes remain understudied at this time. METHODS: This study was conducted by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. We included 165 patients who underwent laminoplasty and completed Japanese Orthopaedic Association (JOA) score or Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaires (JOACMEQ), as well as visual analog scales (VAS) for pain, with imaging. The participants were divided into two groups: those with loss of cervical lordosis of>10° or 20° after surgery and those without loss of cervical lordosis. A paired t-test was applied to evaluate the association between changes in cervical spinal angles, ROM, and cervical JOA and VAS scores before and at 2 years postoperatively. Mann-Whitney U-test was used for JOACMEQ. RESULTS: Postoperative loss of cervical lordosis>10° and>20° was observed in 32 (19.4%) and 7 (4.2%), respectively. JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small extension range of motion (eROM) was significantly associated with postoperative loss of cervical lordosis, and the cutoff values of eROM were 7.4° [area under the curve (AUC): 0.76] and 8.2° (AUC: 0.92) for loss of cervical lordosis>10° and>20°, respectively. A large occupation ratio of OPLL was also associated with loss of cervical lordosis, with a cutoff value of 39.9% (AUC: 0.94). Laminoplasty resulted in functional improvement in most patient-reported outcomes; however, neck pain and bladder function tended to become worse postoperatively in cases with postoperative loss of cervical lordosis>20°. CONCLUSION: JOA, JOACMEQ, and VAS scores were not significantly different between those with, and without, loss of cervical lordosis. Preoperative small eROM and large OPLL may represent factors associated with loss of cervical lordosis after laminoplasty in patients with OPLL.

STUDY DESIGN: Retrospective study. PURPOSE: To compare the radiographic risk factors for decreased cervical lordosis (CL) after laminoplasty, focusing on the difference between cervical spondylotic myelopathy (CSM) and cervical ossification of the posterior longitudinal ligament (C-OPLL). OVERVIEW OF LITERATURE: A few reports compared the risk factors for decreased CL between CSM and C-OPLL although these two pathologies have their characteristics. METHODS: This study included 50 patients with CSM and 39 with C-OPLL who underwent multi-segment laminoplasty. Decreased CL was defined as the difference between preoperative and 2-year postoperative neutral C2-7 Cobb angles. Radiographic parameters included preoperative neutral C2-7 Cobb angles, C2-7 sagittal vertical axis (SVA), T1 slope (T1S), dynamic extension reserve (DER), and range of motion. The radiographic risk factors were investigated for decreased CL in CSM and C-OPLL. Additionally, the Japanese Orthopedic Association (JOA) score was assessed preoperatively and 2 years postoperatively. RESULTS: C2-7 SVA (p =0.018) and DER (p =0.002) were significantly correlated with decreased CL in CSM, while C2-7 Cobb angle (p =0.012) and C2-7 SVA (p =0.028) were correlated with decreased CL in C-OPLL. Multiple linear regression analysis revealed that greater C2-7 SVA (B =0.22, p =0.026) and small DER (B =-0.53, p =0.002) were significantly associated with decreased CL in CSM. By contrast, greater C2-7 SVA (B =0.36, p =0.031) was significantly associated with decreased CL in C-OPLL. The JOA score significantly improved in both CSM and C-OPLL (p <0.001). CONCLUSIONS: C2-7 SVA was associated with a postoperative decreased CL in both CSM and C-OPLL, but DER was only associated with decreased CL in CSM. Risk factors for decreased CL slightly differed depending on the etiology of the condition.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: The purpose of this study was to compare the prognosis of elderly patients with injuries related to cervical diffuse idiopathic skeletal hyperostosis (cDISH) to matched control for each group, with and without fractures. METHODS: The current multicenter study was a retrospective analysis of 140 patients aged 65 years or older with cDISH-related cervical spine injuries; 106 fractures and 34 spinal cord injuries without fracture were identified. Propensity score-matched cohorts from 1363 patients without cDISH were generated and compared. Logistic regression analysis was performed to determine the risk of early mortality for patients with cDISH-related injury. RESULTS: Patients with cDISH-related injuries with fracture did not differ significantly in the incidence of each complication and ambulation or severity of paralysis compared to matched controls. In patients with cDISH-related injury without fracture, those who were nonambulatory at discharge comprised 55% vs 34% of controls, indicating significantly poorer ambulation in those with cDISH-related injuries (P = .023). There was no significant difference in the incidence of complications and ambulation or paralysis severity at 6 months as compared with controls. Fourteen patients died within 3 months. Logistic regression analysis identified complete paralysis (odds ratio [OR] 36.99) and age (OR 1.24) as significant risk factors for mortality. CONCLUSIONS: The current study showed no significant differences in the incidence of complications, ambulation outcomes between patients with cDISH-related injury with fracture and matched controls, and that the ambulation at discharge for patients with cDISH-related injury without fractures were significantly inferior to those of matched controls.

