Does the direct anterior learning curve persist after fellowship training? A single-center comparative cohort study

Abstract Introduction : The direct-anterior-approach (DAA) for total hip arthroplasty (THA) has significant benefits but has historically been associated with a steep learning curve. However, modern training in the approach may eliminate that learning curve. We hypothesize that newly graduated surgeons with specific training in the DAA would show no difference in complication rates compared to senior DAA surgeons. Methods : This retrospective cohort study included 600 primary THAs performed via a DAA from a single institution between November 2019 and February 2025 with a minimum of 90-day follow up. Intra- and post-operative complications were compared between the following two groups: the first 100 cases of each of three junior fellowship-trained arthroplasty surgeons (“Junior”) and the most recent 300 cases of a senior fellowship-trained arthroplasty surgeon (“Senior”). Results: The incidence of operative complications was low and showed no significant difference between groups (Junior − 30 (10.0%) vs Senior − 23 (7.7%), p = 0.39). Subgroup analyses showed no between-group differences for DVT (1.3 vs 0.7%, p = 0.686), PE (0.7 vs 0.3%, p = 1.000), hematoma (0.3 vs 1.0%, p = 0.62), dislocation (1.3 vs 0.3%, p = 0.37), periprosthetic fracture (1.7 vs 1.0%, p = 0.73), neuropraxia (1.3 vs 2.0%, p = 0.75), prosthetic joint infection (1.0 vs 0.3%, p = 0.62), or wound complications (2.3 vs 2.3%, p = 1.00) (Table 2). Medical events were infrequent, with a non-significant trend toward more events in the Senior cohort (Junior − 7 (2.3%) vs Senior − 14 (4.7%), p = 0.181). Operative time was found to be longer among Junior surgeons (92.3 vs 68.5 minutes, p < 0.0001). No difference in patient reported outcome measures (PROMs) were found at 90 day follow up between junior and senior surgeon cohorts. Conclusion : The results of this study suggest that while fellowship-trained DAA surgeons starting practice have longer operative times, there is no difference in overall complication rates or patient-reported functional outcomes when compared to a Senior DAA surgeon. This demonstrates that the historical learning curve surrounding adoption of the DAA may not apply with exposure to the approach during adult-reconstruction fellowship training.