Introduction: Endoscopic spine surgery (ESS) presents advantages over traditional microscopic techniques but faces limitations in terms of field of view and depth perception. Virtual reality (VR) devices offer solutions by integrating real-time digital images into the surgical field, enabling magnification and teleproctoring.

Methods: The study was conducted in two phases. In the first phase, 55 surgeons completed a pre-use questionnaire. In the second phase, 19 surgeons participated in cadaveric practical training using the device and completed a post-use survey. Data were analyzed using R software.

Results: Following device use, surgeon confidence in magnification increased significantly (from 21% to 57%), with improved perception of image quality. Acceptance of teleproctoring rose from 33% to 94.7%. The device was considered superior to the operating microscope in both image quality and ergonomics.

Conclusions: VR head-mounted devices enhance visualization in ESS, allow intraoperative access to imaging, and support remote guidance via teleproctoring. Their adoption may contribute to improved training, planning, and surgeon ergonomics. However, additional controlled studies are required to determine their effects on clinical outcomes and operative performance.

Introduction: Anterior cervical discectomy and fusion (ACDF) is a common procedure for cervical degenerative disc disease, with a growing shift toward outpatient surgery. Despite advancements enabling shorter hospital stays, same-day discharge remains a complex decision influenced by factors such as case timing and surgeon-specific practices. This study aims to identify patient and operational factors associated with same-day discharge following ACDF.

Methods: We retrospectively analyzed all elective ACDF procedures performed by 24 different surgeons across 3 affiliated hospitals within a large urban health system between January 2021 and December 2022. Patient and clinical factors, case timing, and surgeon-specific practices were compared between patients who received same-day discharge and those who were admitted on the same day following ACDF.

Results: Among the 530 elective ACDF procedures analyzed, 18.5% resulted in same-day discharge. Same-day discharge occurred significantly more frequently in procedures involving fewer operative levels, no surgical drain, and lower estimated blood loss (EBL). In contrast, factors such as age, Charlson Comorbidity Index, American Society of Anesthesiologists score, and preoperative antiplatelet or anticoagulation use did not significantly impact discharge rates. Earlier case completion times were strongly associated with same-day discharge, with 69.4% of such discharges occurring in cases completed before 14:00. Surgeon preference emerged as a key determinant, with the 15 surgeons who performed 10 or more procedures falling into 3 distinct categories: those who never, rarely, or routinely discharged patients on the same day.

Conclusions: Surgeon preference plays a critical role in shaping discharge decisions following ACDF. Alongside case complexity, EBL, drain usage, and timing, surgeon preference strongly influences whether a patient is discharged on the same day. Identifying and understanding the concerns underlying variable surgeon practice patterns will help promote standardization of discharge criteria, optimize selection for same-day discharge, and improve healthcare resource utilization.

Introduction: The Japanese Scoliosis Society conducted a survey on the complications of pediatric spinal deformity surgeries in 2012, 2014, and 2017. However, a registry-based survey was necessary to systematically and comprehensively identify complications, and a web-based registry system was established. This study aimed to investigate the frequency of pediatric spinal deformity surgeries and perioperative complications in Japan in 2022, using a web-based registry.

Methods: Of the 158,263 cases collected from 1,032 institutions, 1,945 (485 boys and 1,460 girls) were included in the study. The diagnoses were idiopathic scoliosis (64.9%), congenital scoliosis (10.1%), neuromuscular scoliosis (7.4%), congenital kyphoscoliosis (1.1%), and others (16.5%). The intraoperative, postoperative (within 30 days), and systemic (within 30 days postoperatively) complications were investigated.

