Improvement in low back pain following endoscopic decompression for spinal stenosis.

Introduction: Lumbar spinal stenosis (LSS) commonly presents with neurogenic claudication and low back pain (LBP). Decompression surgery effectively relieves leg symptoms, but its impact on LBP remains inconsistent. While full-endoscopic decompression has emerged as a minimally invasive alternative, evidence regarding its specific effect on LBP is limited. Research question: To evaluate the improvement in LBP following full-endoscopic decompression for LSS with or without low-grade degenerative spondylolisthesis (SPL), and to identify the clinical and radiological factors influencing these changes. Materials and methods: Consecutive patients undergoing full-endoscopic decompression for LSS between 2017 and 2024 were retrospectively analyzed. Pre- and postoperative clinical and radiographic status were assessed for patients with a follow-up of ≥1 year. The primary outcome was reaching a minimally important clinical difference (MCID) in Visual Analogue Scale (VAS) for LBP. Logistic regression analyses were performed to identify factors associated with achieving MCID, and subgroup analysis assessed the impact of low-grade SPL on outcomes. Results: Sixty-four patients (mean age 63.8 years, 53.1% female) with mean follow-up of 24.9 months were included. 35.9% had low-grade SPL. MCID was achieved in 84.5% of patients at 12 months and 79.7% at last follow-up. Greater baseline back pain severity was associated with achieving MCID (OR = 2.31, 95% CI 1.31 - 4.08, p = 0.004), and low-grade SPL was not associated with inferior clinical outcomes. Discussion and conclusion: Full-endoscopic decompression for LSS is associated with clinically meaningful improvement in LBP in most patients, and the presence of low-grade SPL does not appear to negatively affect outcomes.