Introduction: Successful spinal fusion depends on achieving reliable arthrodesis, and bone graft selection is a critical determinant of outcomes. Although autologous iliac crest bone graft remains the biological gold standard, limitations such as donor-site morbidity and insufficient volume have prompted the use of alternatives, including allograft, demineralized bone matrix (DBM), hydroxyapatite, and β-tricalcium phosphate. The introduction of biologics-such as recombinant human bone morphogenetic protein-2 (rhBMP-2) and cell- or peptide-based constructs-has further expanded grafting options internationally. However, in Japan, the clinical use of biologics remains unapproved, and allograft availability is restricted, necessitating reliance on autograft, DBM, and ceramic substitutes.

Methods: A narrative review of recent clinical and experimental studies was conducted, emphasizing graft performance across cervical, lumbar, anterior/lateral, multilevel, and minimally invasive procedures. Practical considerations, including cost, storage, supply stability, and regional regulatory constraints, were integrated into the analysis.

Results: Graft performance varied substantially according to surgical context. DBM and ceramic grafts often achieved satisfactory outcomes in cervical fusion, whereas lumbar fusion required mechanically robust extenders. Multilevel and deformity correction surgeries demanded blended strategies, while minimally invasive procedures benefited from moldable DBM and granular ceramics. Cost-effectiveness and logistical feasibility strongly influenced material selection. In Japan, the lack of rhBMP-2 approval and limited bone bank infrastructure further constrained options, reinforcing pragmatic combinations such as "autograft plus ceramics" or "DBM plus ceramics."

Conclusions: No single graft material is universally optimal. Reliable spinal fusion requires context-specific selection and combination strategies tailored to biological, mechanical, and regional factors. In Japan, strengthening bone bank systems and establishing robust domestic clinical evidence are essential. Future integration of regenerative grafts and next-generation biomaterials will require careful regulatory adaptation and cost-effectiveness validation.

Background: Rheumatoid cervical spondylitis (RCS) is a potentially devastating manifestation of rheumatoid arthritis (RA), typically presenting as atlantoaxial instability, basilar invagination, and/or subaxial subluxation. Despite modern disease-modifying antirheumatic drugs and biologics, established cervical instability often progresses and may result in myelopathy, brainstem compression, vertebrobasilar insufficiency, or sudden death. Many patients remain minimally symptomatic until late, emphasizing the need for structured surveillance and timely surgical referral. This review aimed to synthesize contemporary evidence on the epidemiology, imaging evaluation, risk stratification, and management of RCS and outline a pragmatic screening and treatment framework in the biologic era.

Methods: We performed a narrative review of the English-language literature using PubMed and major rheumatology and spine journals. Topics included the prevalence and natural history of cervical involvement in RA, mechanisms of instability, radiographic assessment (anterior/posterior atlantodental interval, Ranawat and Redlund-Johnell indices, cervicomedullary angle), clinical predictors of neurological decline, and outcomes of contemporary medical and surgical strategies.

Results: Cervical involvement remains common in RA, with atlantoaxial instability, basilar invagination, and subaxial subluxation often coexisting and following a characteristic progression. Many patients demonstrate radiographic instability without neurologic deficit, whereas a subset develops myelopathy or catastrophic injury. Radiographic parameters and clinical grading systems correlate with neurological status and recovery and inform timing of surgery. Modern disease-modifying antirheumatic drugs/biologic regimens reduce but do not abolish RCS progression. Pattern-specific stabilization procedures, including C1-C2 fusion, occipitocervical fusion, and subaxial instrumentation, generally yield pain relief, neurologic improvement, and durable fusion but carry meaningful perioperative risk.

Conclusions: RCS remains an important cause of preventable myelopathy and mortality in RA. Routine cervical screening of high-risk patients, appropriate advanced imaging, and early referral for stabilization before fixed deficits are critical to optimizing outcomes.

