Dislocations Following Total Hip Arthroplasty via Direct Anterior Approach: A Retrospective Analysis of 2933 Cases with One-Year Follow-Up

The direct anterior approach (DAA) for total hip arthroplasty (THA) has gained increasing popularity; however, the incidence, causes and outcomes of dislocations following THA are rarely studied. This study aims to evaluate the incidence, causes, and outcomes of dislocations following DAA THA. This retrospective study included 2933 patients who underwent DAA THA for osteoarthritis between 2014 and 2019, with a one-year follow-up. Data were collected on dislocation rate, directions, timing, associated risk factors, and revision surgeries. Hip function outcomes were assessed using the Oxford Hip Score (OHS), comparing patients with and without dislocations. The dislocation rate was 0.7% (n=21), with 81% of dislocations occurring in the anterior direction and 86% occurring within the first postoperative month. Dislocations were most commonly associated with sitting or rising from a seated position. Patients with dislocations had a higher mean Body Mass Index (29.6 vs 27.0 kg/m², p=0.007). Five patients (24%) required revision surgery. At one-year follow-up, no significant differences in OHS were observed between patients with and without dislocations. Dislocation after DAA THA are rare, with the majority being anterior. Dislocations occur in different positions, but mostly in a seated position, suggesting that specific postoperative precautions may be unnecessary. Despite these dislocations, patients generally experience comparable hip function outcomes at one-year follow-up.