Objective
This study aimed to evaluate the stability of cement-augmented pedicle screws in patients with osteoporosis of the thoracolumbar spine, with a focus on reducing mechanical failures compared with non-augmented screws.
Methods
A retrospective analysis was conducted on 119 patients who underwent thoracolumbar fusion surgery between 2011 and 2022. The incidence of mechanical failures—including pull-out, screw loosening, and cage protrusion—was compared between patients treated with cement-augmented pedicle screws and those without augmentation.
Results
Cement augmentation was associated with a significant reduction in overall mechanical failures. The incidence of mechanical failure was significantly lower in the cement-augmented group compared with the non-augmented group (20.4% vs. 41.4%, p=0.018). Although individual complications such as pull-out, cage protrusion, and screw loosening were less frequent in the cement-augmented group, these differences were not statistically significant. However, the overall reduction in mechanical failures was statistically significant. Fusion rates were higher in the cement-augmented group than in the non-augmented group, although the difference was not significant (79.6% vs. 70.0%, p=0.337). Importantly, patients without mechanical failures had significantly higher fusion rates than those with failures (82.5% vs. 56.41%, p=0.0048).
Conclusions
Cement-augmented pedicle screws significantly reduce the risk of mechanical failures in thoracolumbar fusion surgery for patients with osteoporosis. Mechanical stability strongly influences fusion success, highlighting the importance of preventing mechanical failure to optimize surgical outcomes. These findings support cement augmentation as an effective strategy to enhance the durability of pedicle screw fixation and should be considered in surgical planning for patients with osteoporosis.

Purpose
This study evaluates the performance of Claude and GPT LLM Vision APIs for automated clinical questionnaire processing in spine surgery by comparing accuracy, efficiency, reproducibility, and cost-effectiveness.
Methods
Clinical questionnaires from 56 patients (336 total pages) were processed using a Python 3.12-based system incorporating PDF preprocessing, image enhancement via OpenCV, and direct LLM Vision analysis. Both models were evaluated on 26 questionnaire items (1,456 data points) using accuracy comparison, processing time measurement, token utilization analysis, and intra-class correlation coefficient (ICC) assessment through three independent iterations.
Results
GPT achieved 98.83% accuracy (1,439/1,456) compared to Claude's 97.94% (1,426/1,456). Both models processed questionnaires in 27 seconds per set, representing 68% time reduction versus manual entry (85 seconds). GPT demonstrated 59% cost advantage ($0.023 vs. $0.056 per questionnaire), while Claude showed superior reproducibility (ICC 0.98 vs. 0.96). GPT achieved 100% accuracy across 21 items versus Claude's 17 items. Error analysis identified predominantly handwriting recognition (52%) and image quality issues (28%), with 89% of errors successfully flagged for review.
Conclusions
Both models achieve clinical-grade performance exceeding 90% accuracy. GPT demonstrates superior accuracy and cost-effectiveness, while Claude provides better reproducibility. Model selection should be guided by institutional priorities regarding accuracy, reproducibility, and operational scale.

Purpose
To evaluate the association between lumbar lordosis and age using an AI-based automated measurement model applied to a large dataset of standing lateral spinal radiographs.
Materials and Methods
This retrospective study analyzed 904 high-quality radiographs selected from 2,397 images acquired between 2019 and 2021. Lumbar lordosis was defined as the angle between the superior endplates of L1 and S1 and automatically measured using a validated deep learning model. Subjects were categorized into nine age groups. One-way ANOVA compared lumbar lordosis across age groups, and Pearson correlation assessed the relationship between age and lumbar lordosis.
Results
Lumbar lordosis ranged from 0° to 84° (mean 45.9°±13.4°). The highest mean value was in the 10–19-year group (52.1°), and the lowest in the ≥80-year group (39.6°). Minimum values decreased to 0° in individuals aged ≥60 years. No significant differences were found across age groups (p=0.561). A weak but significant negative correlation was observed between age and lumbar lordosis (r=–0.247, p<0.0001).
Conclusions
AI-based automated measurement enabled efficient large-scale analysis and revealed a wide distribution of lumbar lordosis with a gradual age-related decline. These findings highlight the value of AI in spinal alignment assessment.

