This multi-center study (Cabuenes Hospital and Santa Lucia University Hospital) assessed the results of a retrospective and ongoing series of 135 total hip arthroplasties (THA) in which a latest generation dual-mobility cup was implanted.
A total of 135 THAs performed between 2005 and 2008 were analyzed. Mean follow-up was 32 months. The causes of surgery were: coxarthrosis in 31.8% and hip fracture in 68.1%. Mean age was 82.1 years. All patients were seen at regular follow-up visits for clinical and radiological assessments.
The follow-up lasted over 24 months in 121 THAs (14 patients died). In the most recent follow-up, in May 2011, 119 cups did not show any loosening. Complications were as follows: 2 postoperative dislocations; 4 DVTs; 3 infections; 5 periprosthetic fractures; 2 loosened cups, and one subsided stem. The mean preoperative Harris Hip Score (HHS) was 45, 83; the mean postoperative HHS was 80.03. Only two of the 135 cups analyzed had radiographic modifications without clinical signs. Isolated cup survival at 12 months was 97.03% (87.3-99.2) with a 95% confidence interval; survival at 5 years was 96.7% (85.4-98.8).
In our study, the new dual-mobility cup showed good results for the following indications: primary coxarthrosis and femur neck fractures.
The complication rate in our series was similar to the one reported in other series in the literature, except for dislocation. The latter was considerably less frequent (1.48%) in our series compared to the rates reported by the classical series, especially in patients with neuromuscular or cognitive problems (one third of patients).