Total Joint Arthroplasty in the Morbidly Obese: How Body Mass Index ≥40 Influences Patient Retention, Treatment Decisions, and Treatment Outcomes

Abstract

Background: The United States is in an obesity epidemic. Obesity has multiple common comorbid conditions, including lower extremity arthritis. We sought to examine the course of treatment for a population with body mass index (BMI) ≥40 kg/m2 and osteoarthritis (OA) of the hip or knee. We investigated decision criteria that influenced arthroplasty surgeons to recommend nonoperative management vs total joint arthroplasty (TJA). For those patients who ultimately received TJA, we compared outcomes in this population to those with BMI <40 kg/m2. Methods: This study retrospectively reviewed 158 new patients with BMI ≥40 kg/m2 and moderate/severe OA of the hip or knee. Demographics, comorbidity profiles, and weight loss were compared between groups that underwent TJA and those that did not. The arthroplasty database was used to identify patients who underwent TJA during 2016-2018 (N = 1473). Comorbidities, readmissions, surgical site infections, and overall complications were compared between those with BMI ≥40 kg/m2 and BMI <40 kg/m2. Results: About 51.3% of new patients with BMI ≥40 kg/m2 and moderate/severe OA did not return for a second clinic visit. Of those who did return, 42.9% eventually underwent surgery. BMI was higher in single visit patients vs those with multiple visits (49.5 vs 46.3 kg/m2, P <40 kg/m2, overall complications were not higher in the BMI ≥40 kg/m2 group, although surgical site infections were higher in those undergoing total hip arthroplasty with BMI ≥40 kg/m2 (0.3% vs 3.1%, P <40 kg/m2 and only 20% of surgeries were performed on patients who had achieved this proposed cutoff.