Stratified Comparison of Short-Term Perioperative Outcomes in Direct Anterior Versus Posterolateral Primary Total Hip Arthroplasty: A Retrospective Review.

Abstract

Background: It is unclear what influence patient sex and body mass index (BMI) have on perioperative outcomes following total hip arthroplasty (THA), especially regarding anterior versus posterolateral approaches. Purpose/Study Questions: We sought to compare perioperative outcomes of primary THA via direct anterior (DAA) versus posterolateral (PLA) approaches, stratified by patient sex and BMI. Methods: A retrospective review at a single institution identified 8258 patients 18 to 80 years old who underwent primary THA via DAA or PLA for osteoarthritis between February 2019 and April 2022. Patients were stratified by sex and BMI (<30 or 30-40). We compared operative times, lengths of stay (LOS), opioid consumption and prescribing patterns, and achievement of Hip Injury and Osteoarthritis Outcome Score for Joint Replacement (HOOS JR) minimum clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) across the cohorts. Results: Median operative time was 6 to 11 minutes longer for DAA than for PLA. Median LOS was shorter for DAA, with the largest difference observed in women with BMI <30 (19-hour difference) and BMI 30 to 40 (20-hour difference). In-hospital milligram morphine equivalents consumed were lower for DAA in men with BMI <30 (45 vs 53), women with BMI <30 (45 vs 53), and women with BMI 30-40 (60 vs 75). There was no difference observed in HOOS JR MCID, SCB, or PASS achievement scores at 1 year for any cohort. Conclusion: This retrospective study found longer operative times for DAA than PLA and shorter LOS in women undergoing DAA than those undergoing PLA. There were minimal clinical differences in in-hospital opioid consumption, 90-day opioid prescription patterns, and patient-reported outcome measures. These findings suggest that patient sex and BMI may have implications on case scheduling and discharge planning for primary THA. Further study is warranted.