Purpose
Revision lumbar surgery following posterior decompression is technically challenging because epidural adhesions and altered anatomy increase the risk of complications during posterior re-entry. Surgical approaches that avoid the previously operated corridor may reduce these risks. Biportal endoscopic lumbar interbody fusion using an extraforaminal approach allows direct neural decompression and interbody fusion through a new surgical corridor, which may be advantageous in revision settings. However, clinical evidence regarding this technique in revision surgery remains limited. To evaluate the clinical and radiological outcomes of biportal endoscopic revision extraforaminal lumbar interbody fusion (BE-REFLIF) performed at lumbar segments previously treated with central decompression.
Materials and Methods
This study is Single-center retrospective case series.We retrospectively reviewed 20 consecutive patients who underwent single-level BE-REFLIF as revision surgery after prior central decompression between September 2017 and June 2024. Clinical outcomes were assessed using the visual analogue scale (VAS) for back and leg pain, the Oswestry Disability Index (ODI), and the EuroQol-5D (EQ-5D). Radiological outcomes included disc height, segmental alignment, lumbar lordosis, fusion status, and cage subsidence. Perioperative data and postoperative complications were also analyzed.
Results
Significant improvements were observed in all clinical outcome measures during follow-up. Mean VAS scores for back and leg pain and ODI decreased significantly over time (p < 0.001). Radiological analysis demonstrated significant restoration of disc height, improvement in segmental alignment, and maintenance of lumbar lordosis. Solid fusion was achieved in 85% of patients at the final follow-up, and cage subsidence occurred in 25% of cases without the need for reoperation. Perioperative complications included dural tears in 10% of patients, epidural hematoma in 5%, and surgical site infection in 5%, with no instrumentation-related failures.
Conclusions
Biportal endoscopic revision extraforaminal lumbar interbody fusion demonstrated favorable clinical and radiological outcomes in patients undergoing revision surgery after previous central decompression. By utilizing an extraforaminal corridor that avoids scarred posterior tissues, BE-REFLIF allows effective direct decompression and interbody fusion with an acceptable complication profile. This technique may represent a viable and less invasive option for selected patients requiring revision lumbar fusion.

Purpose
This study aims to identify risk factors and changes in spino-pelvic parameters associated with Sacroiliac (SI) joint degeneration.
Materials and Methods
This multicenter retrospective study included 472 patients who underwent fusion surgery at three hospitals between March 2021 and February 2024. SI joint degeneration was assessed using seven indicators: sclerotic changes, erosion, osteophyte formation, intra-articular bone formation, joint space narrowing, intra-articular gas formation, and subchondral cysts. CT scans were performed preoperatively and 6 months postoperatively. The patients were divided into two groups: those with progression of SI joint degeneration and those without. Standing whole spine lateral X-rays were used to measure a total of 10 spinopelvic parameters both preoperatively and at 6 months postoperatively. Statistical analysis was performed using two-sample t-tests and multivariable logistic regression.
Results
Among the 472 patients, 135 (28.6%) showed progression of SI joint degeneration. When comparing the two groups, age (p=0.022), alcohol consumption (p=0.001), smoking (p<0.001), and S1 involvement (p=.04) were associated with SI joint degeneration. Regarding spino-pelvic parameters, patients with SI joint degeneration exhibited significant changes in thoracic kyphosis (p=0.017) and pelvic tilt (p=0.049).
Conclusions
Sacrum fixation, smoking, alcohol consumption, and age can be significant risk factors for SIJ degeneration following lumbar fusion surgery.

Background
Neurogenic bladder dysfunction is a common and serious consequence of traumatic conus medullaris syndrome (T-CMS). Despite its clinical importance, predictive data for bladder outcomes after T-CMS remain limited. This study aimed to identify predictors of neurogenic bladder dysfunction at ≥2 years post-injury.
Methods
We retrospectively reviewed 39 patients with acute T-CMS treated at a single level I trauma center from 2004–2017 who underwent spinal surgery and had ≥2 years of follow-up. Bladder function at 2 years was categorized as complete dysfunction, incomplete dysfunction, or normal. Potential predictors included demographic factors, injury mechanisms, ASIA Impairment Scale grades, MRI timing, fracture level and type, canal diameter, occupying ratio, conus signal change (normal, edema, or edema with hemorrhage), edema length, time to surgery, and surgical approach. Univariate and multivariate analyses were performed.
Results
At final follow-up, 14 patients (35.9%) had complete bladder dysfunction, 12 (30.8%) had incomplete dysfunction, and 13 (33.3%) had normal function. Multivariate analysis identified edema with hemorrhage in the conus medullaris as the only independent predictor of bladder dysfunction.
Conclusions
Bladder dysfunction is highly prevalent after T-CMS. Hemorrhagic edema in the conus medullaris significantly increases the risk of long-term neurogenic bladder dysfunction.

