Hiroaki Nakashima

Study Design: Prospective multicenter cohort study. Objectives: To examine associations between improvements in arm pain, neck pain, numbness, and patient satisfaction during pharmacological treatment of cervical spine disorders. Methods: Of 256 patients with cervical spine disorders and upper extremity symptoms enrolled at 28 institutions, 220 patients (830 observations) were included. A generalized estimating equation with cluster-robust variance regressed satisfaction (5-point Likert; satisfied ≥4) on improvement in arm pain, neck pain, and numbness (NRS 0–10), adjusting for psychosocial burden (BS-POP), age, sex, and time point. An ordinal model was used as an alternative outcome specification, and sensitivity analyses were interpreted descriptively. Results: Arm pain improvement was associated with satisfaction under both binary (OR 1.095 per point, P =.022; Holm-adjusted P =.044) and ordinal (OR 1.143, P =.019) coding. Neck pain improvement was associated with satisfaction under binary coding only (OR 1.121, P =.003; Holm-adjusted P =.009; ordinal P =.447). Numbness improvement showed the same direction but was not significant in either specification (OR 1.068, P =.106; ordinal P =.377). Confidence intervals overlapped across domains, and the arm pain estimate was attenuated under inverse-probability weighting and in diagnostic subsets. Approximately one-third of observations with persistent numbness had satisfaction scores ≥4. Conclusions: Arm pain improvement was consistently associated with greater satisfaction, whereas the association with numbness improvement was less consistent. Residual numbness alone should not be considered treatment failure and should be interpreted alongside pain relief, neurological findings, and overall clinical condition. These findings support multidimensional assessment of treatment response rather than reliance on residual numbness alone in clinical practice.

Study Design: Multicenter prospective registry study. Objective: To classify patients according to whether they achieved the minimum clinically important difference (MCID) in health-related quality of life (HRQoL) after surgery for metastatic spinal tumors and to identify preoperative factors associated with clinically meaningful improvement. Summary of Background Data: As survival in patients with metastatic spinal tumors continues to improve, evaluating clinically meaningful changes in HRQoL has become increasingly important. However, factors associated with achieving clinically meaningful postoperative improvement remain unclear. Methods: Between 2018 and 2021, 413 patients undergoing surgery for metastatic spinal tumors were prospectively enrolled from 35 centers in Japan. Patients with available preoperative and 6-month postoperative EQ-5D-5L data were included in the MCID analysis (n=171). Patients were classified into the MCID improvement and non-MCID improvement groups according to the previously established MCID threshold for the EQ-5D-5L index. Patient-reported outcomes (PROs), clinical characteristics, and functional measures were compared between groups, and multivariable logistic regression analysis was performed to identify preoperative factors associated with clinically meaningful improvement. Results: Patients in the MCID improvement group demonstrated significantly greater improvements in the EQ-5D-5L index, EQ-VAS, and other PRO measures than those in the non-MCID improvement group. Compared with the non-MCID improvement group, they had poorer baseline HRQoL, poorer functional status, greater pain, and lower independence in activities of daily living. Exploratory multivariable analysis identified lower independence in dressing and greater impairment in the mobility, pain/discomfort, and anxiety/depression domains as candidate factors associated with clinically meaningful improvement. Conclusion: Patients with poorer baseline HRQoL and functional status were more likely to achieve clinically meaningful improvement after surgery for metastatic spinal tumors. These findings suggest that baseline HRQoL should be considered when interpreting postoperative outcomes and counseling patients regarding the expected benefits of surgical treatment.

Study design: Retrospective cohort study. Objectives: To correlate Hounsfield unit (HU) values, using elliptical regions of interest (ROI), that can be easily defined in routine clinical practice with magnetic resonance imaging (MRI) T2-hyperintense area fraction, as a surrogate for paraspinal muscle fat infiltration and to establish specific HU screening thresholds that may be applied with standard picture archiving and communication system (PACS). Methods: We included 136 patients (71 men; 61.0 ± 15.4 years) who underwent preoperative computed tomography (CT) and MRI within an 8-week period. Elliptical ROI HU values were measured at L2/3 and L4/5 for erector spinae, multifidus, and psoas major. MRI T2-hyperintense area fraction (Otsu thresholding) served as the fat infiltration reference. Linear mixed-effects (LME) models were used to assess the HU–T2 association and level-specific receiver operating characteristic (ROC) analyses (lower HU value side; n=136 per muscle–level) to identify thresholds for ≥30% and ≥50% infiltration criteria. Results: Intraclass coefficients = 0.709 (HU) and 0.857 (T2 fraction); Goutallier weighted kappa = 0.579. In the overall LME, β was −0.880 HU per 1% T2-fraction increase (95% confidence interval −0.935 to −0.825; marginal R² =0.502); the association was steeper in multifidus (β = −1.020) than in erector spinae (β = −0.753). Psoas major ( R = −0.226) was excluded from ROC analyses. Difference between L2/3 and L4/5 HU cutoffs was ∼20 HU. The ≥50% criterion revealed higher discrimination. Conclusions: Elliptical ROI-based HU measurements may reliably screen paraspinal muscle fat infiltration in erector spinae and multifidus using standard PACS. Specific thresholds may allow practical preoperative evaluation without additional costs or radiation.

