Purpose
This retrospective study investigated the distinct clinical and radiographic drivers of early- versus late-onset proximal junctional kyphosis (PJK) following multilevel thoracolumbar (TL) fusion.
Methods
After applying the exclusion criteria (spinal infection, neuromuscular disease, age <50 years), the analysis included 136 patients who underwent ≥4-level TL fusion and were followed up for a minimum of 2 years. PJK was classified as early (≤6 months) or late (>6 months) onset. Patient-related factors, surgical variables, sagittal spinopelvic parameters, and preoperative magnetic resonance imaging findings were analyzed using multivariate logistic regression to identify independent predictors of early PJK.
Results
Among 24 patients (17.6%) who developed PJK, the early and late-onset groups included 13 and 11 patients, respectively. The early PJK group exhibited significantly greater preoperative and postoperative TL angles compared with the late group (preoperative: 23.03±13.83° vs. 9.67±9.67°, p=0.024; postoperative: 19.6±6.95° vs. 6.95±6.35°, p<0.001). The Pfirrmann grade of the L1–2 intervertebral disc was significantly higher in the early PJK group (3.92±0.95 vs. 2.81±0.60, p=0.006). No surgical variables differed significantly between the groups. Multivariate analysis confirmed greater postoperative TL angle and more advanced L1–2 disc degeneration as independent predictors of early PJK.
Conclusion
Early-onset PJK following multilevel TL fusion is primarily driven by regional biomechanical vulnerabilities, specifically residual postoperative TL kyphosis and advanced adjacent L1–2 disc degeneration, rather than by surgical variables. Meticulous evaluation of regional TL alignment and adjacent disc health during surgical planning is critical for risk stratification and prevention of early junctional failure.

Study Design
A retrospective diagnostic accuracy study was conducted using internal training and temporal validation cohorts.
Purpose
This study aimed to develop and validate sex-specific diagnostic nomograms for sarcopenia in patients with degenerative lumbar disease (DLD), based on body mass index (BMI), hand-grip strength (HGS), and computed tomography (CT)–derived lumbar muscle indices. Overview of Literature: The Asian Working Group for Sarcopenia (AWGS) 2019 algorithm requires appendicular skeletal muscle mass (ASM) measurement by dual-energy X-ray absorptiometry or bioimpedance analysis together with HGS and a physical performance test. These measurements are not always feasible in spine clinics, although a preoperative lumbar CT is routinely available.
Methods
A training set of 196 patients scheduled for lumbar surgery and a temporal validation set of 150 patients with DLD were analyzed. Sarcopenia was diagnosed according to the AWGS 2019 criteria. Sex-specific multivariable logistic regression was performed using BMI, HGS, psoas muscle index, paraspinal muscle index (PaMI), and gluteal muscle index (GMI), and the resulting models were translated into nomograms. Discrimination was assessed by the area under the receiver operating characteristic curve (AUC), calibration by calibration plots and mean absolute error (MAE), and the optimal cut-off was identified using the Youden index.
Results
The prevalence of sarcopenia was 62.2% (122/196) in the training set and 58.0% (87/150) in the validation set. In the training set, sarcopenic patients had significantly lower BMI (23.7±3.7 vs. 27.0±3.3 kg/m2), HGS (20.3±8.0 vs. 29.2±30.5 kg), PaMI (8.7±5.4 vs. 13.9±8.0), and GMI (26.1±5.7 vs. 30.9±6.2) than non-sarcopenic patients (all p<0.05). On validation, the male nomogram achieved an AUC of 0.958 with an MAE of 0.040, and the female nomogram achieved an AUC of 0.830 with an MAE of 0.021. The Youden index was 0.78 for males and 0.59 for females.
Conclusion
Sex-specific nomograms based on BMI, HGS, and CT-derived lumbar muscle indices provided accurate diagnosis of sarcopenia in patients with DLD without requiring whole-body ASM measurement or a physical performance test, offering a practical screening tool in the spine clinic.

Traumatic lumbar spondyloptosis is a rare entity associated with high-velocity mechanisms and is the most severe form of lumbar spondylolisthesis. Operative management is often required; however, the relative merits of reduction versus in situ fusion remain debated, largely owing to the technical difficulty of attaining satisfactory fracture reduction. In this report, we describe external femoral traction as a novel technique for closed reduction of traumatic lumbar spondyloptosis. A 27-year-old man presented after a tree he was cutting fell on him and was found to have T3–7 AO Spine (AOS) A1 fracture, L3 AOS B2 fracture, and L5 AOS C fracture. Neurologic exam was consistent with multilevel nerve root injury. Definitive treatment included bilateral femoral traction, open reduction, and combined anterior/posterior fixation. A multidisciplinary team including orthopedic surgery, plastic surgery, vascular surgery, and neurosurgery were involved. Complete reduction was obtained, and the patient experienced near-complete resolution of neurologic symptoms. This technique offers a unique solution to the challenge of traumatic lumbar spondyloptosis. Further study and follow-up are needed to confirm the utility and durability of this technique and the cranial extent of injury for which this technique might be applied.

Chondroma is a benign cartilaginous neoplasm, rarely encountered in the lumbar spine. We report a case involving a 70-year-old female who presented with lower limb radiating pain that started four years ago. Although no pronounced muscle weakness was noted, the patient experienced progressively worsening radiating pain in the L4 dermatome. Initial evaluation, including magnetic resonance imaging (MRI) performed at another medical facility, suggested a potential lesion associated with left L4–5 lumbar disc herniation. Despite non-surgical interventions, the patient experienced limited symptomatic relief, prompting her to seek further care at our clinic. Subsequent contrast-enhanced MRI conducted at our facility revealed a mass exhibiting peripheral rim enhancement surrounding the L4 nerve root. Suspecting a neurogenic tumor, we decided to perform surgical excision of the mass. Postsurgery, histopathological analysis confirmed the presence of hyaline cartilage with lobular architecture and chondrocytes in lacunae, leading to the conclusive diagnosis of chondroma. Following the surgical procedure, the previously reported radiating pain exhibited notable improvement.