Comparison of Short-Term Efficacy of Single-port Endoscopic Discectomy and Unilateral Biportal Endoscopic Discectomy in the Treatment of L5/S1 Lumbar Disc Herniation at Michigan State University Grade 2

Background and Objective Single-port endoscopic (open surgical excision [OSE]) discectomy and unilateral biportal endoscopic (UBE) discectomy have demonstrated effective therapeutic outcomes in lumbar disc herniation (LDH) treatment. However, there is a lack of clear guidelines for selecting surgical techniques for LDH at Michigan State University (MSU) grade 2. This study aimed to compare the clinical efficacy and imaging data of OSE and UBE in treating L5/S1 LDH at MSU grade 2. Methods This retrospective cohort study enrolled patients with L5/S1 LDH who were admitted between September 2022 and July 2024. Patients were stratified into OSE (n = 97) and UBE (n = 119) groups according to the surgical technique performed. Each group was further stratified into two subgroups based on the MSU classification of LDH (types 2B and 2C). All patients were followed for a minimum of one year. Perioperative parameters, serum levels of prostaglandin E2 (PGE2) and transthyretin (TTR), visual analog scale (VAS) score, Oswestry Disability Index (ODI), postoperative complication rate, recurrence rate, and modified MacNab criteria at the final follow-up were recorded and compared between groups to assess clinical efficacy. Surgical outcomes were further evaluated using radiological parameters, including bone loss volume (BLV), disc height index (DHI), lumbar range of motion (ROM), sagittal translation (ST), and paraspinal muscle relative cross-sectional area (RCSA). Results No significant difference was observed in the operation time and hospital stay between the two groups (P > 0.05). Incision length, intraoperative blood loss, and number of intraoperative fluoroscopy exposures were significantly lower in the OSE group than in the UBE group (P < 0.05). During a minimum of 1 year of postoperative follow-up, no statistically significant difference was observed in the VAS scores of the waist and legs and ODI at any assessed time point between the two groups (P > 0.05). However, the VAS scores of incision-related pain in the OSE group were lower than those in the UBE group on days 1 and 3 postoperatively (P < 0.05). No significant difference was observed between the two groups in complication rates, recurrence rates, modified MacNab scores, DHI, ROM, ST, erector spinae RCSA, or psoas major RCSA within 1 year postoperatively (P > 0.05). However, the OSE group demonstrated significantly better outcomes than the UBE group with respect to bone loss, serum PGE2, TTR levels, and multifidus RCSA (P < 0.05). Conclusion OSE and UBE can achieve good therapeutic effects in the treatment of grade 2 LDH at the L5/S1 segment in patients with MSU. Compared with UBE, OSE demonstrated advantages, including reduced surgical trauma, less early postoperative incision pain, a lower perioperative inflammatory response, improved preservation of bone structure, and enhanced protection of the multifidus muscle, reflecting higher surgical precision and a more minimally invasive profile. In clinical practice, treatment should be individualized based on the specific conditions of each patient.