Comparison of One-Hole Split Endoscopy and Unilateral Biportal Endoscopy for Far-Lateral Lumbar Disc Herniation at L5/S1: A Short-Term Retrospective Study

Objective：To compare the clinical efficacy and imaging outcomes of one-hole split endoscopy (OSE) versus unilateral biportal endoscopy (UBE) in the treatment of far lateral lumbar disc herniation (FLLDH) at the L5/S1 level. Methods: This study retrospectively included 47 patients with L5-S1 FLLDH who underwent surgical treatment at a single center between July 2022 and July 2024. Among them, 24 patients were treated using the UBE technique, while the remaining patients were treated using the OSE technique. Data recorded for all patients included hospital stay duration, operative time, intraoperative blood loss, fluoroscopy frequency, related complications, intervertebral foramen area (IVFA), height of the superior articular process (HSAP), lumbosacral lordosis angle (LLA), sagittal translation (ST), disc height (DH), visual analogue scale (VAS) scores, Oswestry Disability Index (ODI) scores, and clinical outcomes assessed by the Macnab criteria.Results: Both groups of patients achieved favorable clinical outcomes. Postoperative VAS scores and ODI indices at all follow-up time points showed significant improvement compared to preoperative values (P < 0.05), but there were no statistically significant differences in these scores between the two groups at any follow-up time point. One case in the OSE group experienced a dural tear. The excellent/good rates were 91.3% in the OSE group and 91.7% in the UBE group. There were no significant differences between the two groups in postoperative sagittal translation (ST), postoperative intervertebral foramen area (IVFA), lumbosacral lordosis angle (LLA), height of the superior articular process (HSAP), or disc height (DH). Postoperative imaging evaluation in both groups showed that sagittal translation (ST) and the lumbosacral lordosis angle (LLA) remained stable (P > 0.05), while significant changes were observed in other indicators: disc height (DH) decreased, intervertebral foramen area (IVFA) increased, and height of the superior articular process (HSAP) decreased (all P < 0.05). Regarding perioperative parameters, the operative time was shorter in the UBE group than in the OSE group, but the OSE group had advantages in incision length and intraoperative blood loss. Conclusion: Both UBE and OSE techniques are effective minimally invasive methods for the treatment of L5-S1 FLLDH.