LAUSR

OBJECTIVES To discuss the surgical outcome of using trepan to treat single segment Ossification of Ligamentum Flavum (OLF) under the endoscope and evaluate the application value of the new surgical treatment. MATERIALS AND METHODS Patients who underwent surgery for single segment OLF in the medical centre from January 2015 to June 2018 were included in a retrospective analysis. 26 patients accepted visual trepan decompression under the endoscope. The same surgical team performed posterior spinal canal resection and decompression for 11 patients with single segment OLF. The Japanese Orthopaedic Association (JOA) scores, JOA improvement rate, and visual analogue scale (VAS) of both groups were observed in the follow-up. CT was used to evaluate patients' residual area ratio of the vertebral canal. Meanwhile, operation time, length of stay, amount of bleeding and hospitalisation cost in both groups were also observed and recorded. RESULTS The average follow-up time was 8.9±2.7 months. The average operation time was 100.6±35.0 min in the research group and 140.5±28.3 min in the control group. In the final follow-up, the average improvement rate of JOA scores was 78.3% and 84.2% in the research group and the control group, respectively. The average vertebral canal area of residual rate which was less than 50% before operation in both groups all recovered to 100% after operation. In addition , the VAS of all patients was obviously reduced in the final follow-up,. CONCLUSIONS The visual trepan technique has a certain feasibility to treat single segment OLF under the spinal endoscope. It has the advantage of less trauma, faster recovery and less expenditure, but more samples and long-term follow-up are required to further evaluate the clinical effect and safety of this surgical method.