Introduction: There are conflicting data regarding the safety of the direct anterior approach (DAA) for primary total hip arthroplasty (THA) during the learning process. The aim of this study was to evaluate the intra- and postoperative complication rates of DAA THA performed by supervised trainees compared with senior surgeons.

Material and methods: A retrospective cohort study was conducted using a prospectively maintained arthroplasty database of patients who underwent primary THA via the DAA between 01/08/2013 and 31/12/2022. We compared all cemented and cementless DAA THR using one implant system operated by senior surgeons (n = 6044) and supervised trainees (n = 385) with regard to operative time, intraoperative complications, and re-operation rate. Data were compared using Mann-Whitney-U-testing or t-tests and Pearson's chi-squared test or Fisher's exact test, as appropriate. The Kaplan-Meier method with 95% confidence intervals (CI) was used to determine septic- and aseptic-free implant survival.

Results: After a median follow-up of 3.9 (IQR: 2.4-5.9) years, there was no significantly higher rate of septic- or aseptic-revisions (supervised trainees: 2.6% vs senior surgeons: 1.7%; p = 0.529). There was a significant higher rate of intraoperative complication in the trainee group (supervised trainees: 2.6% vs senior surgeons: 1.3%; p = 0.036). Senior surgeons operated on more complex cases; however, the operative time of the trainees was significantly longer than that of the senior surgeons, 88 (IQR: 78-103) min vs. 61 (IQR: 50-79) min, respectively (p < 0.001). Patient demographics showed no significant differences between the two groups except for BMI, which was significantly higher in the trainee group (p = 0.008).

Conclusion: Although the operating time and intraoperative complication rates are higher for supervised trainees, there is no significantly higher rate of postoperative septic or aseptic revisions. These findings highlight the importance of structured training programs in ensuring patient safety and surgical competence among trainees.