Obese Patients Benefit, but do not Fare as Well as Nonobese Patients, Following Lumbar Spondylolisthesis Surgery: An Analysis of the Quality Outcomes Database

BACKGROUND: Given recent differing findings following 2 randomized clinical trials on degenerative lumbar spondylolisthesis (DLS) surgery, there is a need to better define how subsets of patients fare following surgery. OBJECTIVE: To investigate the impact of obesity on patient-reported outcomes (PROs) following DLS surgery. METHODS: A total of 12 high-enrolling sites were queried, and we found 797 patients undergoing surgery for grade 1 DLS. For univariate comparisons, patients were stratified by BMI >= 30 kg/m(2) (obese) and < 30 kg/m(2) (nonobese). Baseline, 3-mo, and 12-mo follow-up parameters were collected. PROs included the North American Spine Society satisfaction questionnaire, numeric rating scale (NRS) back pain, NRS leg pain, Oswestry Disability Index (ODI), and EuroQoL-5D (EQ-5D) Questionnaire. RESULTS: We identified 382 obese (47.9%) and 415 nonobese patients (52.1%). At baseline, obese patients had worse NRS back pain, NRS leg pain, ODI, and EQ-5D scores (P < .001, P = .01, P < .001, and P = .02, respectively). Both cohorts improved significantly for back and leg pain, ODI, and EQ-5D at 12 mo (P < .001). At 12 mo, similar proportions of obese and nonobese patients responded that surgery met their expectations (62.6% vs 67.4%, P = .24). In multivariate analyses, BMI was independently associated with worse NRS leg pain and EQ-5D at 12 mo (P = .01 and P < .01, respectively) despite adjusting for baseline differences. CONCLUSION: Obesity is associated with inferior leg pain and quality of life-but similar back pain, disability, and satisfaction-12 mo postoperatively. However, obese patients achieve significant improvements in all PRO metrics at 12 mo.