Total hip arthroplasty (THA) requires bone reconstruction in case of severe acetabular injury, with risk of dislocation, especially postoperatively. Dual-mobility cups have proved effective in preventing dislocation in THA revision for instability, but their behavior when cemented in a metal reinforcement has been little studied.
The present study assessed results for a dual-mobility cup cemented in a metal reinforcement, in terms of aseptic loosening and postoperative instability.
Material and methods
A single-center continuous series of 62 patients receiving such an assembly in THA revision was assessed retrospectively at a minimum 5 years’ follow-up. Failure due to aseptic loosening or instability and implant survival at last follow-up were analyzed.
Radiological and clinical analysis was performed at a mean 77 months’ follow-up. Mean Merle–d’Aubigné–Postel score was 14, Harris score 73 and Oxford-12 score 23.9 at last follow-up. Complications comprised 5 cases of loosening and 2 of dislocation. Loosening risk was significantly greater in case of<2mm cement thickness between cup and reinforcement. Eight-year infection-free survival was 91.9%.
The present clinical results were comparable to those in series using the same kind of assembly; the dislocation rate was low, but the rate of aseptic loosening was higher than reported elsewhere. Cement thickness between cup and reinforcement was a determining factor for stability. Cup design may also be relevant to loosening. This technique seemed to be a good option in THA revision with severe bone loss.
Level of evidence
IV, retrospective study.Le texte complet de cet article est disponible en PDF.
Keywords : Revision, THA, Reinforcement, Dual-mobility, Cemented, Aseptic loosening, Instability