Clinical efficacy of staged percutaneous endoscopic posterior decompression for multi-segment thoracic ossification of the ligamentum flavum

English Keywords:Ossification of the ligamentum flavum  Percutaneous spinal endoscopy  Staged treatment  Multi-segment

English Abstract:

  【Abstract】 Objectives: To investigate the clinical efficacy of staged percutaneous endoscopic posterior decompression for treating multi-segment thoracic ossification of ligamentum flavum(mTOLF). Methods: The clinical data of 16 patients with mTOLF who were treated with staged percutaneous endoscopic posterior decompression at our hospital between June 2021 and June 2023 were retrospectively analyzed, including 9 males and 7 females, aged 46-67(55.4±6.8) years old. The preoperative imaging examinations of the patients indicated multi-segment ossification of ligamentum flavum, including double segments in 14 cases and triple segments in 2 cases. The responsible segments were as follows: upper thoracic spine(T1-T4) in 4 cases, middle thoracic spine(T5-T9) in 6 cases, and lower thoracic spine(T10-T12) in 24 cases. Staged percutaneous endoscopic posterior decompression was performed for mTOLF, targeting only one responsible segment in each surgery. The operative time, blood loss, hospitalization days, and complications were recorded. The Oswestry disability index(ODI) and the modified Japanese Orthopaedic Association(mJOA) 11-point scale scores were recorded preoperatively, on 3d postoperatively, and at the final follow-up, and the mJOA improvement rate at the final follow-up was calculated. Statistical analysis was performed to evaluate the clinical efficacy. The spinal canal area and the anterior-posterior spinal canal diameter were measured on CT images preoperatively, on 3d postoperatively, and at the final follow-up to evaluate the improvement of imaging findings. Results: All the 16 patients successfully completed the surgery, and no cerebrospinal fluid leakage or permanent lower limb paralysis occurred except for one dural tear during operation. The operative time was 80-205min(150.2±36.1min), blood loss was 30-70mL(50.3±12.4mL), hospitalization days were 9-15d(10.8±1.8d) and the follow-up time ranged from 9-20(14.3±3.2) months. The mJOA scores and ODIs before surgery, on 3d after surgery, and at the final follow-up were 5.7±1.3, 7.1±1.3, 8.5±1.4, and (41.4±1.8)%, (17.8±1.6)%, (15.6±1.3)%, respectively, which were both significantly improved on 3d postoperatively and at final follow-up compared with those values before operation(P<0.05). The mJOA recovery rate was 28.6%-100%[(56.1±19.3)%], and according to the mJOA evaluation criteria, the outcomes were classified as excellent in 3 cases, good in 9 cases, fair in 4 cases, and poor in no case, with an excellent and good rate of 75.0%. The spinal canal area and anterior-posterior diameter before surgery, on 3d after surgery, and at the final follow-up were 76.7±12.5mm2, 159.9±22.1mm2, 157.7±21.6mm2, and 7.4±0.5mm, 15.5±0.9mm, 15.3±0.9mm, respectively. Both the spinal canal area and anterior-posterior diameter on 3d postoperatively and at the final follow-up significantly increased compared to preoperative values(P<0.05). Conclusions: Staged percutaneous endoscopic posterior decompression for treating mTOLF is safe and effective, and yields satisfactory clinical outcomes.