Bone growth stimulators serve as a critical adjunct in spinal-fusion procedures, particularly in patients at risk of nonunion or delayed healing. This review analyzes three primary modalities: biological, electrical, and ultrasound-based stimulators. Biological stimulators, including bone morphogenic proteins and platelet-rich plasma, use growth factors to promote osteogenesis but carry risks such as ectopic bone formation and inflammatory responses. Electrical stimulators, such as direct current stimulation and pulsed electromagnetic fields, leverage the piezoelectric properties of bone to activate osteogenic pathways and have indicated significant efficacy in promoting fusion in high-risk populations. Low-intensity pulsed ultrasound offers a noninvasive alternative that accelerates bone healing through mechanical and angiogenic pathways. The review also evaluates the preclinical application of bone growth stimulators in animal models, exploring the integration of advanced biomaterials to further enhance osteogenesis. Future research should prioritize optimizing the efficacy, safety, and cost-effectiveness of these modalities to improve spinal-fusion outcomes.

Background: Sagittal alignment is increasingly recognized as a key determinant of functional recovery after lumbar spine surgery; however, its role in degenerative lumbar disease remains variably reported. While alignment principles are well-established in adult spinal deformity, their applicability to routine degenerative procedures has not been quantitatively synthesized.

Methods: A systematic review and meta-analysis of 23 original clinical studies (1,837 adults) was performed. Eligible studies reported postoperative sagittal or spinopelvic parameters-pelvic incidence (PI) -lumbar lordosis (LL) mismatch, sagittal vertical axis, LL, pelvic tilt, or segmental lordosis-and at least one validated clinical outcome (Oswestry Disability Index, visual analogue scale/numerical rating scale, 12-Item Short Form Health Survey, EuroQol Five Dimensions, Core Outcome Measures Index, Japanese Orthopaedic Association). Continuous data were converted to log-odds ratios (ORs) (Chinn method) to enable unified pooling. Random-effects models were applied for disability and pain outcomes. Subgroup analyses assessed fusion versus decompression, PI-LL versus other alignment metrics, and short-term versus long-term follow-up.

Results: Eight studies contributed disability outcomes, yielding a pooled OR of 0.33 (95% confidence interval [CI] 0.16-0.65), indicating a 67% reduction in the odds of significant postoperative disability in aligned patients. Five studies contributed pain data, producing a pooled OR of 0.39 (95% CI 0.25-0.61), corresponding to a 61% lower likelihood of persistent postoperative pain. Fusion procedures demonstrated stronger alignment-associated benefit (OR 0.34) compared with decompression alone (OR 0.56). PI-LL-based studies showed consistent predictive value (OR 0.48), and the alignment effect increased with long-term follow-up (>12 months; OR ~0.28). Qualitatively, 87% of studies reported positive alignment-outcome associations.

Conclusion: Restoration of physiological sagittal alignment significantly improves postoperative disability and pain across degenerative lumbar procedures. Alignment correction should be considered a central element of surgical planning in both fusion and decompression.

Background: Percutaneous laser disc decompression (PLDD) is a minimally invasive treatment option for carefully selected patients with lumbar disc herniations (LDH) whose condition does not respond to conservative therapy but who may not require surgical decompression. Although PLDD has been increasingly adopted, reported outcomes vary widely across studies. This systematic review and meta-analysis aimed to evaluate the effectiveness and safety of PLDD in adults with LDH.

Methods: A systematic search of PubMed, Scopus, and Web of Science was conducted through November 2025. Adult PLDD studies reporting clinical outcomes were included. Random-effects models pooled continuous and binary outcomes. Primary outcomes were visual analog scale (VAS) improvement and clinical success. Secondary outcomes were Oswestry Disability Index (ODI) change, reoperation rates, and complications. Heterogeneity was assessed with I², and risk of bias with the Risk of Bias in Non-randomized Studies of Interventions.

Results: Fifteen publications reporting 14 unique PLDD cohorts were included. Eight studies (n=506) reported VAS outcomes, showing a pooled pain reduction of 4.33 points on a 0-10 scale (95% confidence interval [CI] 3.03-5.64; I²=98.8%). Three studies (n=128) reported ODI outcomes, with a pooled improvement of 20.1 points, but with substantial uncertainty (95% CI −21.7 to 61.9; I²=99.6%). Five studies (n=298) reported clinical success, yielding a pooled success rate of 73.8% (95% CI 55.9%-86.2%; I²=91.0%). The pooled reoperation rate across eight cohorts (n=650) was 10.3% (95% CI 6.3%-16.5%; I²=65.8%), and the pooled complication rate across ten studies (n=750) was 1.3% (95% CI 0.4%-3.9%; I²=1.0%). Most studies had moderate risk of bias due to non-randomized, single-arm designs.

