The purpose of this study was to compare the posterior approach (PA) with the direct anterior approach (DAA) among obese and nonobese total hip arthroplasty patients to determine if obese DAA patients have a higher risk of infection or wound complications compared with obese PA patients.
We retrospectively evaluated 4651 primary total hip cases performed via anterior approach or PA between 2009 and 2015. Patients were divided into 4 study groups based on approach and body mass index (BMI): (1) DAA <35 kg/m2, (2) DAA ≥35 kg/m2, (3) PA <35 kg/m2, and (4) PA ≥35 kg/m2. Infection rates and wound complications were compared.
The rate of deep infection in groups 1 and 3 (nonobese anterior vs posterior) was 0.28% and 0.36%, respectively (P = .783); and in groups 2 and 4 (obese anterior vs posterior) was 2.35% and 2.7%, respectively (P = .80). The rate of wound complications between groups 1 and 3 (nonobese) was 1.0% and 0.3%, respectively (P = .005). Between groups 2 and 4 (obese), the rates of complications were 1.7% and 1.4%, respectively (P = 1.0). There was no difference in reoperation rates for wounds between groups 1 and 3 or between groups 2 and 4 (P = .217, P = .449).
In the largest available series, there was no difference in deep infection rates between the 2 approaches. In the subset of obese patients with BMI ≥35 kg/m2, there was no increased risk of deep infection or wound complications in DAA patients compared with PA patients. However, anterior hip cases experienced higher rates of superficial wound complications compared with posterior cases across all BMIs.