Comparison of three different surgical techniques in cases of single-level lumbar spinal stenosis: A retrospective clinical study

Objectives: The current trend in lumbar spinal stenosis (LSS) surgery emphasizes minimally invasive approaches that minimize tissue trauma and avoid post-operative instability while achieving sufficient decompression and reducing intraoperative bleeding and hospital stay. This study aimed to retrospectively compare the widely used Full Endoscopic Interlaminar Decompression (FEID) and Microsurgical Bilateral Decompression through Unilateral Approach (MBDU) techniques with the conventional Posterior Segmental Instrumentation-Laminectomy (PSEL) in single-level LSS, to determine their relative advantages and limitations. Methods: Between 2016 and 2022, 188 patients with single-level LSS who underwent surgery using one of the three techniques were included. Demographic and perioperative data, including age, sex, symptom duration, operative time, intraoperative blood loss, and hospitalization duration, were recorded. Functional and radiological outcomes were assessed by comparing pre- and post-operative radicular Visual Analog Scale (VAS) scores, oswestry disability index (ODI) values, and transverse canal diameter ratios on lumbar magnetic resonance imaging. Results: Operative time was similar between the FEID and MBDU groups but significantly shorter than in the PSEL group. Blood loss and hospitalization duration were lowest in FEID, higher in MBDU, and highest in PSEL. No difference was found among the groups in radicular VAS scores. ODI scores were lower in FEID and MBDU than in PSEL, with early post-operative advantage favoring FEID. Decompression was greatest in PSEL, while FEID and MBDU achieved comparable canal expansion. Conclusion: In single-level LSS without pre-operative axis deviation or instability, FEID and MBDU provided more favorable functional outcomes. Although PSEL – performed with concomitant fusion in our cohort – resulted in greater post-operative canal expansion, it did not translate into meaningful improvements in functional outcomes.