Weight Loss Before Total Joint Arthroplasty Using a Remote Dietitian and a Mobile Application: A Multicenter Randomized Controlled Trial.

Abstract

Background: Many surgeons recommend weight loss for patients with obesity before total joint arthroplasty (TJA), but few studies have evaluated weight loss interventions. This study compared weight loss using a remote dietitian and a mobile application (app) with weight loss using standard care for patients with severe obesity before TJA.

Methods: This multicenter randomized controlled trial included 60 subjects with a body mass index (BMI) of 40 to 47 kg/m 2 who had been scheduled for primary total hip or knee arthroplasty from September 2019 to January 2023. The mean age was 61 years, 67% were women, and the mean BMI was 44 kg/m 2 . The control subjects (n = 29) received standard care; the intervention subjects (n = 31) completed video calls with dietitians and used a mobile app for 12 weeks preoperatively. Weights and surveys were collected at baseline and 12 weeks, with 87% follow-up. Weight loss, patient-reported outcomes, complications, revisions, and reoperations were compared. The mean follow-up was 1.8 years.

Results: The intervention subjects lost more weight (-4.1 versus -2.1 kg, p = 0.22) and had larger decreases in BMI (-1.4 versus -0.9 kg/m 2 , p = 0.36 than the controls, but not significantly so. The intervention subjects had higher odds of achieving a BMI of <40 kg/m 2 (odds ratio = 1.9, p = 0.44), but not significantly so. There were no significant differences in the mean change in the Hip disability and Osteoarthritis Outcome Score, the Knee injury and Osteoarthritis Outcome Score, or the Lower Extremity Activity Scale score. At baseline, only 11% had seen a dietitian in the last 3 months. Most subjects (83%) felt that video calls were helpful. There were no differences in complications between the groups; there was a patellar fracture in the control group and a deep venous thromboembolism in the intervention group.

Conclusions: A preoperative weight loss intervention using a dietitian and a mobile app was feasible and viewed favorably among patients. Remote dietitians and mobile apps may address gaps in access to obesity treatment before TJA. While the intervention subjects lost more weight and were more likely to achieve a BMI of <40 kg/m 2 , the differences were not significant. More intensive interventions may be needed to achieve enough weight loss for clinically important improvements in TJA.

Level of evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.