Conclusions: PLDD is associated with meaningful pain reduction and moderate clinical success with a very low complication rate in selected patients with LDH. Functional outcomes and reoperation rates varied across studies. Further high-quality comparative research is needed to better define long-term results and optimal patient selection.

Introduction: Laminoplasty (LP) is widely used to treat cervical spondylotic myelopathy (CSM) with degenerative spondylolisthesis (DS), but predictors of postoperative outcomes remain unclear. This study aimed to identify factors associated with neurological recovery after LP in patients with CSM and DS.

Methods: We retrospectively reviewed 136 patients who underwent LP for CSM between 2005 and 2020. Of these, 29 patients (20 men, 9 women) with DS at the responsible level were included. The responsible level was defined as the segment showing intramedullary signal change or cerebrospinal fluid space obliteration on magnetic resonance imaging. The mean age was 71.7 years (range: 50-87), with a mean follow-up of 5.5 years (range: 2-12). Patients were grouped on the basis of achievement of a ≥50% recovery rate (RR) in the Japanese Orthopaedic Association (JOA) score, defined as the minimum clinically important difference (MCID). Radiographic parameters, including C2-7 alignment, C2-7 range of motion (ROM), C7 slope, slip distance, segmental ROM, and disc height at the responsible level, in addition to Pfirrmann grade, were compared.

Results: The mean JOA RR was 50.2%, with 66% achieving MCID. No statistically significant differences were found between the two groups in terms of C2-7 alignment, C2-7 ROM, C7 slope, slip distance, segmental ROM, or Pfirrmann grade. However, preoperative disc height was significantly greater in the Good Improvement group (5.9 mm) than in the Poor Improvement group (4.8 mm) (p=0.03).

Conclusions: Greater preoperative disc height was associated with better neurological recovery, suggesting its potential utility as a simple prognostic marker in CSM with DS.

Introduction: Spinal instrumentation surgery is increasingly being performed in aging populations; however, comprehensive data regarding the nationwide trends and perioperative safety associated with these procedures in Japan remain limited. This study aimed to evaluate the epidemiological characteristics and complication profiles of adult spinal instrumentation surgery using the Japanese Spinal Instrumentation Society Database (JSIS-DB).

Methods: A retrospective observational study was conducted using JSIS-DB data from 2018 to 2022. Adults aged ≥18 years who underwent spinal surgeries involving instrumentation across intervertebral levels were included. Data for demographic characteristics, diagnosis, surgical procedure, operative time, blood loss, and complications within 14 days of surgery were analyzed. The primary outcome was the overall perioperative complication rate, whereas the secondary outcomes included complication rates stratified by age and pathology.

Results: A total of 28,832 cases were analyzed (mean age: 67.3±14.4 years; males: 48.7%). The most common diagnosis was degenerative disease (62.9%), followed by spinal deformity (15.4%), trauma (15.2%), tumors (3.5%), and infection (2.6%). The most frequently performed procedure was posterior lumbar interbody fusion (40.8%), followed by posterior or posterolateral fusion (32.6%). The overall complication rate was 11.0%. The specific complication rates were as follows: dural tears, 2.5%; nerve root disorders, 1.4%; epidural hematomas, 1.1%; surgical-site infections, 0.8%; spinal cord disorders, 0.4%; and mortality, 0.1%. Patients aged ≥90 years showed a significantly higher complication rate (18.6%, p<0.001). The complication rates by pathology were as follows: deformities, 13.9%; infections, 13.4%; tumors, 13.3%; trauma, 12.3%; and degenerative diseases, 9.8% (p<0.001).

Conclusions: This nationwide registry-based study successfully visualized the real-world practices and risk profiles of adult spinal instrumentation surgery in Japan. Elderly patients and those with deformities, infections, or tumors showed significantly higher perioperative risks, highlighting the need for enhanced preoperative assessments and perioperative care. These findings provide foundational data to improve the safety and quality of spinal surgery.

