Masashi Uehara

Study Design.: Retrospective two-center surgical cohort with cross-sectional preoperative comparisons and longitudinal postoperative follow-up. Objective.: To characterize domain-specific associations between age at surgery and preoperative and postoperative Scoliosis Research Society-22 revised (SRS-22r) scores while testing robustness to adult heterogeneity and incomplete follow-up. Summary of Background Data.: Age may relate differently to individual SRS-22r domains, but comparisons of patients operated at different ages cannot establish the effect of earlier surgery. Methods.: The cohort comprised 438 unique patients aged 10–79 years with documented adolescent-onset idiopathic scoliosis; de novo degenerative scoliosis was excluded. Age was modeled continuously, with natural cubic splines and completed-year bands used secondarily. Two- and 5-year analyses included only patients calendar-eligible at the September 28, 2026 data lock. Baseline-adjusted scores, domain-by-age interactions, and inverse-probability-of-follow-up weighting were analyzed. Results.: Paired function was available for 93.8% and 85.6% of eligible patients with baseline scores at 2 and 5 years. Older age was not associated with smaller observed functional change. Each 10-year older age was associated with lower baseline-adjusted postoperative function at 2 years (β, −0.196; 95% CI, −0.276 to −0.116) and 5 years (β, −0.160; 95% CI, −0.241 to −0.079; both qP <0.001). Conclusion.: In this predominantly adolescent surgical cohort with a small, selected adult subgroup, older age was associated with lower postoperative function after adjustment for baseline function and measured covariates. These observational findings do not show that operating earlier would improve the outcome of the same patient and should complement, not replace, radiographic and patient-specific decision-making. Level of evidence.: 3

Cervical pedicle screw (CPS) fixation is a well-established technique for achieving rigid posterior stabilization of the cervical spine. Since its introduction, the indications for CPS have expande...

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

Recognition of a dominant vertebral artery (VA) is important in cervical spine surgery planning. However, few reports have discussed the relationship between the VA and the transverse foramen (TF). This study investigated the morphological features of the VA and TF, and examined for any associated risk factors for VA injury. We retrospectively reviewed 90 patients who underwent cervical contrast-enhanced computed tomography angiography (CTA). We evaluated VA diameter, TF dimensions, TF area, and the occupation ratio of the VA within the TF from C1 and C3-6 levels. TF mediolateral diameter, TF anteroposterior diameter, TF area, and VA occupation ratio were all larger in the VA dominant group. The shape of the TF was elongated vertically at C1 and horizontally at C3, with the degree of horizontal elongation decreasing from C4 to C6. The inter-TF distance was wide at C1 and narrow at C3. The mediolateral diameter, anteroposterior diameter, and area of the C5 TF tended to be larger on the dominant VA side. In patients with a left-right discrepancy in the TF on CTA, there is a tendency for a dominant VA to be associated with the larger TF.

Several risk factors have been associated with sagittal progression of ossification of the posterior longitudinal ligament (OPLL), yet there remains no consensus regarding its postoperative behavior. This study investigated the longitudinal changes in OPLL following posterior cervical surgery and aimed to identify factors related to postoperative sagittal progression. Twenty-six patients (23 men and 3 women; mean age 62.0 ± 13.1 years) who underwent posterior cervical spine surgery for OPLL and at least 1 year of computed tomography follow-up were retrospectively reviewed. Changes in the ossification index (OP-index), defined as the sum of ossified vertebral and intervertebral levels, were evaluated using serial computed tomography scans. Postoperative sagittal OPLL progression was defined as an OP-index increase ≥1 point over the preoperative OP-index score. Univariate and multivariate logistic regression analyses were conducted to identify associated factors. Postoperative sagittal OPLL progression was observed in 13 of 26 patients (50%). Progression tended to be more frequent in fusion cases than in nonfusion cases (58.8% vs 33.3%, P = 0.41). Multivariate analysis revealed segmental-type OPLL as an independent risk factor for postoperative sagittal progression (OR 17.6, 95% CI 1.14-272). Mean follow-up duration was 35.3 ± 24.8 months. Among the patients who showed postoperative sagittal OPLL progression, the mean time to progression was 26.0 ± 19.0 months. No significant associations were found between OPLL advancement and age, sex, body mass index, nutritional status, number of fused levels, or duration of follow-up. Sagittal OPLL progressed inside the fused segment in 90% of fusion cases. Postoperative sagittal OPLL progression can occur regardless of fusion surgery, with a potentially higher risk in patients with the segmental type. Long-term postoperative studies are needed to clarify ossification dynamics in OPLL patients. Postoperative sagittal progression of cervical OPLL may occur regardless of posterior fusion surgery, particularly in patients with segmental-type OPLL.

Purpose: Neurofibromatosis type 1 (NF-1) has been associated with scoliosis, cervical deformity, and other spinal deformities. In progressive cases of NF-1-associated cervical deformity, surgical intervention may be required to prevent further deterioration. However, there remain no generally recognized guidelines on the surgical strategy for NF-1-related cervical deformity. Case presentation: A 39-year-old man with diagnosed NF-1 was airlifted to our hospital due to neck pain and bilateral upper extremity paralysis. X-rays and computed tomography (CT) revealed severe neck deformity, including anterior displacement of the C5 vertebral body. We performed laminectomy (C4-C6), posterior fixation (C2-T2), and autologous bone grafting using a pedicle screw construct with cobalt-chromium rods in addition to accessory rods for reinforcement. No surgery-related adverse events were recorded. Successful bone fusion was confirmed by X-rays and CT 2 years postoperatively, with no noticeable correction loss. Conclusion: In the reported case of severe cervical deformity attributed to NF-1, posterior spinal fusion using a multi-rod construct achieved favorable outcomes and may be considered a viable treatment option.