Results: The overall complication rate was 6.0% (intraoperative, 2.5%; postoperative, 2.4%; and systemic, 2.0%). The complication rates by diagnosis were highest in congenital kyphosis (25.0%), followed by congenital kyphoscoliosis (18.2%) and neuromuscular scoliosis (13.3%), whereas idiopathic scoliosis (10-18 years old) had a complication rate of 3.7%. The most common intraoperative complications were massive bleeding (>2,000 mL) in 0.9%, dural tears in 0.7%, and nerve injury in 0.2% of the patients. The most frequent postoperative complications were neurologic deficits (0.8%), surgical site infections (0.8%), and implant failure (0.5%). The most frequent postoperative systemic complications were respiratory (0.6%) and urinary (0.4%).

Conclusions: This nationwide web-based registry study provides a highly comprehensive report on pediatric scoliosis surgery in Japan in 2022. The complication rates were notably high for congenital kyphosis, congenital kyphoscoliosis, and neuromuscular scoliosis. These findings may help improve patient and family understanding of the risks associated with various spinal deformities and support shared decision-making in pediatric surgical care.

Introduction: Ultrasound-guided cervical nerve root block (US-CNRB) is increasingly recognized as a safer alternative to fluoroscopy-guided procedures for treating cervical radiculopathy, owing to its ability to visualize neural and vascular structures in real time and to avoid exposure to radiation and contrast media. However, its clinical adoption remains limited due to concerns regarding inadvertent vascular puncture and misidentification of cervical levels. This study focuses on anatomical anomalies at the C6 and C7 levels, which are critical to the accuracy and safety of US-CNRB, and investigates the prevalence of morphological variations using cervical computed tomography (CT).

Methods: This retrospective observational study included patients who underwent cervical CT between April 2018 and March 2020. Patients with tumors, rheumatoid arthritis, infectious spondylitis, destructive spondyloarthropathy, or a history of cervical spine surgery were excluded. Axial and sagittal CT images were analyzed to assess two specific anatomical variants: absence of the anterior tubercle at C6 and presence of the anterior tubercle at C7. Two board-certified orthopedic spine surgeons independently assessed the images. Descriptive statistics and Cohen's kappa coefficient were used for analysis, with a p<0.05 considered statistically significant.

Results: We included 671 patients (359 females, 312 males; mean age: 62.1 years). Anatomical variants were observed in 1.34% (9/671) of cases: absence of the anterior tubercle at the C6 vertebra in 0.45% and presence of the anterior tubercle at C7 in 0.89%. No patient had both anomalies. Interobserver agreement was high, with disagreement in only one case. The Cohen's kappa coefficient for interobserver reliability was 0.97.

Conclusions: Although rare, anatomical anomalies at C6 and C7 can obscure critical landmarks during US-CNRB, increasing the risk of level misidentification and procedural errors. Recognizing these variants through preprocedural imaging is essential to improve the safety and precision of cervical spine interventions.

Introduction: Surgical decompression is necessary for anterior paradiscal-type thoracic spine tuberculosis with a neurological deficit; nevertheless, if pedicle screw fixation is unsuccessful, laminectomy may result in pan-vertebral instability. No available studies compare traditional anterolateral decompression (ALD) with the convenient, less extensive technique of transpedicular decompression (TPD).

Methods: This randomized comparative study of 20 cases of thoracic spine tuberculosis (T2-T12) used a posterior midline surgical approach with pedicle screw instrumentation. Diseased pedicle removal by eggshell technique (TPD) was compared with decompression by removal of the posterior part of the rib, transverse process, pedicle, and posterolateral part of the diseased vertebral body (ALD).

Results: Both groups had similar lengths of skin incision, intraoperative blood loss, and blood transfusion, but the duration of surgery was significantly less (p-value 0.019) in the TPD (156.5 minutes) than in the ALD group (184.5 minutes). Additional hemi-laminotomy was needed in two cases of TP, in the absence of liquid pus. Both groups showed similar neurological recovery except for one case of multidrug resistance in the ALD group. Improvements in the modified Japanese Orthopedics Association score (p=0.719); visual analog scale (p=0.259) and Nurick scale (p=0.387) had no statistical difference between the two groups. Mean kyphosis correction of 6.64⁰ and 6.45⁰ and mean loss of correction at 2-years were 4.74⁰ and 1.98⁰ in the TPD and ALD groups, respectively. Complications included one case of surgical site infection in each group.

