Do Overall Weight, Body Mass Index, or Clinically Significant Weight Changes Occur After Total Joint Arthroplasty? A Meta-Analysis of 60,837 Patients.

Background: Total joint arthroplasty (TJA) is well-recognized for improving quality of life and functional outcomes of patients with osteoarthritis; however, TJA's impact on body weight remains unclear. Recent trends have demonstrated a shift among TJA patients, such that patients who have higher body mass indices (BMIs) are undergoing this common surgery. Given this trend, it is critical to characterize the impact TJA has on body weight or BMI. This meta-analysis aimed to quantitatively assess whether patients lose, gain, or maintain body weight or BMI after TJA.

Methods: This study followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials databases were queried from inception through July 2022. The included studies: (1) reported on weight or BMI after elective, primary total hip arthroplasty (THA) or total knee arthroplasty (TKA); and (2) weight or BMI change was deemed to be associated with THA or TKA. The excluded studies: (1) included weight or BMI interventions; and (2) reported on unicompartmental, partial, or revision arthroplasty or joint arthroscopy. Meta-analyses for weight change, BMI change, and proportion of patients achieving clinically significant change were performed using random-effects models. Factors associated with clinically significant change were systematically reported. A total of 60,837 patients from 39 studies were included.

Results: No significant differences existed between preoperative and postoperative weights (P = 1.0; P = 0.28) or BMIs (P = 1.0; P = 1.0) after THA or TKA, respectively. Overall, 66% of THA patients (P < 0.01) and 65% of TKA patients (P < 0.01) did not experience clinically significant weight change.

Conclusions: Among a TJA cohort, two-thirds of the patients maintained their preoperative body weight or BMI after surgery. With these results, orthopaedic surgeons can better manage patient expectations of TJA.