FPIT046
Free Paper (Infection + Trauma)
Predicting Surgical Indications and Outcomes in Ankylosing Spondylitis Patients with Thoracolumbar Fractures: A Classification-Based Approach
Yong-Chan Kim, Sung-Min Kim, In-seok Son, Xiongjie Li, Young-Jik Lee, Maolin Jin
Department of Orthopaedic Surgery, Kyung Hee University Hospital at Gangdong, Kyung Hee University, Seoul, South Korea
Background: Surgical indications for PSO in unstable AS-related thoracolumbar fractures with sagittal imbalance remain unclear. This study evaluates surgical indications using a simplified classification— vertebral body (VB) vs. intervertebral space (IS)—and develops a predictive model from sagittal parameters.
Methods: 41 AS patients surgically treated for thoracolumbar fractures were reviewed. Fractures were classified as VB- or IS-type. Radiographic parameters, clinical outcomes, and complications were compared. Propensity score matching (1:1) using demographic and sagittal variables yielded 17 matched pairs. Logistic regression and decision tree analyses identified predictors for choosing PSO over posterior spinal fusion (PSF).
Results: VB-type fractures (n=24) showed greater sagittal imbalance (C7SVA 201.1 mm vs. 139.9 mm) and more frequent PSO (75% vs. 5.8%) than IS-type
94
fractures (n=17). After matching, VB-type fractures demonstrated larger corrections in C7SVA and LL, while clinical outcomes were similar. Complications occurred more often in VB/PSO cases but without statistical significance. Predictive modeling achieved 86.2% accuracy, identifying C7SVA > 180 mm— especially with LL < –10°—as the strongest indication for PSO.
Conclusion: VB-type fractures with marked imbalance benefit from deformity correction, whereas IS-type fractures are effectively managed with PSF. A classification-based algorithm using C7SVA and LL offers objective surgical indications for AS-related thoracolumbar fractures.