Comparison between dual mobility and conventional total hip arthroplasty in East Asian, using nationwide database

Introduction: Dual mobility (DM) design increases the effective femoral head size and improve stability with increased jump distance and without impingement. The purpose of this study was to compare clinical outcomes and revision rate between conventional total hip arthroplasty (THA) and DM. Materials and methods: Using the Korean National Health Insurance Service database, patients ≥ 19 years who underwent primary THA between 2015 and 2019 (n = 47,119) were identified. Cumulative incidences of dislocation, periprosthetic joint infection (PJI), periprosthetic fracture were evaluated. Multivariable Cox proportional hazard regression ratios (HRs) were used to compare cup revision, stem revision and any revision within 6 years follow-up. Results: In adjusted analyses, DM showed a lower risk of dislocation (aHR = 0.57, 95% CI = 0.42–0.77) and higher risk of PJI (aHR = 1.46, 95% CI = 1.04–2.05), compared to conventional THA within 1 year, as well as within 30 days, 90 days. There were no significant differences in risk of cup revision (aHR = 0.66, 95% CI = 0.39 to 1.11), stem revision (aHR = 1.38, 95% CI = 0.95 to 2.01) and any revision (aHR = 0.99, 95% CI = 0.76 to 1.30). Conclusions: We found a lower risk of dislocation and a higher risk of PJI for DM compared with conventional THA. And there was no difference in the overall revision rate between both groups. Our findings suggested that we can recommend DM when used, especially in patients with high risk of dislocation.