The clinical efficacy of unilateral biportal endoscopic treatment for lumbar spinal stenosis with preservation of the ligamentum flavum

Background As a minimally invasive surgical approach for treating lumbar spinal stenosis, Unilateral Biportal Endoscopy (UBE) is receiving significant attention from clinical practitioners. Conventional UBE surgery involves the removal of the ligamentum flavum, and to date, there is no research on UBE techniques that preserve the ligamentum flavum. Method A retrospective analysis was conducted on 100 patients with lumbar spinal stenosis (LSS) who underwent UBE treatment from January 2022 to March 2024. The surgical techniques of decompression of the lumbar canal while preserving the ligamentum flavum using UBE technology were summarized. Patients were divided into two groups based on whether the ligamentum flavum was preserved during surgery: the preservation group with 40 patients, and the removal group with 60 patients. The intraoperative surgical time and blood loss of the two groups were compared, as well as perioperative Visual Analogue Pain Scores (VAS), Oswestry Disability Index (ODI), and complications such as dural tears and epidural hematoma. The difference in radiological decompression between the two groups was assessed using the cross-sectional area of the dural sac on lumbar MRI. Results The average surgery time for the group with the ligamentum flavum preserved was (50.13±8.45) minutes, and the intraoperative blood loss was (30.57±6.64) ml. For the group with the ligamentum flavum removed, the average surgery time was (66.47±7.26) minutes, and the intraoperative blood loss was (58.70±6.19) ml. Compared to the group with the ligamentum flavum removed, the group with the ligamentum flavum preserved had a shorter surgery time and less blood loss, with these results being statistically significant (P < 0.01). There was no difference in the VAS scores and ODI scores between the two groups at 3 days and 6 months postoperatively. The postoperative dural sac cross-sectional area for the ligamentum flavum preserved group and the ligamentum flavum removed group was 164.31±26.35 mm²and 170.92±27.68 mm², respectively, with no statistically significant difference (P = 0.24). The incidence of postoperative complications was 1.92% in the ligamentum flavum preserved group and 5.77% in the ligamentum flavum removed group, which was not statistically significant (P = 0.61). Conclusion The technique of unilateral biportal endoscopy (UBE) for lumbar spinal stenosis, which preserves the ligamentum flavum, can reduce complications, surgical time, and blood loss, while simultaneously providing favorable surgical outcomes. It is recommended to preserve the ligamentum flavum as much as possible when using UBE for the treatment of patients with lumbar spinal stenosis.