Introduction: The Japanese Society for Spine Surgery and Related Research (JSSR) developed a national web-based registry system, integrating it with the Japanese Orthopaedic Association National Registry (JOANR/JSSR-DB) to systematically collect data on spinal and spinal cord surgeries and complications. This study aimed to report on the establishment of JOANR/JSSR-DB, and evaluate the epidemiology of spinal and spinal cord surgery in Japan, in addition to the frequency and characteristics of perioperative complications, on the basis of data from JOANR/JSSR-DB 2022

Methods: This registry-based study analyzed prospectively collected data in all patients who underwent spinal surgery at JSSR-certified institutions between April 1, 2022 and March 31, 2023. A total of 158,263 cases (89,358 men and 68,905 women; mean age 66.6 years) from 1,032 facilities were included. Data included demographics, diagnoses, surgical procedures, use of intraoperative supportive technologies, intraoperative and 30-day postoperative complications, and systemic complications.

Results: Of the total patients, 143,085 (90.4%) underwent initial surgery, 3,712 (2.3%) staged surgery, and 11,301 (7.1%) reoperation/additional surgery. The most prevalent diagnoses were lumbar spinal canal stenosis (51,472, 32.5%), lumbar disc herniation (26,256, 16.6%), and cervical spondylotic myelopathy (15,394, 9.7%). The most common surgical procedures were posterior lumbar interbody fusion (10,910, 6.9%), posterior spinal fusion (10,826, 6.8%), and balloon kyphoplasty (8,274, 5.2%). The frequencies of intraoperative, postoperative, and systemic complications were 2.6% (4,107 patients), 2.7% (4,316 patients), and 1.8% (2,782 patients), respectively. Overall, the complication frequency was 6.5% (10,313 patients).

Conclusions: A comprehensive spine and spinal cord surgery registry was established in Japan, and a comprehensive study was conducted on diseases, surgeries, and complications related to spinal surgeries performed in 2022 in Japan. Ongoing registry-based studies are expected to enhance evidence-based practices, reduce complications, and maintain high medical care standards.

Level of evidence: 4

Introduction: There have been several prognostic tools proposed for determining spinal epidural abscess patient outcomes. One such method is the "mortality in spinal infection" scoring system. In this study, we aim to externally validate this score within the New Zealand population.

Methods: We identified all patients who were admitted to a tertiary referral centre with a diagnosis of spinal epidural abscess between February 2009 and January 2022. The mortality in spinal infection score was calculated for all patients. We developed a receiver operating characteristic curve and a calibration plot to externally validate the score.

Results: A total of 140 patients with spinal epidural abscesses met the criteria for inclusion in our study. Within the one-year follow-up period, 18 patients died while 122 survived. In total, 105 patients underwent surgical intervention, while 35 patients were managed nonoperatively. In total, 5/15 (33%) of patients with scores ≥11 died compared with 13/125 (10%) of those with scores <11 (odds ratio 4.3, 95% confidence interval [CI] 1.3-14.6, p=0.03). This threshold had high specificity (0.92) and negative predictive value (0.90) but lower sensitivity (0.28) and positive predictive value (0.33). The area under the curve of the receiver operating characteristics plot for mortality in spinal infection scoring and death (0.67, 95% CI 0.57-0.79) did not meet the prespecified criterion of an area under the curve >0.80 for acceptable prediction.

Conclusions: In this cohort, the mortality in spinal infection-20 score demonstrated limited ability to discriminate between those patients who died vs those who survived at one year post follow-up. Prospective multicentre data collection may improve the development of predictive tools.

Background: Sarcopenia is known as a risk factor for poor outcomes. However, its association with clinical outcomes after spinal surgery remains unclear. The purpose of this study was to investigate the impact of sarcopenia on clinical outcomes after lumbar decompression surgery using the Asian Working Group of Sarcopenia (AWGS) 2019 criteria.

Methods: A total of 135 patients who underwent lumbar decompression surgery were included in this study. Clinical outcomes were assessed preoperatively and at the one-year follow-up, including the Visual Analog Scale (VAS) for lumbar pain, VAS for leg pain, VAS for leg numbness, the Oswestry Disability Index (ODI), the Roland-Morris Disability Questionnaire (RDQ), and the satisfaction rate. Patients were divided into three groups: the normal, sarcopenia, and severe sarcopenia groups, according to the AWGS 2019 criteria.

Results: The proportion of patients with sarcopenia was 27.4% and that of severe sarcopenia was 11.5%. The body mass index in the normal group was higher than in the sarcopenia and severe sarcopenia groups. Improvement in clinical outcomes was observed in all three groups. Preoperatively, ODI and RDQ in both sarcopenia groups were higher than those of the normal group; this difference remained at one year postoperatively.