Conclusions: Similar outcomes of both approaches. TPD is quicker but may need hemi-laminotomy in the absence of liquid pus. ALD enables thick organized pus removal without compromising lamina in paradiscal-tuberculosis.

Introduction: To evaluate the differences in anterior spinal bridging and sagittal spinal parameters between patients with diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) using whole-spine computed tomography (CT).

Methods: This retrospective study included patients with DISH (n=111) and AS (n=27). The number of anterior spinal bridges and sagittal spinal parameters was evaluated. The sagittal vertical axis (SVA) evaluated by whole-spine CT was defined as sup-SVA. Patients were further evaluated by matching their age and sex.

Results: Anterior spinal bridging frequently occurred in the thoracic spine in DISH and AS. In AS, bridging occurred in the lumbar spine according to the number of anterior spinal bridges. Sup-SVA and T5-T12 thoracic kyphosis (TK) were significantly greater in AS, and lumbar lordosis (LL) was significantly smaller in AS. TK was greater according to the number of anterior spinal bridges in both DISH and AS. Sup-SVA in DISH was greater according to the number of anterior spinal bridges, especially in the thoracic spine, whereas it was greater according to the lumbar in AS. LL in AS was smaller according to the number of lumbar bridges. Sup-SVA in DISH correlated with TK, whereas it correlated with both TK and LL in AS.

Conclusions: In patients with AS, the spine tends to bridge from the lumbar to the thoracic spine, causing kyphosis in the thoracolumbar spine. In patients with DISH, the spine tends to bridge from the thoracic spine, causing kyphosis in the thoracic spine. Thus, sup-SVA is greater in AS than in DISH.

Introduction: Low back pain (LBP) is a leading cause of disability worldwide, particularly in aging populations. While the Oswestry Disability Index (ODI) is widely used to assess LBP-related disability, few studies have evaluated its long-term trajectory and predictive factors in general populations.

Methods: This 7-year longitudinal study included 553 community-dwelling adults (mean age 66.3 years) from the Wakayama Spine Study, a population-based sub-cohort of the Research on Osteoarthritis/Osteoporosis against Disability (ROAD) study. Participants completed whole-spine magnetic resonance imaging and responded to the ODI questionnaire at baseline and follow-up. Disability levels were classified as mild (0%-20%), moderate (21%-40%), or severe (41%-60%). Longitudinal transitions in disability categories were analyzed descriptively. Multiple linear regression was used to identify predictors of ODI deterioration.

Results: The mean ODI score significantly increased from 9.6±11.5 at baseline to 12.2±14.2 after 7 years (p<0.001), although the change did not reach clinical significance. Among participants initially classified as mildly disabled (n=468), 88.0% remained stable, while 12.0% worsened. Of those with moderate disability (n=73), 35.6% improved, 44.0% remained unchanged, and 20.5% worsened. No participant with severe disability (n=40) improved to mild. Female sex, older age, higher body mass index, and vertebral fractures (semiquantitative grade ≥2) were significant predictors of worsening disability (p<0.05). Higher baseline ODI was inversely associated with deterioration.

Conclusions: In this population-based cohort, LBP-related disability modestly worsened over 7 years. Older adults, women, individuals with obesity, and those with vertebral fractures were at greatest risk. These findings support early intervention and screening strategies to prevent disability progression in at-risk populations.

Introduction: This study aimed to identify the factors associated with the postoperative deterioration of sagittal balance after surgery for adult spinal deformity (ASD), focusing on preoperative alignment and pelvic incidence (PI).

