Patient-reported outcome is influenced by surgical approach in total hip replacement: a study of the Swedish Hip Arthroplasty Register including 42,233 patients.

The effects of surgical approach in total hip replacement on health-related quality of life and long-term pain and satisfaction are unknown. From the Swedish Hip Arthroplasty Register, we extracted data on all patients that had received a total hip replacement for osteoarthritis through either the posterior or the direct lateral approach, with complete pre- and one-year post-operative Patient Reported Outcome Measures (PROMs). A total of 42 233 patients met the inclusion criteria and of these 4962 also had complete six-year PROM data. The posterior approach resulted in an increased mean satisfaction score of 15 (sd 19) vs. 18 (sd 22) (p < 0.001) compared with the direct lateral approach. The mean pain score was 13 (sd 17) vs. 15 (sd 19) (p < 0.001) and the proportion of patients with no or minimal pain was 78% vs. 74% (p < 0.001) favouring the posterior approach. The patients in the posterior approach group reported a superior mean EQ-5D index of 0.79 (sd 0.23) vs. 0.77 (sd 0.24) (p < 0.001) and mean EQ score of 76 (sd 20) vs. 75 (sd 20) (p < 0.001). All observed differences between the groups persisted after six years follow-up. Although PROMs after THR in general are very good regardless of surgical approach, the results indicate that some patients operated by the direct lateral approach report an inferior outcome compared with the posterior approach. The large number of procedures and the seemingly sustained differences make it likely these findings are clinically relevant.