Conclusions: Lumbar decompression surgery effectively reduces lumbar pain, leg pain, and leg numbness, but patients with sarcopenia might be more likely to experience persistent functional impairments compared to those without sarcopenia.

Introduction: Progressive spinal deformity is frequently observed in children with flaccid-type neuromuscular disease. Reports evaluating activities of daily living (ADL) or quality of life (QOL) for those with flaccid-type neuromuscular disease with spine deformity (fNMS) are limited. In Japan, there is no standard patient-based questionnaire in Japanese to evaluate ADL or QOL for fNMS. We have translated the Muscular Dystrophy Spine Questionnaire (MDSQ) from English into Japanese and evaluated the reliability and validity of the Japanese version of the MDSQ.

Methods: We explained the Japanese MDSQ to patients at our regular outpatient clinic. The patients completed the questionnaire at home and mailed it to us. The questionnaire was administered twice, separated by two-week intervals, to establish reliability. We calculated the total score of the Japanese MDSQ and analyzed its correlation with whole spine X-ray parameters. We also analyzed the correlations between the 36-Item Short-Form Survey for QOL and the Japanese MDSQ scores.

Results: We analyzed results from 26 patients (average age, 13 years). Those with Duchenne muscular dystrophy (11), spinal muscular atrophy (9), and other congenital diseases were included. The averaged scoliosis Cobb angle was 67.2°, pelvic obliquity (PO) was 19°, the maximum kyphosis Cobb angle was 62.3°, and spinal pelvic obliquity (SPO) was 27.4°. The total Japanese MDSQ scores at the first and second responses were 74.9±21.3 and 75.9±20.9, respectively. The reliability of the Japanese MDSQ was excellent, with an intraclass correlation coefficient of 0.90. Total MDSQ scores correlated with scoliosis Cobb angle, PO, and SPO.

Conclusions: The Japanese MDSQ demonstrates excellent reliability and reflects the radiographic parameters of spinal and pelvic deformities in those with fNMS. It appears to be a sufficiently robust instrument for evaluating ADL in children with fNMS with spinopelvic deformity in Japan.

Introduction: In patients with lumbar degenerative diseases (LDDs) presenting with drop foot, surgical outcomes have traditionally been assessed by neurological recovery, while studies using patient-reported outcomes (PROs) have been limited. This study retrospectively investigated whether recovery of drop foot influences improvements in PROs following surgery for LDDs.

Methods: We retrospectively analyzed 54 surgically-treated patients with LDDs presenting with drop foot, with a minimum follow-up of 1 year. PROs were evaluated using the visual analog scale, the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), the Zurich Claudication Questionnaire, and the Roland-Morris Disability Questionnaire (RMDQ).

Results: Patients were divided into recovered (R, manual muscle test [MMT] ≥3) and unrecovered (U, MMT <3) groups. Demographics, etiology, and responsible roots were comparable. The R group had a higher proportion with a preoperative tibialis anterior (TA) MMT score of 2 (64.3% vs. 34.6%, p=0.029) and a shorter paralysis duration (31.7 vs. 70.9 days, p=0.001). Preoperative TA MMT was slightly higher in the R group, which improved to 4.4 at final follow-up compared with 1.3 in the U group (p=0.001). At final follow-up, the R group showed significantly better JOABPEQ walking ability and RMDQ scores. Minimal clinically important difference achievement rates were consistently higher in the R group, although most differences were not statistically significant.

Conclusions: TA recovery in drop foot due to LDDs was associated with better walking ability and favorable PRO trends. Although statistical significance was limited, timely intervention and muscle recovery appear crucial for optimizing mid-term functional outcomes.

Introduction: Cement-augmented pedicle screws (CAPS) are increasingly used in surgeries for osteoporotic vertebral fractures (OVFs); however, cement leakage (CL) remains a concern. Lateral-view (LV) fluoroscopy, the conventional method for monitoring cement injection, has limited sensitivity in detecting early leakage. The oblique-view (OV) method may provide improved detection, although its role in CAPS fixation remains unclear.

Methods: Data from 116 patients and 535 screws who underwent CAPS fixation for OVFs using the LV or OV method were retrospectively compared. Patient demographics, surgical factors, and CL incidence were analyzed. A novel computed tomography-based grading system for segmental vein CL was developed as follows: grade 0 (no CL), grade 1 (≤10 mm), grade 2 (>10 mm without exceeding the anterior border or ≤10 mm beyond the anterior border), and grade 3 (>10 mm beyond the anterior border).

