Multilevel Decompression Surgery for Degenerative Lumbar Spinal Canal Stenosis Is Similarly Effective with Single-level Decompression Surgery

Study Design. Retrospective case series. Objective. The purpose of this study was to investigate the outcome of multilevel posterior decompression surgery for degenerative lumbar spinal stenosis compared with single-level surgery. Summary of Background Data. The clinical outcomes of multilevel decompression surgery are still controversial because previous studies have not been designed to randomize or adjust the patient background. Materials and Methods. A retrospective review of prospectively collected data from 659 surgically treated lumbar spinal stenosis patients with a minimum 2-year follow-up was performed. Among them, we compared baseline and 2-year postoperative patient-reported outcomes (PROs) including the Visual Analog Scale and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire scores of 122 patients who underwent three or more levels of surgery (M group) and 304 patients who underwent single-level surgery (S group). Further analyses were performed of 116 paired patients from both groups who were propensity score matched by age and baseline PROs. Results. The number of perioperative complications including extradural hematoma, surgical site infection, and spinal fluid leakage [M vs. S: 10 (8%) vs. 19 (6%), P=0.47], and frequency of revision surgery [5 (4%) vs. 23 (8%), P=0.10] were similar between the two groups. In the analysis of propensity score-matched patients, there were comparable improvements in the Visual Analog Scale score for lower back pain (2.6 vs. 2.4, P=0.55), buttock-leg pain (3.1 vs. 3.4, P=0.48), and buttock-leg numbness (2.9 vs. 2.9, P=0.77) in both groups. There were also similar improvements in the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire scores including lower back pain, lumbar function, walking ability, and mental health domains, except for the social life function domain (20.7±26.5 vs. 28.0±27.5, P=0.04). Conclusions. Despite the longer surgical time and a larger volume of estimated blood loss, multilevel decompression surgery showed similar improvement to that of single-level surgery in terms of recovery of PROs and frequency of revision surgery. Multilevel decompression surgery provides good clinical outcomes with acceptable complication and revision rates when selecting appropriate patient and spinal levels.