Unilateral biportal endoscopic decompression for symptomatic thoracic ossification of the ligamentum flavum: a case control study

Thoracic ossification of the ligamentum flavum (OLF) is an uncommon disease that mostly occurs in East Asians. Laminectomy is often considered when patients develop neuro-related symptoms but may associate with treatment-related complications. This study aimed to evaluate the efficacy and safety of unilateral biportal endoscopic (UBE) decompression treatment in patients with symptomatic OLF.From January 2020 to January 2021, patients with spinal cord compression symptoms and imaging-defined single-level thoracic OLF were enrolled in this study and received UBE decompression treatment. Their pre- and postoperative neurological statuses were evaluated by the modified Japanese Orthopaedic Association (mJOA) score, Visual Analog Scale (VAS) for leg pain, and Frankel grade.Fourteen patients with an average age of 59.4 years were enrolled in the study. The mean operation time was 66.1 ± 15.4 minutes. Patients were followed up for at least one year after receiving the treatment. Our data suggested that their mJOA score (preop 6.2 ± 1.2, 1 year 8.5 ± 0.9; P < 0.001) and VAS score (preop 4.5 ± 2.0, 1 year 0.5 ± 0.9; P < 0.001) were significantly improved compared with that before operation. Cerebrospinal fluid leakage occurred in one patient, head and neck pain occurred in two patients, and hyperalgesia of lower limbs occurred in two patients. All these complications did not cause serious consequences.This primary study indicated that the UBE decompression treatment can achieve satisfactory clinical results in patients with thoracic OLF at single level and provide an alternative treatment option.