A novel endoscopic retroperitoneal approach for debridement in lumbar infectious spondylodiscitis at L4-5: a clinical series and technical note

BACKGROUND: The L4-5 is one of the most commonly affected levels in lumbar infectious spondylodiscitis. Surgical intervention is typically required when conservative antibiotic therapy fails. For patients with extensive anterior abscess formation or widespread lesions, an anterior approach is often necessary. However, at the L4-5 level, the dense distribution of the lumbar plexus and the close proximity of the iliac vessels to the lesion demand particular caution when selecting an anterior approach. The present study aims to evaluate the feasibility, safety, and preliminary clinical efficacy of a novel endoscopic retroperitoneal approach for debridement combined with posterior percutaneous pedicle screw fixation in the treatment of lumbar infectious spondylodiscitis at the L4-5 level. METHODS: This retrospective study analyzed patients with L4-5 lumbar infectious spondylodiscitis who underwent endoscopic retroperitoneal debridement at our institution between July 2022 and July 2024. Baseline patient characteristics, operative time, intraoperative blood loss, postoperative lesion clearance, changes in inflammatory markers(e.g, C-reactive protein[CRP] and erythrocyte sedimentation rate[ESR]), complication rates, Visual analog scale (VAS) scores for back pain, Oswestry Disability Index (ODI) scores, kyphotic angle changes at the infected level, and radiological follow-up outcomes were recorded. RESULTS: Of the 28 patients, 27 (27/28, 96.43%) showed improvement in clinical symptoms. During follow-up, all patients demonstrated significant improvements in VAS scores and ODI scores compared to preoperative values (p<0.05). At the final follow-up, all patients exhibited a kyphotic angle change of less than 8°, and no spinal instability was observed. Computed tomography (CT) at the 12-month follow-up demonstrated intervertebral bone fusion in 26 cases (26/28, 92.86%). Postoperative inflammatory markers showed improved compared with preoperative levels (p<0.001). No infection recurrence or serious surgery-related complications were observed during the postoperative follow-up period. CONCLUSION: Endoscopic retroperitoneal debridement combined with posterior percutaneous pedicle screw fixation appears to be a safe and effective minimally invasive approach for treating L4-5 lumbar infectious spondylodiscitis. However, long-term efficacy requires further validation through prospective studies with larger sample sizes and extended follow-up periods.