# Outcomes of total hip arthroplasty in obese patients with and without preoperative weight loss: A systematic review and meta‐analysis

## TL;DR

This study finds that preoperative weight loss in obese patients does not improve outcomes after total hip arthroplasty compared to those who do not lose weight.

## Contribution

The study is the first meta-analysis to systematically evaluate the impact of preoperative weight loss on THA outcomes in obese patients.

## Key findings

- Preoperative weight loss does not reduce postoperative complication rates in obese THA patients.
- There is no significant difference in infection, reoperation, or revision rates between weight loss and non-weight loss groups.
- Routine weight loss requirements for obese THA patients may not be justified based on these findings.

## Abstract

Obesity is often considered a relative contraindication to total hip arthroplasty (THA) due to presumed increased perioperative and postoperative risk. Consequently, obese patients are often advised to lose weight prior to THA. However, the effect of preoperative weight loss on THA outcomes remains uncertain. This meta‐analysis compared outcomes in obese patients who lost weight preoperatively with those who did not.

This review was performed according to Preferred Reporting Items for Systematic Reviews and Meta‐analysis (PRISMA) guidelines and registered in PROSPERO. Medline and Embase were searched on 1 February 2025. Two reviewers independently screened and extracted data from studies comparing outcomes in obese patients undergoing primary THA with and without preoperative weight loss. Outcomes of interest (complications, infections, readmissions, reoperations and revisions) were pooled via Freeman–Tukey double arcsine transformations using inverse‐variance weighting within a random‐effects model framework to calculate estimates of proportions and their corresponding p value.

Of 2896 identified references, 8 studies were included, resulting in 4848 patients with preoperative weight loss and 78,860 patients without. Interventions included bariatric surgery (1 study), non‐surgical measures (2) and unspecified methods (5). There were no significant differences in outcomes between groups, with regards to complication rates in the short‐term (weight loss: 14% vs. control: 8%, p = 0.163) or mid‐term (5% vs. 8%, p = 0.568), prosthetic joint infection rates in the short‐term (5% vs. 4%, p = 0.458) or mid‐term (6% vs. 4%, p = 0.289), reoperation rates in the short‐term (2% vs. 1%, p = 0.840) or mid‐term (7% vs. 4%, p = 0.139), revision rates in the short‐term (1% vs. 1%, p = 0.401) or mid‐term (3% in both groups, p = 0.906) and readmission rates (5% vs. 4%, p = 0.077).

Preoperative weight loss in obese patients undergoing THA does not reduce the risk of postoperative complications, infections, readmissions, reoperations or revisions compared with obese patients who did not lose weight preoperatively. These findings question routine weight loss requirements and underscore the need for individualized risk assessment over body mass index alone.

Level IV.