The dual mobility socket concept: experience with 668 cases.

Long-term results of a retrospective series of primary arthroplasty with the original cementless dual mobility socket (A) and the midterm results with the second generation (B) are reported. In series A (follow-up 16.5 years) 437 total hip arthroplasties (THA) were included and in series B (follow-up five years) 231 hips. The 15-year survival rate was 84.4 ± 4.5% (revision for any reason as endpoint); 30 hips (6.8%) were revised for aseptic loosening. Five THA were revised for dislocation: two early and three after ten years or more. With the second generation socket neither dislocation nor revision for mechanical reasons were observed. The survival rate was 99.6 ± 0.4% (revision for any reason). The prevalence of revision for dislocation was very low in our series. This concept does not avoid wear and aseptic loosening, especially in young active patients, but the long-term stability has been confirmed. Dual mobility can be recommended for patients over 70 years of age and for younger patients with high risk of dislocation.