木村 敦

STUDY DESIGN: A multicenter prospective cohort study. OBJECTIVE: To evaluate the clinical significance of intramedullary signal intensity (SI) changes on T2-weighted magnetic resonance imaging (MRI) in patients with cervical ossification of the posterior longitudinal ligament (OPLL) and assess their impact on surgical outcomes. SUMMARY OF BACKGROUND DATA: In OPLL, SI changes on MRI are frequently observed, but their prognostic significance remains unclear. Although some studies associate SI changes with poor neurological function and recovery, others report a weak correlation. METHODS: A total of 402 patients with cervical OPLL were analyzed. Patients were classified into SI (+) and SI (-) groups based on preoperative T2-weighted MRI. Clinical outcomes, including the Japanese Orthopaedic Association (JOA) score, the visual analog scale, and the JOA Cervical Myelopathy Evaluation Questionnaire, were evaluated preoperatively and at two years postoperatively. Multiple regression and logistic regression were performed to adjust for confounders. RESULTS: A total of 348 cases (86.6%) were in the SI (+) group. Patients in the SI (+) group were older and had greater cervical range of motion (ROM). They exhibited lower preoperative JOA scores and more severe extremity pain. However, at two-year follow-up, neurological improvement, pain reduction, and patient-reported outcomes did not differ significantly between groups. CONCLUSION: SI changes on MRI are associated with worse preoperative neurological function and greater pain but do not predict inferior surgical outcomes. Surgical decompression remains effective regardless of SI changes, which can be valuable information for explaining the prognosis to patients in clinical practice.

STUDY DESIGN: A multicenter prospective cohort study. OBJECTIVE: To comprehensively evaluate the surgical impact, including patient-reported outcomes (PROs), in elderly patients with cervical ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: With the rise of aging populations worldwide, understanding the impact of age on treatment outcomes for cervical OPLL has become increasingly important. Previous studies on degenerative cervical myelopathy have highlighted inconsistent outcomes for elderly patients, with limited focus on OPLL and PROs. METHODS: This prospective, multi-institutional study included 402 cervical OPLL patients from 2014 to 2017, categorized into elderly (≥75 y, n=79) and non-elderly (<75 y, n=323) groups. Clinical outcomes were assessed preoperatively and two years postoperatively using cervical Japanese Orthopedic Association (JOA) scores, visual analog scale (VAS) scores, and the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). Multivariable regression analyses were conducted, adjusting for potential confounders, including demographic variables and imaging characteristics. RESULTS: Elderly patients had worse preoperative JOA scores (9.6 vs. 11.1, P<0.01) and lower postoperative scores at two years (12.3 vs. 14.0, P<0.01). However, the improvement in JOA scores was comparable (2.7 vs. 3.0, P=0.48), with both exceeding the minimum clinically important difference (MCID). Complication rates and VAS score improvements were also comparable. JOACMEQ outcomes demonstrated significantly poorer upper extremity function in the elderly group following surgery (P=0.02), whereas no significant differences were observed between the two groups in other functional domains. CONCLUSION: Despite worse baseline neurological function, elderly OPLL patients achieved similar degrees of postoperative neurological improvement as non-elderly patients. However, upper extremity function is unlikely to show significant improvement following surgery in elderly patients.

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 assessments with clinical outcomes. Background. Despite its proven usefulness in degenerative spinal diseases and deformities, the MCID remains unexplored regarding surgery for spinal metastases. Patients and 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, 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-Visual Analog Scale, 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. Level of Evidence. II.