The Effect of Body Mass Index on the Efficacy of Semaglutide Use at the Time of Total Knee Arthroplasty.

Background: This study evaluated the impact of semaglutide on postoperative complications following total knee arthroplasty (TKA) by body mass index (BMI) class.

Methods: A retrospective analysis of a national claims database was performed for patients undergoing primary TKA for osteoarthritis who had an active semaglutide prescription from January 2010 to April 2023. Patients were divided into non-obese (BMI < 30), obese (BMI 30.0 to 39.9), and morbidly obese (BMI > 40) groups. Semaglutide users were propensity score matched to non-users, yielding non-obese (7,402 versus 36,884), obese (4,034 versus 20,134), and morbidly obese (2,383 versus 11,853). Outcomes included 90-day medical complications, 90-day readmissions, and 90-day and 2-year implant-related complications. Univariate and multivariate regressions compared outcomes within BMI groups.

Results: In the non-obese group, semaglutide users had significantly lower odds of deep vein thrombosis (DVT) (odds ratio (OR) 0.68; 95% confidence interval (CI) 0.57 to 0.81; P < 0.001), pulmonary embolism (PE) (OR 0.49; 95% CI 0.34 to 0.70; P < 0.001), and pneumonia (PNA) (OR 0.69; 95% CI 0.53 to 0.89; P = 0.004). In obese patients, semaglutide users had significantly lower odds of 90-day periprosthetic joint infection (PJI) (OR 0.53; 95% CI 0.38 to 0.76; P < 0.001), 2-year PJI (OR 0.65; 95% CI 0.52 to 0.81; P < 0.001), 90-day revisions (OR 0.54; 95% CI 0.35 to 0.85; P = 0.008), DVT (OR 0.67; 95% CI 0.54 to 0.82; P < 0.001), pulmonary embolism (OR 0.39; 95% CI 0.23 to 0.62; P < 0.001), and PNA (OR 0.69; 95% CI 0.49 to 0.90; P = 0.008). In morbidly obese patients, semaglutide use was associated with significantly lower rates of 90-day aseptic loosening and myocardial infarction (both P < 0.001).

Conclusion: Our findings support a BMI-based approach to perioperative semaglutide use, particularly in patients who have a BMI > 30.