Obesity Does Not Negatively Affect Patient-perceived Outcomes After Cervical Disc Replacement for Disc Herniation.

Abstract

Retrospective review. To assess the impact of Body Mass Index (BMI) on patient-reported outcome measures (PROMs) after cervical disc replacement (CDR). BMI may affect PROMs after spine surgery. Primary CDR recipients for herniated disc(s) with BMI <40 were retrospectively selected from a single-surgeon registry. Cohorts were divided into non-obese (BMI <30) and obese (BMI ≥30). Intercohort in-hospital complication rates were compared through independent samples t tests. Pre/postoperative PROMs were compared between cohorts through multivariable regression accounting for demographic differences. Final follow-up dates between patients averaged 11.8 ± 9.3 months. PROMs assessed included Patient-reported Outcomes Measurement Information System-Physical Function, Neck Disability Index, Visual Analog Scale-Neck, Visual Analog Scale-Arm, and the 9-item Patient Health Questionnaire. Improvements in PROMs were evaluated and compared at each follow-up within cohorts through paired t tests. The magnitude of improvement in PROMs from preoperative baseline at 6-week follow-up (∆PROM-6W) and final follow-up (∆PROM-FF) along with achievement rates of minimum clinically important differences were compared between cohorts through multivariable regression accounting for demographic differences. Of 153 patients, 53 patients were noted as obese. Demographic differences included age, prevalence of hypertension and diabetes, and comorbidity burden scores (P ≤ 0.011, all). No significant variations in in-hospital complications were found. The non-obese cohort demonstrated improvements in all PROMs at 6 weeks and final follow-up periods (P ≤ 0.005, all). The obese cohort demonstrated improvements in all postoperative PROMs besides 9-item Patient Health Questionnaire at 6 weeks (P ≤ 0.015, all). After accounting for age and comorbidity variations, there were no significant intercohort differences in raw PROM scores, ∆PROM-6W, ∆PROM-FF, or minimum clinically important difference achievement rates. Regardless of BMI, patients experience significant improvements in physical function, disability, pain, and mental health after CDR for disc herniation. Patients with obesity do not suffer inferior patient-perceived outcomes after CDR. These findings may help surgeons counsel patients in the preoperative period.