Results: Baseline demographics and surgical factors were comparable between the groups. Overall, CL was observed in 56% of the patients and 20.9% of the screws. The screw-based incidence of CL was significantly lower in the OV group than in the LV group (15.0% vs. 22.9%, p=0.047), although the CL severity did not differ. Intraoperative CL detection was significantly more effective in the OV group than in the LV group (37.2% vs. 91.7%, p<0.01), including grade 1 and 2 cases, and 67% of leakages were identified within 0.4 mL of injection. No major complications, such as pulmonary embolism, occurred.

Conclusions: The OV method enhanced the intraoperative detection of CL during CAPS fixation for OVFs, facilitating the early recognition of minor leakage and reducing the overall leakage frequency without increasing the incidence of severe complications. These findings support the clinical utility of the OV method and the proposed grading system, which may guide safe cement injection in patients with osteoporosis.

Introduction: The paucity of research concerning the conservative management of spinal cord and cauda equina schwannomas and meningiomas complicates the determination of surgical necessity and its optimal timing. This study aimed to elucidate the clinical and imaging characteristics of schwannomas and meningiomas in the thoracolumbar and lumbar spine that support long-term conservative management strategies.

Methods: A retrospective case series of 159 patients with magnetic resonance imaging-confirmed schwannomas or meningiomas was conducted. Patients were categorized into operative (n=125) and conservative (n=34) groups based on whether surgery was performed within one year of diagnosis. Tumor characteristics, clinical symptoms, and imaging data were systematically analyzed. Tumor occupancy was modeled using an ellipsoidal formula to estimate spinal canal involvement. A receiver operating characteristic curve analysis determined the optimal cutoff for predicting treatment decisions. Multivariate logistic regression was employed to identify factors influencing treatment choice.

Results: Tumor occupancy emerged as a critical determinant, with a cutoff of 0.42 predicting treatment choice with a sensitivity of 0.79 and a specificity of 0.89 (area under the curve=0.87). Logistic regression analysis revealed significant associations for tumor occupancy (adjusted odds ratio [OR]=9.6×10^-5; 95% confidence interval [CI]=6.2×10⁻⁷-5.3×10⁻³; p<0.001), presence of numbness or leg pain (OR=0.022; 95% CI=9.8×10⁻⁴-0.18; p=0.002), and male gender (OR=0.19; 95% CI=0.038-0.83; p=0.037). No significant associations were observed for age, decreased manual muscle testing, or imaging heterogeneity.

Conclusions: Prolonged conservative management is feasible for female patients who do not have leg pain or numbness and tumors with low occupancy. A tumor occupancy threshold of 0.42 may serve as a valuable clinical indicator to guide treatment decisions, promoting individualized, symptom-driven management strategies tailored to patient characteristics.

Introduction: Selective nerve root block is commonly performed under fluoroscopy, but reports of ultrasound (US) guidance remain limited. Although hydrodissection has shown favorable outcomes in peripheral nerves, few studies have evaluated the lumbar nerve root. Therefore, we aimed to evaluate the injectate distribution, reproducibility, safety, and clinical efficacy of US-guided hydrodissection of the lumbar nerve root (US-HNR) using fluoroscopic assistance.

Methods: US-HNR was performed in 46 patients with lumbar radiculopathy between January and September 2025. A standardized injectate (contrast agent 3 mL, saline 6 mL, and lidocaine 1% 1 mL; total 10 mL) was administered. Distribution was classified into four types under fluoroscopy. The Numerical Rating Scale (NRS), Oswestry Disability Index (ODI), and patient satisfaction were evaluated pre- and postprocedurally.

Results: Contrast evaluation was possible in 40 patients. Distribution patterns were localized within the periradicular region of the target nerve root in 30%, ipsilateral epidural in 38%, contralateral epidural in 25%, and contralateral nerve root in 8%, suggesting localized spread in one-third of cases. NRS improved significantly from 7.1 to 5.0 at 1 week, 4.2 at 1 month, and 3.8 at 3 months (all p<0.001), with responder rates of 52%, 60%, and 58%. ODI improved from 42 to 32 at 1 month and 28 at 3 months (p<0.01), with responder rates of 54% and 62%. No serious complications were observed. Two experienced transient radiating pain during injection.

