Clinical Outcomes and Feasibility of Unilateral Biportal Endoscopic Decompression for Thoracic Ossification of the Ligamentum Flavum: A Retrospective Single-Center Study

Objective: Thoracic ossification of the ligamentum flavum (T-OLF) is a primary cause of thoracic myelopathy in East Asian populations. Unilateral biportal endoscopic (UBE) decompression offers a minimally invasive alternative. This study evaluates the feasibility and clinical outcomes of UBE decompression in patients with symptomatic T-OLF. Methods: We retrospectively reviewed patients who previously underwent UBE decompression for symptomatic T-OLF between August 2023 and December 2025. Demographic data, operative details, and perioperative complications of the patients were recorded. Clinical outcomes were evaluated using the modified Japanese Orthopaedic Association (mJOA) score, American Spinal Injury Association (ASIA) score, Visual Analogue Scale (VAS), and MacNab criteria. The mJOA recovery rate (RR) was also calculated. Results: Fifty-one patients (mean age 65.1 ± 9.4 years) were included. The majority had single-level lesions (n = 44, 86.3%), which were predominantly located at the T10–11 level (n = 24/60 segments, 40.0%). The mean operation time per segment was 97.5 ± 24.4 min, and mean blood loss was 29.4 ± 14.7 mL. The mean mJOA score improved significantly from 6.6 ± 1.0 preoperatively to 9.4 ± 0.6 at final follow-up (p < 0.001), yielding a 63.5% RR. Based on MacNab criteria, 82.4% of patients achieved excellent or good outcomes. Perioperative complications included intraoperative dural tears in 5 patients (9.8%), postoperative cerebrospinal fluid leakage in 3 patients (5.9%), transient neurological deterioration in 2 patients (3.9%), and epidural hematoma in 1 patient (2.0%). All complications were managed successfully without permanent neurological sequelae. Conclusions: UBE decompression was associated with postoperative neurological improvement and acceptable perioperative outcomes in selected patients with symptomatic T-OLF. Further comparative studies are required to determine its relative benefits compared with other decompression techniques.