Similar Superior Patient-Reported Outcome Measures for Anterior and Posterolateral Approaches After Total Hip Arthroplasty

Background Patient-reported outcome measures (PROMs) are used to evaluate the outcome of total hip arthroplasty (THA). We determined the effect of surgical approach on PROMs after primary THA. Methods All primary THAs, with registered preoperative and 3 months postoperative PROMs were selected from the Dutch Arthroplasty Register. Based on surgical approach, 4 groups were discerned: (direct) anterior, anterolateral, direct lateral, and posterolateral approaches. The following PROMs were recorded: Hip disability and Osteoarthritis Outcome Score Physical function Short form (HOOS-PS); Oxford Hip Score; EQ-5D index score; EQ-5D thermometer; and Numeric Rating Scale measuring pain, both active and in rest. The difference between preoperative and postoperative scores was calculated (delta-PROM) and used as primary outcome measure. Multivariable linear regression analysis was performed for comparisons. Cohen's d was calculated as measure of effect size. Results All examined 4 approaches resulted in a significant increase of PROMs after primary THA in the Netherlands (n = 12,274). The anterior and posterolateral approaches were associated with significantly more improvement in HOOS-PS scores compared with the anterolateral and direct lateral approaches. Furthermore, the posterolateral and anterior approaches showed greater improvement on Numeric Rating Scale pain scores compared with the anterolateral approach. No relevant differences in delta-PROM were seen between the anterior and posterolateral surgical approaches. Conclusion Anterior and posterolateral surgical approaches showed more improvement in self-reported physical functioning (HOOS-PS) compared with anterolateral and direct lateral approaches in patients receiving a primary THA. However, clinical differences were only small.