The isthmic corridor- a novel anatomical approach for L5-S1 postero-lateral endoscopic lumbar discectomy (PELD)

Abstract

Background: Lumbosacral junction (L5-S1) with its distinctive anatomical features, presents a unique challenge to endoscopic spine surgeons.1–7 The choice between interlaminar and postero-lateral (transforaminal) routes for L5-S1 endoscopic discectomy remains controversial. Purpose: Describe a novel isthmic approach for postero-lateral endoscopic lumbar discectomy (PELD) at L5-S1 level and critically analyze the surgical results. Study Design: Technical note. Case series. Patient Sample: 25 patients with symptomatic L5-S1 disc herniation. Outcome Measure: Demographics, radiological features, bony anatomy, and clinical outcomes. Methods: Each patient underwent postero-lateral endoscopic lumbar discectomy utilizing isthmic approach. The patient data was prospectively collected and retrospectively analyzed. Results: Average pain score for back pain and leg pain significantly improved from pre-op level of 3.09 and 7.81 to 2.17 and 2.15, respectively. Statistically significant improvement was also observed in post-op ODI score (pre-op = 58, post-op 33.85, p ≤ 0.00001). There were no intra-op complications of nerve or thecal sac injury. Conclusion: Combining isthmus trajectory to L5-S1 postero-lateral endoscopic discectomy adds to the applicability of this already well established surgical procedure. Isthmic approach offers a safe and effective anatomical corridor for performing endoscopic discectomy via transforaminal route, even in individuals with high iliac crest. Keywords: Endoscopic discectomy, Lumbosacral junction, Postero-lateral approach