Minimally Invasive Decompression With Noninstrumented Facet Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion for Stenosis Associated With Grade 1 Lumbar Degenerative Spondylolisthesis

Study Design: Retrospective matched cohort study. Summary of Background Data: With a growing interest in minimally invasive spine surgery (MIS), the question of which technique is the most advantageous for patients with low-grade degenerative lumbar spondylolisthesis (DLS) still remains unclear. Objective: To compare patient-reported outcomes, perioperative morbidity, and rates of reoperation between MIS decompression with either unilateral noninstrumented facet fusion (MIS-F) or with transforaminal interbody fusion (MIS-T) for grade 1 DLS. Methods: Twenty patients who underwent MIS-T and 20 patients with MIS-F were matched based on age, sex, and preoperative ODI, VAS back, and VAS leg. All patients had DLS with at least 4 millimeters of translation on standing radiographs. Exclusion criteria included prior level surgery, multilevel instability, disk impinging on the exiting nerve root, spondylolisthesis from significant facet arthropathy, or foraminal compromise from disk collapse. ODI, VAS back, VAS leg, and patient satisfaction measured by the North American Spine Society questionnaire were tracked at 3, 6, 12, and 24 months postoperatively. Minimum clinically important differences and substantial clinical benefits were calculated. Results: MIS-F and MIS-T resulted in decreased ODI at 3, 6, and 12 months following the index procedure. Sixty percent of MIS-F and 83% of MIS-T patients reached minimum clinically important difference at 1 year postoperatively; however, using the threshold of 30% ODI reduction from baseline, 67% of MIS-F and 83% MIS-T ( P = 0.25) achieved this goal. Forty-three percent of MIS-F and 59% of MIS-T patients met substantial clinical benefits. Satisfaction at 1 year, measured by a score of 1 or 2 on the North American Spine Society questionnaire, was 64% for MIS-F and 83% for MIS-T. Conclusions: MIS-F and MIS-T are effective treatment options for spinal stenosis associated with low-grade DLS. Both techniques result in comparable patient-reported outcomes and satisfaction up to 2 years and have similar long-term reoperation rates. More evidence is required to delineate optimal selection characteristics for MIS-F versus MIS-T.