Conclusions: US-HNR was safe and feasible, avoiding radiation and direct nerve puncture. This simple technique showed favorable clinical outcomes and may represent a promising treatment for lumbar radiculopathy.

Introduction: To determine whether preoperative thoracolumbar mobility predicts early upper instrumented vertebra-adjacent fracture (eUIVAF) after lower thoracic (LT) -pelvic fusion for adult spinal deformity (ASD) in elderly patients, in whom fracture-type proximal junctional failure is most prevalent.

Methods: Seventy-four ASD patients aged ≥40 years who underwent corrective fusion spanning ≥6 vertebrae (2018-2024) by a single surgeon were analyzed. Sagittal parameters were measured on preoperative standing radiographs and supine computed tomographic (CT) images. ΔTLK and ΔTK were defined as angular changes in thoracolumbar (T10-L2) and thoracic (T5-T12) kyphosis between standing and supine positions. eUIVAF was defined as a new vertebral fracture at or adjacent to the UIV within 3 months. Given that all eUIVAFs occurred in patients aged ≥70 years who underwent LT-pelvic fusion (n=40), this elderly LT-pelvic subgroup constituted the primary analytic cohort for group comparisons, logistic regression, and receiver operating characteristic (ROC) analyses.

Results: eUIVAF occurred in 14 of 74 patients (18.9%), exclusively among those aged ≥70 years with LT-pelvic fusion. In this subgroup, ΔTLK was greater in patients with eUIVAF than in those without (17.6°±8.0° vs 7.2°±7.0°, p<0.001), whereas ΔTK did not differ significantly. In a multivariable model including ΔTLK and ΔTK, only ΔTLK remained associated with eUIVAF (odds ratio, 1.27; 95% confidence interval, 1.09-1.47). ROC analysis for ΔTLK showed excellent discrimination (area under the curve, 0.90), with an optimal cutoff of 12°.

Conclusions: In elderly patients undergoing LT-pelvic fusion, preoperative ΔTLK was a strong radiographic predictor of eUIVAF. ΔTLK ≥12° identified a high-risk group, although this ROC-derived cutoff from a small single-center cohort without internal validation remains exploratory and requires confirmation in larger multicenter studies. Given that ΔTLK can be obtained from routine preoperative standing radiographs and supine CT, incorporating it into preoperative planning may help tailor fixation range, construct design, and correction magnitude in elderly ASD patients.

Introduction: Lumbar microdiscectomy (MLD) is a safe and effective treatment for lumbar disc herniation with low complication rates. However, short-term perioperative complications remain a concern for at-risk patients. Chronic corticosteroid use has been linked to impaired healing and infection in other spinal procedures, yet its impact in MLD remains poorly defined. This study aimed to evaluate the association between chronic corticosteroid use and 30-day complications following elective lumbar MLD.

Methods: A retrospective cohort study was conducted using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2016 to 2023. Data were collected from adult patients (≥18 years) undergoing microdiscectomy. Patients with fusion procedures or systemic illnesses were excluded. Corticosteroid use was defined according to the NSQIP variable as systemic use within 30 days prior to surgery. A 3:1 nearest-neighbor propensity score matching was performed on key covariates. Multivariable logistic regression was adjusted for race, ethnicity, operative year, and inpatient status.

Results: Of 64,380 eligible patients, 2,439 (3.8%) used chronic steroids. Post-matching yielded a cohort of 9,648 patients with well-balanced characteristics. Chronic steroid users had significantly higher odds of 30-day readmission (odds ratio [OR]=1.41; 95% confidence interval [CI]: 1.12-1.77; p=0.003), pneumonia (OR=2.21; 95% CI: 1.08-4.44; p=0.026), deep vein thrombosis (OR=2.04; 95% CI: 1.00-4.08; p=0.046), and sepsis (OR=3.18; 95% CI: 1.60-6.37; p<0.001). Operative time, transfusion rates, and length of stay were similar. Most patients were discharged home, with no differences in disposition between groups.

Conclusions: Chronic corticosteroid use is independently associated with increased risks of postoperative sepsis, deep vein thrombosis, pneumonia, and readmission following lumbar microdiscectomy. These findings highlight the importance of perioperative risk stratification and surveillance in this subgroup. Surgeons should consider proactive risk mitigation strategies, such as perioperative infection prophylaxis, pulmonary hygiene, and enhanced thromboprophylaxis, when managing these patients. Further prospective studies are warranted to enhance outcomes in this population.

