Bariatric Surgery Prior to Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis of Postoperative Outcomes.

BACKGROUND

Obesity is a major risk factor for perioperative complications following total joint arthroplasty (TJA). Bariatric surgery has been proposed to reduce these risks, but previous studies report inconsistent findings. The effect of bariatric surgery before arthroplasty remains uncertain. We sought to determine whether prior bariatric surgery, compared with no bariatric surgery, is associated with reduced perioperative medical complications, reduced surgical complications and differences in revision rates.

METHODS

A systematic literature search was conducted in the major databases since their inception up to June 2025 to identify studies comparing postoperative outcomes in patients undergoing total hip or knee arthroplasty with or without prior bariatric surgery. Random effects meta-analysis was used to pool risk ratios across studies.

RESULTS

Thirty studies comprising over 6.2 million patients met inclusion criteria. Bariatric surgery prior to arthroplasty was associated with lower risk of several systemic complications, including venous thromboembolism (hip RR 0.72, 95% CI 0.54-0.94; knee RR 0.70, 95% CI 0.51-0.94), sepsis (knee RR 0.51, 95% CI 0.39-0.65) and stroke (knee RR 0.58, 95% CI 0.41-0.81). These benefits were most pronounced in hip arthroplasty, where lower rates of periprosthetic joint infection (RR 0.71, 95% CI 0.55-0.91) and mechanical loosening (RR 0.72, 95% CI 0.57-0.91) were also observed. Conversely, knee arthroplasty demonstrated higher risks of revision (RR 1.28, 95% CI 1.04-1.57) and dislocation (RR 1.55, 95% CI 1.03-2.31), without significant differences in wound complications or mechanical failure.

CONCLUSIONS

Bariatric surgery prior to total joint arthroplasty is associated with meaningful reductions in medical complications, but these benefits do not consistently extend to surgical endpoints. An increased revision risk in knee arthroplasty highlights the need for individualised preoperative optimisation, nutritional assessment and timing considerations to balance systemic and mechanical risks.

TRIAL REGISTRATION: PROSPERO: CRD420251105136.