Purpose
To evaluate the clinical and radiologic effects of switching from long-term bisphosphonate therapy to romosozumab in an elderly patient with severe osteoporosis and vertebra plana–type severe osteoporotic vertebral collapse, followed by transition to denosumab maintenance therapy.
Methods
An 85-year-old woman with a history of osteoporotic fractures and prolonged intravenous bisphosphonate therapy presented with an acute L2 compression fracture. Conservative management with a body cast was initiated, and romosozumab was introduced as a switching therapy when anabolic treatment was indicated. Thoracolumbar spine radiographs were obtained at presentation and at 1, 3, 7, and 12 months after injury. Computed tomography was performed at presentation and again at 7 and 12 months to assess fracture consolidation. Bone mineral density (BMD) was measured beginning at 18 months after injury and annually thereafter. Functional assessments were recorded throughout a 30-month follow-up period.
Results
During romosozumab therapy, the L2 vertebra plana–type severe osteoporotic vertebral collapse showed marked radiologic improvement, characterized by progressive intravertebral bone fill-in and gradual restoration of trabecular continuity without further loss of height. Serial follow-up CT and MRI demonstrated consolidation of the previously cavitated vertebral body, indicating substantial structural recovery rather than simple stabilization. Clinically, the patient experienced steady improvement in pain and ambulatory capacity. After completing six monthly doses of romosozumab, therapy was transitioned to denosumab. L2 bone mineral density improved from a T-score of –1.7 to –0.9, accompanied by gains in femoral BMD. No additional fragility fractures occurred throughout the follow-up period.
Conclusions
Switching from long-term bisphosphonate therapy to romosozumab resulted in improved BMD, progressive vertebral bone fill-in, and stabilization without further collapse in this elderly patient with severe osteoporosis. Although not established as a fracture-healing agent, romosozumab may serve as a practical anabolic option in selected cases, with denosumab maintenance ensuring ongoing skeletal protection.

Tethered cord syndrome (TCS) is a condition in which the spinal cord becomes pathologically stretched due to various congenital or acquired etiologies, leading to progressive neurological symptoms. While surgical detethering is the gold standard for pediatric patients, adult-onset recurrent TCS presents a significant surgical challenge. Reoperation carries substantial risks—including spinal cord injury, cerebrospinal fluid leakage, and a high rate of retethering—often resulting in suboptimal long-term outcomes. Recently, spine-shortening osteotomy (SSO) has emerged as an alternative technique to reduce spinal cord tension without direct manipulation of the neural elements. Here, we report a case of recurrent adult TCS associated with a lipomyelomeningocele, which was exacerbated by post-traumatic kyphosis from an L1 compression fracture. The patient was successfully treated with SSO at the L1 level. This case highlights the utility of SSO as a safe and effective alternative to conventional revision detethering, particularly in complex cases involving spinal deformity.

Purpose
Glomangiomas of the spine are exceptionally rare benign vascular tumors, frequently misdiagnosed as more common lesions such as schwannomas or meningiomas. Although most spinal glomangiomas exhibit benign behavior, the presence of a BRAF V600E mutations may indicate uncertain malignant potential. Accurate diagnosis and complete surgical excision are essential for favorable outcomes.
Methods
A 43-year-old male with left flank pain was evaluated with thoracic MRI and underwent surgical resection. Histopathological and molecular analyses were performed.
Results
Thoracic magnetic resonance imaging (MRI) revealed a 2.8 cm ovoid, hypervascular mass adjacent to left T10 transverse process, extending to the posterior hemithorax. Surgical resection was performed, and histopathological examination confirmed a glomangioma with positive smooth muscle actin (SMA) expression and a BRAF V600E mutation.
Conclusions
This case highlights the diagnostic challenge posed by paraspinal glomangiomas and emphasizes the importance of histopathological and molecular analysis in establishing the correct diagnosis. A review of the literature demonstrates that complete surgical excision remains the treatment of choice, with excellent prognosis. The identification of BRAF mutations may warrant closer follow up.

Adolescent idiopathic scoliosis refers to spinal deformity that develops from just before the onset of puberty until the completion of skeletal growth, and the primary goal of treatment is to achieve a well-balanced spine. In the late 1990s, advances in the anatomical understanding of the spine and the development of fixation instruments made posterior pedicle screw insertion feasible, thereby enabling the transmission of powerful corrective forces for deformity correction. Over the subsequent decades, accumulated clinical experience and outcomes have provided a deeper understanding of scoliotic curves and led to the establishment of effective principles for determining the extent of spinal fusion. However, these treatment principles are based on the unique biomechanics and procedural characteristics of scoliosis correction surgery, which can make them difficult to understand without sufficient explanation. In this review, we aim to describe these established treatment principles and surgical processes in detail using schematic illustrations and images. Although these principles will continue to undergo new challenges and validation over time, they will remain a meaningful reference point for those exploring alternative strategies.