[Efficacy of unilateral biportal endoscopic technique for the treatment of thoracic myelopathy caused by short-segment ossification of the ligamentum flavum].

Abstract

Objective: To investigate the efficacy and safety of unilateral biportal endoscopy (UBE) for the treatment of thoracic myelopathy caused by thoracic ossification of the ligamentum flavum (TOLF). Methods: A retrospective case series analysis was conducted on the clinical data of 80 patients with short-segment (≤2 levels) TOLF who underwent UBE surgery at our institution between January 2020 and December 2024. The cohort comprised 44 males and 36 females with an age of (55.8±10.7) years (range: 34 to 76 years). Fifty-nine cases involved a single segment, and 21 cases involved two segments; 27 cases had concomitant dural ossification. Intraoperatively, a diamond burr was used to perform full-thickness drilling of the ossified ligamentum flavum, and the "floating technique" was applied in cases with dural ossification. Operative time, length of hospital stays, and perioperative complications were recorded. Spinal canal area and sagittal diameter were measured preoperatively, at postoperative day 3, and at the final follow-up. The Oswestry disability index (ODI) and Japanese Orthopaedic Association (JOA) score were assessed preoperatively, at postoperative day 3 and 3 months, and at the final follow-up. Repeated measures ANOVA was used to compare pre- and postoperative data, with pairwise comparisons adjusted using Bonferroni post-hoc tests. Results: All procedures were completed successfully without conversion to open surgery. The operative time was (141.4±44.6) min (range: 80 to 220 min), and the length of hospital stay was (11.7±5.5) d (range: 7 to 28 d). The follow-up period was (33.5±13.1)months (range: 12 to 60 months). Postoperative cerebrospinal fluid leakage occurred in 20 cases (25.0%, 20/80), all of which were associated with concomitant dural ossification or severe dural adhesion, and after conservative treatment, no cerebrospinal fluid leakage occurred. Epidural hematoma occurred in 3 cases (3.8%, 3/80), all of which were successfully managed by emergency endoscopic hematoma evacuation with subsequent recovery of muscle strength. Neurological deterioration due to improper drain placement occurred in 4 cases (5.0%, 4/80), all of which recovered to preoperative muscle strength levels by the final follow-up. Compared with preoperative values, spinal canal area and sagittal diameter were significantly increased at postoperative day 3 and at the final follow-up (all P<0.05). ODI and JOA scores showed significant improvement at all postoperative time points compared with preoperative values (all P<0.05). No symptom recurrence or neurological deterioration was observed at the final follow-up. Conclusions: UBE is an effective technique for the treatment of thoracic myelopathy caused by short-segment TOLF, achieving adequate spinal canal decompression and significant improvement in neurological function. Appropriate preoperative surgical approach planning and correct intraoperative decompression strategies are essential for ensuring surgical safety.