A Study on Clinical Efficacy and Differences between the Endoscopic Fusion and the Oblique Lateral Interbody Fusion in the Treatment of Single-Segment Meyerding garde I and II spondylolisthesis

Objective： This study aims to compare the clinical outcomes and differences between the endoscopic fusion and the oblique lateral interbody fusion in the management of Meyerding grade I and II lumbar spondylolisthesis. Methods: . A prospective observational study was conducted, enrolling 86 patients with lumbar spondylolisthesis who were admitted to our institution between January 2021 and June 2024. Based on patients’ autonomous selection of surgical strategies, the cohort was stratified into the endoscopic fusion group (n = 45) and the oblique lumbar interbody fusion (OLIF) group (n = 41). All patients completed a postoperative follow-up period of no less than 12 months.The following outcomes were compared between the two groups: operative time, intraoperative blood loss, postoperative drainage volume, postoperative bed rest duration, postoperative hospital stay, spondylolisthesis reduction distance, increase Intervertebral space height, postoperative complication incidence, postoperative Visual Analogue Scale (VAS) score, and Oswestry Disability Index (ODI) score. Lumbar fusion status was assessed for all patients in both groups at each follow-up visit, in accordance with the Bridwell classification system. According to the modified MacNab classification, the excellent and good rates of the two groups of patients at the last follow-up were evaluated and compared. Results: Patients in the OLIF group exhibited superior perioperative outcomes in terms of operative time (167.09±50.59min vs 112.31±26.95min), intraoperative blood loss (167.73±42.27mL vs 114.19±24.54mL), postoperative drainage volume (154.67±22.13mL vs 98.69±10.91mL), and increase in intervertebral space height(4.46±1.79mm vs 5.17±1.65mm）compared with the endoscopic fusion group, with all differences reaching statistical significance (P<0.05). Both patient groups demonstrated effective therapeutic outcomes in the treatment of lumbar spondylolisthesis, with no statistically significant difference in efficacy (P>0.05). Nevertheless, regarding the restoration of intervertebral space height, the OLIF procedure exhibited superior performance (5.17±1.65mm vs 4.4±1.79mm, P<0.05). Furthermore, postoperative low back pain occurred less frequently in patients who underwent the OLIF procedure, with a statistically significant difference observed between the two groups (P < 0.05). However, with prolonged follow-up duration, pain severity in both groups showed a trend toward improvement (F _time =58.62, P _time <0.001). Additionally, statistically significant differences were observed in both intergroup comparisons and group-time interactions (P<0.05). Regarding neurological function outcomes, no statistically significant difference was observed between the two groups (P>0.05). However, neurological function outcomes of patients in both groups showed a trend toward improvement over the follow-up period. The main effect of time was statistically significant in both groups (F _time =185.62, P<0.001). Regarding lumbar fusion status, at the 3-month postoperative follow-up, the fusion rate in the OLIF group was significantly higher than that in the endoscopic fusion group (41.46% vs 20.00%, P<0.05). However, with prolonged follow-up duration, no statistically significant difference was observed in the fusion rates between the two groups (P>0.05). Based on the modified MacNab criteria, the excellent-to-good rate in the OLIF group was higher than that in the endoscopic fusion group (85.37% vs 80.00%). Postoperative complications in both groups were predominantly concentrated in nerve injury, but no statistically significant difference was observed between the two groups (P>0.05). Conclusion: This study demonstrated that for patients with Meyerding grade I and II lumbar spondylolisthesis, the oblique lateral interbody fusion technique effectively alleviates postoperative low back pain. Furthermore, it exhibits more favorable and statistically significant effects in reducing operative duration, increasing intervertebral space hight, minimizing intraoperative blood loss and postoperative drainage volume, and enhancing postoperative therapeutic outcomes .