Methods: We retrospectively reviewed the medical records of 87 patients who underwent corrective surgery for ASD (2017-2020). Sagittal balance was assessed using the sagittal balance classification (SBC). The patients were classified as balanced (maintained SBC grade 1 or 2) or imbalanced (deteriorated to grade 3). Radiographic parameters, clinical outcomes (Japanese Orthopedics Association scores and mechanical complications), and bone mineral density were analyzed.

Results: In 15 patients (17.2%), the sagittal balance deteriorated to grade 3 (imbalanced group). Factors significantly associated with postoperative deterioration of sagittal balance included preoperative grade 3 SBC (73.3% vs. 23.6%, p<0.001), steroid use (26.7% vs. 2.8%, p<0.01), pelvic fusion (80% vs. 51.4%, p=0.049), higher preoperative PI, sacral slope, and sagittal vertical axis. At 2 years, the imbalanced group showed a significantly greater corrective loss of the lumbar spine. Receiver operating curve analysis identified preoperative PI ≥52.1° as predictive of postoperative imbalance (sensitivity 86.7%, specificity 66.7%). The clinical outcomes were similar, but the reoperation rates were higher in the imbalanced group (20.0% vs. 2.8%, p=0.03).

Conclusions: High preoperative PI, severe sagittal imbalance, steroid use, and pelvic fusion were predictive of postoperative sagittal balance deterioration, underscoring the need for personalized preoperative planning.

Introduction: High rates of postoperative rod fracture at the lumbosacral junction have been reported after long spinopelvic fixation. In the prevention of rod fractures, supplemental accessory rods (ARs) and lateral interbody fusion are commonly used and reportedly effective. However, the optimal AR placement to mitigate rod stress at the lumbosacral junction is unclear. We therefore used a synthetic bone model and a finite element model concurrently to address their respective shortcomings.

Methods: Both models included the lumbar spine (L1-L5) and the pelvis, and were instrumented with a screw and rod system and lateral interbody fusion cages to closely resemble actual surgical procedures. The four different constructs were: two primary rods (PRs) without ARs, PRs+contoured long ARs, PRs+short ARs, and PRs+straight long ARs. In our synthetic model, we applied vertical load to the constructs and measured rod strain at L5-S1 using strain gauges. We calculated a mean value of the five rods in each construct. In our finite element model, we measured maximum principal stresses at L5-S1 after the application of flexion/extension, lateral bending, and axial rotation loads.

Results: In our synthetic bone model, there was significant reduction of rod strain by 52% in PRs+straight long ARs compared with PRs without ARs (p=0.023). A reduction of average principal stress in the finite element model was observed in PRs+straight long ARs by up to 44.2% (highest against flexion load) compared with PRs without ARs.

Conclusions: We conducted concurrent biomechanical analyses using a synthetic bone model and a finite element model. We recommend straight long ARs to prevent rod fracture at the lumbosacral junction in long spinopelvic fixation.

Introduction: Brace treatment is an essential nonoperative strategy to prevent curve progression in adolescent idiopathic scoliosis (AIS), yet it can cause substantial psychological stress. However, few studies have investigated factors associated with brace-related psychological stress. This study aimed to evaluate the association between pre-bracing health-related quality of life (HRQOL) and brace-related psychological stress during treatment.

Methods: This study retrospectively analyzed female patients with AIS aged 10-15 years who initiated brace treatment at a single center. Inclusion criteria were a baseline Cobb angle of 20-40°, initiation of full-time bracing, and completion of standardized questionnaires. Baseline assessments included demographic and radiographic data, as well as patient-reported outcomes: the Scoliosis Research Society-22r and the Scoliosis Japanese Questionnaire-27 (SJ-27). Brace-related psychological stress was assessed at multiple time points during the first year using the Japanese version of the Bad Sobernheim Stress Questionnaire-Brace (JBSSQ-brace). A linear mixed-effects model was used to identify baseline factors associated with higher stress levels over time.

