Radiographic and Clinical Outcomes of Dual Mobility Total Hip Arthroplasty: A Retrospective Comparative Study from a
Monica Georgiana Roman1,2, Alexandru Lisias Dimitriu1,2, Elisa Georgiana Popescu1,2
1Department 14 Orthopaedics-Intensive Care, "Carol Davila" University of Medicine and Pharmacy, 050474 Bucharest, Romania.
Abstract:
Background: Dual mobility (DM) total hip arthroplasty (THA) was introduced to reduce postoperative instability, one of the most frequent causes of revision after hip replacement. Its use has progressively expanded beyond revision surgery to selected high-risk primary cases; however, comparative data integrating both clinical and radiographic outcomes from real-world tertiary centers remain limited. Methods: A retrospective comparative study was conducted including 78 patients who underwent THA with a DM acetabular component between January 2019 and December 2024, and 78 matched controls who received conventional fixed-bearing THA during the same period. Matching criteria were age, sex, and procedure type (primary versus revision). Clinical outcomes were assessed using the Harris Hip Score (HHS) and visual analogue scale (VAS) for pain. Radiographic evaluation focused on component positioning, radiolucent lines, and signs of loosening. Complications and revision rates were compared between groups. Results: The mean age was 71 ± 9 years, and 62% of patients were female. Mean follow-up was 38 months. HHS improved from 54 ± 10 preoperatively to 89 ± 8 postoperatively in the DM group (p < 0.001), with similar final functional outcomes in the conventional THA group (90 ± 9, p = 0.48), and comparable improvement between groups (p = 0.62). Radiographic parameters demonstrated stable fixation and appropriate component positioning in both groups, with no significant intergroup differences. The dislocation rate was numerically lower in the DM group (1.3% vs. 5.1%), although this difference did not reach statistical significance (p = 0.37). No cases of intraprosthetic dislocation occurred. Overall implant survival free from revision at five years was 96.5% for DM and 94.7% for conventional THA (p = 0.47). Conclusions: DM THA achieved excellent clinical and radiographic outcomes, with a numerically lower dislocation rate than conventional THA. Mid-term implant survivorship was comparable between groups, supporting DM as a reliable option for improving stability in appropriately selected patients.
