Frank Stinchfield Award: Does Bariatric Surgery Prior to Primary Total Hip Arthroplasty Really Improve Outcomes?

Background: Optimal management of morbid obesity before total hip arthroplasty (THA) remains debated. Recently, bariatric procedures have become more common with advancements in surgical techniques. We hypothesized that bariatric surgery prior to primary THA would mitigate acute postoperative complications and improve implant survivorship. Methods: A retrospective review from 1995 to 2020 identified 88 primary THA procedures in 71 unique patients who previously underwent bariatric surgery (73% Roux-en-Y). This cohort was matched 1:1:1 for age, gender, surgical year, American Society of Anesthesiologists score, and Charlson Comorbidity Index to cohorts of patients with body mass index (BMI) <40 kg/m² and BMI ≥40 kg/m². Revisions, reoperations, and acute complications were compared. Subgroup analysis then evaluated historical (pre-2012) relative to contemporary (2012 and after) bariatric procedures. Results: Revision rates for bariatric patients were higher relative to controls with low (hazard ratio [HR] 19, P <.01) and high BMI (HR 8, P <.01). Reoperation rates showed a similar increase for bariatric patients when compared to low (HR 9, P <.01) and high BMI (HR 4, P =.01) patients. Moreover, bariatric patients had an increased dislocation risk compared to the low (HR 7, P =.03) and high BMI (HR 17, P <.01) patients. Contemporary bariatric techniques had similar complications, revisions, and reoperations relative to historical procedures. Conclusion: Morbidly obese patients undergoing THA have increased risks of certain complications, but it is unclear if bariatric surgery improves this risk. This study found that patients undergoing bariatric surgery have worse implant survivorship and higher dislocation rates compared to patients with naturally low and high BMIs. Further investigation into the post-bariatric metabolic state is warranted. Level of Evidence: Prognostic Level IV.