Background In recent years, advances in the treatment of malignant tumors have improved life expectancy and diversified treatment options. However, maintaining high activities of daily living in patients is essential for appropriately treating the primary disease, and interventions for patients with impaired motor function will lead to improved quality of life. Here, we compared the muscle mass of malignant tumor patients who are visiting bone metastasis outpatient clinics with that of healthy subjects. Methods We compared the muscle mass of 61 malignant tumor patients with an Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 (mean 66.3 ± 12.0 years; 30 males and 31 females) attending our bone metastasis outpatient clinic since 2018 with that of 315 healthy subjects (mean 65.0 ± 17.7 years; 110 males and 205 females). Body mass index, skeletal muscle mass, and body fat percentage were assessed by bioimpedance analysis, and the skeletal muscle mass index (SMI) was calculated. Results To eliminate age bias in the malignant tumor patients and healthy subjects, 1:1 propensity score matching was performed separately for males and females. There was no significant difference in right upper limb, left upper limb, right lower limb, or left lower limb mass or SMI between the two groups, whereas trunk muscle mass and muscle mass were significantly higher in the healthy females compared with malignant tumor females. Conclusion There was no significant difference in the SMI measured by bioimpedance analysis between the two groups in either males or females, while muscle mass and trunk muscle mass were significantly lower in female malignant tumor patients than in healthy subjects. These results suggest that even malignant tumor patients whose performance status was maintained enough to allow outpatient visits still had impaired motor function.

PURPOSE: To investigate the impact of early post-injury respiratory dysfunction for neurological and ambulatory ability recovery in patients with cervical spinal cord injury (SCI) and/or fractures. METHODS: We included 1,353 elderly patients with SCI and/or fractures from 78 institutions in Japan. Patients who required early tracheostomy and ventilator management and those who developed respiratory complications were included in the respiratory dysfunction group, which was further classified into mild and severe respiratory groups based on respiratory weaning management. Patient characteristics, laboratory data, neurological impairment scale scores, complications at injury, and surgical treatment were evaluated. We performed a propensity score-matched analysis to compare neurological outcomes and mobility between groups. RESULTS: Overall, 104 patients (7.8%) had impaired respiratory function. In propensity score-matched analysis, the respiratory dysfunction group had a lower home discharge and ambulation rates (p = 0.018, p = 0.001, respectively), and higher rate of severe paralysis (p < 0.001) at discharge. At the final follow-up, the respiratory dysfunction group had a lower ambulation rate (p = 0.004) and higher rate of severe paralysis (p < 0.001). Twenty-six patients with severe disability required respiratory management for up to 6 months post-injury and died of respiratory complications. The mild and severe respiratory dysfunction groups had a high percentage of severe paraplegic cases with low ambulatory ability; there was no significant difference between them. The severe respiratory dysfunction group tended to have a poorer prognosis. CONCLUSION: Respiratory dysfunction in elderly patients with SCI and/or cervical fracture in the early post-injury period reflects the severity of the condition and may be a useful prognostic predictor.

Sarcopenia is defined as decreasing in muscle strength and mass, and dynapenia is defined as decreasing in muscle strength and maintained muscle mass. This study elucidated the prevalence and characteristics of sarcopenia and dynapenia and evaluate in elderly spinal disorders patients. 1039 spinal disorders patients aged ≥ 65 years were included. We measured age, grip strength, muscle mass, spinal sagittal alignment parameters, low back pain (LBP) scores and health-related quality of life (HR-QoL) scores. Based on the previous reports, patients were categorised into normal group: NG, pre-sarcopenia group: PG, dynapenia group: DG, and sarcopenia group: SG. Pre-sarcopenia, dynapenia, and sarcopenia were found in 101 (9.7%), 249 (19.2%), and 91 (8.8%) patients, respectively. The spinal sagittal alignment parameters, trunk muscle mass, LBP, and HR-QoL scores were significantly worse in DG and SG compared with those in PG and NG. Spinal alignment, trunk muscle mass, and clinical outcomes, including LBP and HR-QoL scores, were maintained in the PG and poor in the DG and SG. Thus, intervention for muscle strength may be a treatment option for changes of spinal sagittal alignment and low back pain.

【目的】術後急性期の重度脊髄症患者に対する免荷式歩行器とリカンベントエルゴメーターの安全性を検討した.【対象と方法】対象は2021年3月から2022年6月までに当院で手術を施行し,術直後の日本整形外科学会頸髄症治療判定基準の下肢運動機能が0.5点以下の脊髄症11例とした.調査時期は術後1日目から術後28日目までとした.調査項目は,免荷式歩行器とリカンベントエルゴメーターの有害事象と予定した計画に対する完遂の有無とした.【結果】歩行リハビリテーションは全例が免荷式歩行器およびリカンベントエルゴメーターで有害事象を認めず,かつ予定した計画を完遂できた.実施頻度は免荷式歩行器が75回,リカンベントエルゴメーターは103回とリカンベントエルゴメーターのほうが多かった.【結語】術後急性期からの免荷式歩行器とリカンベントエルゴメーターは有害事象なく安全に行えた.(著者抄録)

脊髄後索の選択的機能不全における固有感覚障害は歩行機能と日常生活活動の低下につながる.固有感覚障害を有する胸髄症の身体特性を,2020年8月から2022年10月までに手術目的で入院した胸髄症で,American Spinal Cord Injury Association motor score(lower extremity motor score)が42点以上の26例を対象として調査した.固有感覚は母趾の位置覚と母趾探し試験で評価した.母趾の位置覚障害単独は4例(15%),母趾探し障害単独は3例(12%)両方の障害は10例(38%)であった.母趾の位置覚,母趾探し障害は単独でも立位および歩行機能の低下を認め,両方の障害ではさらに低下を認めた.これらの試験の追加が,立位および歩行機能低下を引き起こす因子の特定につながるため,術後の理学療法プログラムの立案において有益があると考えられた.(著者抄録)