Predictors of the Best Outcomes Following Minimally Invasive Surgery for Grade 1 Degenerative Lumbar Spondylolisthesis

BACKGROUND: The factors driving the best outcomes following minimally invasive surgery (MIS) for grade 1 degenerative lumbar spondylolisthesis are not clearly elucidated. OBJECTIVE: To investigate the factors that drive the best 24-mo patient-reported outcomes (PRO) following MIS surgery for grade 1 degenerative lumbar spondylolisthesis. METHODS: A total of 259 patients from the Quality Outcomes Database lumbar spondylolisthesis module underwent single-level surgery for degenerative grade 1 lumbar spondylolisthesis with MIS techniques (188 fusions, 72.6%). Twenty-four-month follow-up PROs were collected and included the Oswestry disability index (ODI) change (ie, 24-mo minus baseline value), numeric rating scale (NRS) back pain change, NRS leg pain change, EuroQoL-5D (EQ-5D) questionnaire change, and North American Spine Society (NASS) satisfaction questionnaire. Multivariable models were constructed to identify predictors of PRO change. RESULTS: The mean age was 64.2 11.5 yr and consisted of 148 (57.1%) women and 111 (42.9%) men. In multivariable analyses, employment was associated with superior postoperative ODI change (beta-7.8; 95% CI [-12.9 to -2.6]; P = .003), NRS back pain change (beta -1.2; 95% CI [-2.1 to -0.4]; P = .004), EQ-5D change (beta 0.1; 95% CI [0.01-0.1]; P = .03), and NASS satisfaction (OR = 3.7; 95% CI [1.7-8.3]; P < .001). Increasing age was associated with superior NRS leg pain change (beta -0.1; 95% CI [-0.1 to -0.01]; P = .03) and NASS satisfaction (OR = 1.05; 95% CI [1.01-1.09]; P = .02). Fusion surgeries were associated with superior ODI change (beta -6.7; 95% CI [-12.7 to -0.7]; P = .03), NRS back pain change (beta -1.1; 95% CI [-2.1 to -0.2]; P = .02), and NASS satisfaction (OR = 3.6; 95% CI [1.6-8.3]; P = .002). CONCLUSION: Preoperative employment and surgeries, including a fusion, were predictors of superior outcomes across the domains of disease-specific disability, back pain, leg pain, quality of life, and patient satisfaction. Increasing age was predictive of superior outcomes for leg pain improvement and satisfaction.