Introduction: The role of pelvic stabilizing muscles, particularly the gluteus muscles, remains largely unexplored in the context of sagittal alignment. Understanding the relative vulnerability of each muscle group during the sequential breakdown of sagittal alignment is thus important. We hypothesize that gluteal muscle degeneration precedes or accompanies the failure of pelvic compensation in sagittal malalignment, making it a key indicator of early decompensation. Here, we examine which trunk or pelvic muscles demonstrate the greatest deterioration in morphology and quality across progressive stages of sagittal alignment decompensation, and aim to identify muscle-related predictors of spinopelvic malalignment.

Methods: In this cross-sectional study, we analyzed 204 outpatients stratified into groups based on standing whole-spine radiographic parameters: normal (sagittal vertical axis [SVA] ≤50 mm and pelvic tilt [PT] ≤20°), compensated (SVA ≤50 mm and PT >20°), and decompensated (SVA >50 mm). We measured computed tomography-derived cross-sectional area (CSA) and Hounsfield unit (HU) values for the paravertebral (erector spinae and multifidus), psoas, gluteus medius, and gluteus maximus muscles. Group comparisons were performed using non-parametric tests, and logistic regression models were used to identify independent predictors of alignment deterioration.

Results: Both gluteal and paraspinal muscles exhibited significant declines in CSA and HU values across worsening alignment stages, whereas the psoas muscle did not. In multivariate analyses, reduced HU values of the gluteus medius and maximus and decreased paraspinal CSA values were independently associated with abnormal and decompensated alignment. Notably, the gluteus medius HU value was positively associated with compensation maintenance, whereas the gluteus maximus HU value had a negative association.

Conclusions: Degeneration of the gluteal muscles, especially in muscle quality, is strongly associated with the breakdown of sagittal alignment compensation. Our results suggest the gluteal musculature is a useful early biomarker and therapeutic target in preventing age-related spinal imbalance.

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.

Introduction: Patient-facing websites operated by medical societies are crucial for disseminating reliable health information; however, their real-world usage and effectiveness are often unquantified. This study investigated the user engagement and demographics of "Scoliosis Town," a patient education website developed by the Japanese Scoliosis Society, to evaluate its performance.

Methods: We conducted a retrospective analysis of the website's traffic data from June 1, 2018, to March 31, 2023 (58 months), using Google Analytics. Key metrics included the number of users and sessions, user demographics (age and gender), access patterns (device type and acquisition channel), and popular content.

Results: The website attracted 2,333,184 users over 3,111,702 sessions. The primary users were female (68.1%), with the 35-44 age group being the largest demographic (29.4%), suggesting the site effectively reached its target audience of patients' mothers. The most frequently viewed pages were those detailing the "causes" and "treatment" of scoliosis. Most users accessed the site via mobile devices (83.3%), primarily through organic search (88.0%), with traffic peaking on weekday evenings.

Conclusions: The Japanese Scoliosis Society patient education website successfully reached its intended demographic of caregivers and was actively used to seek fundamental information about scoliosis. This study demonstrates the value of medical society-led digital platforms and validates web analytics as a powerful tool for assessing real-world patient information needs.

Introduction: The "Smiley Face Rod" (SFR) method is an effective direct repair technique for lumbar spondylolysis. However, three-dimensional rod contouring is technically demanding, particularly in patients with a high body mass index (BMI), where deep soft tissue obscures anatomical landmarks.

Technical Note: We report a technique using a patient-specific three-dimensional (3D) -printed model to create a sterilized "Reference Rod" template. A 27-year-old male with bilateral L5 spondylolysis and severe obesity (BMI 39.8 kg/m²) underwent SFR repair. A 3D model was printed from preoperative computed tomography data. A malleable template rod was contoured on this model to perfectly fit the lamina and spinous process and then sterilized. Intraoperatively, the final titanium rod was bent to match this sterile Reference Rod. This allowed for a "one-pass" insertion through the interspinous ligament with optimal bony contact, eliminating intraoperative trial-and-error.

Conclusions: The 3D-printed Reference Rod technique is a feasible approach that may facilitate rod contouring for SFR in challenging high-BMI cases by providing a tangible template to address the visualization and geometric limitations of conventional fluoroscopy.