Dermatan sulfate (DS) is a glycosaminoglycan known to contribute to tissue strength through collagen fibril assembly. Musculocontractural Ehlers–Danlos syndrome (mcEDS) caused by pathogenic variants in the gene that encodes carbohydrate sulfotransferase 14 (CHST14) (mcEDS-CHST14) is a representative disorder of DS deficiency. Skeletal lesions, such as progressive spinal deformity and osteoporosis/osteopenia, are significant manifestations of mcEDS-CHST14, which can lead to deterioration in quality of life. To characterize skeletal alterations associated with DS deficiency, we performed comprehensive analyses of the skeletal phenotypes in Chst14 gene-deleted (Chst14−/−) mice. Chst14−/− mice exhibited progressive kyphosis, proximal femoral deformities, and decreased bone strength, as well as reduced trabecular bone mass and structural parameters, from a young age. Qualitative ultrastructural alterations of collagen fibrils in cortical bone were observed in middle-aged Chst14−/− mice by transmission electron microscopy. In addition, cortical bone showed increased expression of receptor activator of NF-κB (Rank), a gene involved in osteoclast differentiation, in middle age. Histomorphometric analyses of cancellous bone demonstrated reduced trabecular structural parameters in Chst14−/− mice, including decreases in bone volume and trabecular number. These findings indicate age-dependent alterations in both cortical and cancellous bone compartments that may contribute to progressive skeletal deformation. The present study provides insight into skeletal alterations associated with mcEDS-CHST14 and highlights a broader role of DS in maintaining bone structure and strength.

Study design Multicenter retrospective cohort study. Objectives To investigate the impact of delayed diagnosis on treatment decisions and neurological outcomes in elderly patients with cervical spinal cord injury (CSCI) without radiographic evidence of trauma (SCIWORET). Setting Nationwide multicenter registry of the Japan Association of Spine Surgeons with Ambition (JASA). Methods Data from patients aged ≥65 years with traumatic cervical SCIWORET treated between 2010 and 2020 were reviewed. Delayed diagnosis was defined as a diagnosis of CSCI made more than 24 hours after injury, either because of (1) physician delay (missed diagnosis despite presentation) or (2) patient delay (injury-to-hospital arrival > 24 hours). Clinical characteristics, radiological findings, treatment strategies, and neurological outcomes (American Spinal Injury Association Impairment Scale, AIS) were compared between early and delayed diagnosis groups. Results Among 613 elderly patients with SCIWORET, 81 (12.8%) experienced delayed diagnosis. These patients were significantly older (p = 0.048), more frequently dependent for ambulation (p < 0.001), and commonly injured by ground-level falls (p < 0.01). Initial AIS grades and radiological findings were comparable between groups. However, patients with delayed diagnosis underwent more frequent surgical intervention at admission (p < 0.001) and more frequent conversion from conservative to surgical management due to neurological deterioration (p < 0.001). Final AIS grades did not differ significantly between groups. Conclusions Delayed diagnosis of SCIWORET in elderly patients is associated with increased surgical intervention without improved neurological recovery. Early recognition and timely MRI assessment may help reduce potentially avoidable surgery.

Purpose Investigate whether Cobb angle can be predicted by angle of trunk rotation (ATR) measurements with a scoliometer and identify the characteristics of hard-to-predict cases. Methods We retrospectively analyzed 176 patients who were examined for AIS at our department between 2011 and 2021. The cohort included 160 girls and 16 boys aged 11 years (83 patients) or 12 years (93 patients). ATR was determined with an OSI-Scoliometer (Orthopedic Systems, Inc., Union City, CA, USA). Risser grade, Cobb angle, coronal balance, and clavicular angle were all measured using standing full-length frontal radiographs. Coronal balance was measured as the distance of the C7 plumb line (C7PL) to the central sacral vertebral line. We defined the underestimated group as having a predicted Cobb angle > 1 standard deviation (SD) lower than the actual Cobb angle. Results ATR and Cobb angle were strongly and positively correlated in the cohort (r = 0.883, P < 0.001). To investigate ATR values for use in treatment decision-making, the determined cut-off value of ATR for > 25° Cobb angle was 7.5° (area under the receiver operating characteristic curve [AUROC]: 0.895, sensitivity: 0.810, specificity: 0.838) and for > 45° Cobb angle was 10.5° (AUROC: 0.941, sensitivity: 1.000, specificity: 0.781). We observed 23 patients in the underestimation group. Actual Cobb angle was significantly higher in the underestimation group, which also included significantly more patients with larger C7PL deviation and with right shoulder up. Logistic regression analysis revealed that the larger the Cobb angle at the time of ATR measurement, the higher the risk of underestimating the Cobb angle in our prediction formula. Specifically, the odds ratio suggests that a 10° increase in the Cobb angle results in a 2.3-fold increase in this risk. Conclusion ATR and Cobb angle were strongly correlated, with ATR cut-off values of 7.5° and 10.5° to predict Cobb angle > 25° and > 45°, respectively. Although the accurate prediction of Cobb angle appears difficult, especially for larger curves, this method may be useful in determining the need for bracing or surgical treatment without radiography.