Results: A total of 151 patients (mean age 12.4±1.1 years) were included. At one month, 32.5% of patients reported moderate to severe stress (JBSSQ-brace ≤16), and 11.8% of the total cohort experienced worsening stress during the first six months. In multivariable analysis, a higher baseline SJ-27 score was significantly associated with increased brace-related psychological stress over time (β=−0.15±0.04, p<0.001). Other factors, including age, skeletal maturity, pre-bracing Cobb angle, and in-brace correction rate, were not significant.

Conclusions: Lower pre-bracing HRQOL, as measured by the SJ-27, was independently associated with increased psychological stress during brace treatment. Early psychological screening using AIS-specific HRQOL tools may help identify high-risk patients and provide timely support to improve compliance and treatment outcomes.

Introduction: Some adult patients with spinal deformities show a sloping spine, not kyphosis, with severe global malalignment and deterioration of patient-reported outcome measures (PROMs). The purpose of this study was to elucidate sloping-type deformities on the basis of radiographic parameters and PROMs.

Methods: This study included participants from a health screening program with sagittal vertical axis (SVA) >40 mm. The sloping-type deformity (S group) was defined as the deformity in which all posterior vertebral walls were positioned anteriorly to the vertical line extending from the posterior end of the sacrum on standing whole-spine lateral radiographs. SVA, thoracic kyphosis (TK), lumbar lordosis (LL), L4-S angle, pelvic incidence (PI), and pelvic tilt (PT) were measured. PROMs were evaluated using the Oswestry Disability Index (ODI).

Results: A total of 348 participants (142 men and 206 women; average age 75.8 years) were included in the study, and 50 participants (14.4%) were classified into the S group. The mean age and measured variables of the S and non-sloping-type (non-S) group were 76.1, 72.6 years; SVA 111, 79 mm; TK 24, 35°; L4-S 15, 30°; PI 58, 49°; PT 27, 21°; PI-LL 28, 14°; and ODI 22, 15%, respectively. There were 30 participants (60%) with evident lumbar anterolisthesis in the S group and 76 (25.5%) in the non-S group (p<0.001). The S group had larger SVA, PI, PT, and PI-LL (all p<0.001) and lower TK and L4-S angle (both p<0.001) than did the non-S group. The S group showed an inferior ODI to that of the non-S group (p=0.012).

Conclusions: The sloping-type deformity showed a significantly higher PI, and worse spinopelvic alignment and PROMs. The significant factors contributing to the incidence of sloping-type deformities were higher PI, prevalence of lumbar anteriolisthesis, and lower TK and L4-S angle.

Introduction: The application of intraoperative computed tomography (CT) navigation in anterior cervical spine surgery remains limited because of challenges in securing a stable reference frame during supine positioning and the absence of reliable bony landmarks in the anterior cervical region. To overcome these limitations, we propose a novel technique involving reference frame placement on the proximal diaphysis of the clavicle and evaluate its feasibility and navigation accuracy.

Technical Note: Five patients (4 males, 1 female; mean age 59±15 years) underwent anterior cervical surgery for cervical ossification of the posterior longitudinal ligament (n=2), cervical disc herniation (n=2), and cervical spondylotic amyotrophy (n=1).

The reference frame was affixed to the clavicle contralateral to the operating surgeon. Intraoperative CT scans were obtained using a robotic C-arm angiography system and navigation was performed via an optical surgical navigation system. Navigation accuracy was assessed in 3 planes: mediolateral (x), craniocaudal (y), and anteroposterior (z). Navigation errors (mean±standard deviation) were 0.29±0.24 mm (x), 0.47±0.31 mm (y), and 0.64±0.59 mm (z), all within clinically acceptable limits. No intraoperative or postoperative complications, including clavicle fracture, subclavian vessel injury, or supraclavicular nerve damage, were observed. Compared with previously reported techniques, this method demonstrated favorable accuracy.

Conclusions: Clavicle-based reference frame placement offers high navigation accuracy and technical feasibility in anterior cervical spine surgery. Larger studies are warranted to confirm its clinical utility and safety.