Prior Bariatric Surgery Is Not Associated with Increased Risk Following Lower Limb Arthroplasty: A Propensity-Matched Cohort Study

Abstract Introduction: Severe obesity increases adverse outcome risks following lower limb arthroplasty. Bariatric surgery provides sustained weight loss and metabolic improvement, but its role before arthroplasty remains unclear. This study compared arthroplasty outcomes after bariatric surgery with matched controls. Methods In this retrospective propensity-matched cohort study, patients undergoing bariatric surgery before total hip or knee arthroplasty were compared with controls matched for body mass index (BMI), age, sex, American Society of Anesthesiologists classification, Charlson Comorbidity Index, and diabetes at arthroplasty. Outcomes included operative time, composite adverse events, complications, readmission, return to the operating room, and mortality. Results Ninety patients with prior bariatric surgery (36 hip arthroplasties, 54 knee arthroplasties) were compared with 180 controls. Groups had similar BMI (39.3 ± 7.0 vs 38.8 ± 6.0 kg/m²) and associated medical problems. Bariatric surgery resulted in pre-arthroplasty weight loss (23.6 ± 12.9% of total body weight) and reduced diabetes prevalence (23.3% to 6.7%). Operative time did not differ (104 vs 96.5 minutes, p = 0.179). Composite adverse events occurred in 18.9% of both groups (p = 0.999). Major complications, readmission, return to the operating room, and mortality were comparable (all p > 0.05). Bariatric surgery was not independently associated with adverse outcomes; higher BMI predicted increased complications. Conclusion With BMI and associated medical problems matched, prior bariatric surgery was not associated with worse arthroplasty outcomes. Current BMI appears to be the primary determinant of postoperative risk. Bariatric surgery should be considered as a risk-mitigating strategy before lower limb arthroplasty.