Study Design: Retrospective cohort study. Objectives: Surgery for adult spinal deformity (ASD) is associated with postoperative mechanical complications (MCs), such as proximal junctional kyphosis (PJK). The applicability of the Global Alignment and Proportion (GAP) score for predicting MCs in older Asians remains unclear. This study aimed to evaluate the validity of the GAP score in Asians patients by stratifying them into younger and older groups. Methods: We studied 274 patients who had undergone multi-level spinal fusion and were followed up for at least 2 years. Patients were divided into a younger group (Under-69, n = 122) and an older group (Over-70, n = 152). MCs were assessed at 2 years postoperatively. Propensity score matching was performed to compare the incidence of MCs across groups. Logistic regression models were used to examine the interaction between GAP score and age. Results: MC occurred in 93 patients (34%), with no significant differences between groups. In the Under-69 group, GAP scores did not correlate with MC occurrence. In contrast, the in the Over-70 group patients with MCs had significantly lower GAP scores (6.6 ± 3.4 vs. 8.0 ± 3.2, P = 0.022). The interaction between GAP score and age was not significant in the logistic regression models. Conclusions: The GAP score demonstrated limited predictive ability for MCs in this Asian ASD cohort, particularly in older patients. These findings suggest that alignment-based prediction models alone may be insufficient for MC risk stratification in aging populations.

Was not provided for this article.

Was not provided for this article.

A retrospective multicenter study. To determine whether the extent of intramedullary hyperintensity on initi... Asian Spine Journal 2026;():-.

Purpose This study aimed to evaluate postoperative outcomes, including clinical results, radiological assessments, and complications, in patients over 50 years old with nondisplaced femoral neck fractures (Garden classification I–II) treated with cannulated cancellous screw (CCS) fixation with or without a side-plate. Methods This multicenter retrospective study analyzed 620 patients aged ≥ 50 years with nondisplaced femoral neck fractures who underwent osteosynthesis between 2018 and 2020 across 12 affiliated hospitals. After propensity score matching, 41 patients were included in each group. All patients were followed for at least one year postoperatively. Patients were categorized into a CCS group (Group C) and a CCS with side-plate group (Group P). Walking ability, radiological evaluations, operative time, and complications were assessed. Results At six months postoperatively, femoral neck shortening did not differ significantly between Group C and Group P (C: 4.20 ± 5.37 vs P: 3.63 ± 3.29 mm, p = 0.701). At one year postoperatively, femoral neck shortening was significantly greater in Group C than in Group P (C: 5.58 ± 4.38 vs P: 2.99 ± 3.64 mm, p = 0.009). Walking ability at final follow-up did not differ between groups (p = 0.142). Operative time was longer in Group P (C: 33.85 ± 15.56 vs P: 56.37 ± 21.63 min, p < 0.001). Postoperative complications were comparable between groups. Conclusions Plate augmentation reduced femoral neck shortening but increased operative time, without significant differences in complications or walking ability. CCS fixation without a side-plate may be sufficient for selected patients with nondisplaced femoral neck fractures.

Introduction: The addition of corticosteroids to selective nerve root block (SNRB) is widely practiced for lumbar radiculopathy, yet robust evidence regarding its efficacy for functional outcomes remains limited. We evaluated whether adding corticosteroids to local anesthetic in SNRB relieves functional disability and improves quality of life in patients with lumbar radiculopathy.Methods: This multicenter, prospective cohort study enrolled 78 patients with single-level lumbar radiculopathy. Patients received fluoroscopy-guided SNRB with either corticosteroids (dexamethasone, betamethasone) plus 1% lidocaine (n=64) or lidocaine alone (n=14). The primary outcome was the Oswestry Disability Index (ODI) at 90 and 180 days. Secondary outcomes included visual analog scale (VAS) scores for leg pain, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), and minimal clinically important difference (MCID) achievement rates. Linear mixed-effects models were used for analysis.Results: The steroid group indicated significantly greater ODI improvement at 90 days (27.9 vs 47.1; mean difference, 19.2 points [95% confidence interval (CI), 6.8-31.6]; p=0.002) and 180 days (29.0 vs 44.1; mean difference, 15.1 points [95% CI, 2.3-27.9]; p=0.022), with large effect sizes (Cohen d>0.8). Significant improvements favoring corticosteroids were observed for VAS scores at 90 days (3.5 vs 5.7; p=0.018) and 180 days (3.7 vs 5.9; p=0.023) and multiple JOABPEQ domains. MCID achievement was significantly higher in the steroid group at 90 days (75.0% vs 33.3%; p=0.043); the number needed to treat was 2.4. Adverse event rates were similar in the groups, and no serious adverse events occurred. Benefits plateaued between 90 and 180 days.Conclusions: Adding non-particulate corticosteroids to SNRB significantly relieved functional disability and pain and improved quality of life in patients with lumbar radiculopathy, with the most pronounced group differences occurring at 90 days and sustained through 180 days. Clinically, the 90-day timepoint is optimal for evaluating treatment success and determining the need for alternative treatments.