[Survival of the cementless Bousquet dual mobility cup: Minimum 15-year follow-up of 437 total hip arthroplasties].

PURPOSE OF THE STUDY: The purpose of this study was to evaluate the long-term results of a retrospective series of primary arthroplasty with a cementless dual mobility socket and a cemented Charnley type femoral component.

MATERIAL AND METHODS: This study included 437 hip replacements performed between 1984 and 1990, in 388 patients. The Bousquet's acetabular component, an original concept of cementless dual mobility socket has been used, associated with a cemented Charnley type femoral component. A clinical and radiologic analysis was done.

RESULTS: The outcome is known for 345 hips (79%): 164 alive without revision at a mean of 16,5 years follow-up, 137 died without revision and 44 failures. Ninety-two (21%) were lost at follow-up. According to Kaplan-Meier analysis, the 5-year survival rate, was 84,4%+/-4,5 with revision for any reason (infection, dislocation, osteolysis...) for end point. Revision, for aseptic loosening of femoral or acetabular component, was performed in 30 hips (6,8%). Five dislocations occurred and were revised: two early related to technical errors and three after 10 years or more of follow-up. The young age of the patients at the time of the index surgery was correlated with higher rate of aseptic loosening.

DISCUSSION: The prevalence of revision for dislocation is very low in our series. This concept does not avoid wear, osteolysis and aseptic loosening, especially in young active patients but the long-term stability is confirmed. We recommend this type of prosthesis for patients over 70 years and for younger patients with high risk of dislocation Q.