Cemented total hip arthroplasty in rheumatoid arthritis. A systematic review of the literature.

Background: Cemented total hip arthroplasty (THA) in rheumatoid arthritis (RA) is allegedly associated with increased rates of infection, dislocation and aseptic loosening of cup and stem. Method: Systematic review of the literature on clinical and radiological results of cemented THA in RA. Results: Twenty-one case series and eight reports on four implant registries were included. The quality of most studies was judged to be poor. The reported rates of infection and dislocation in the case series were conflicting with a risk of bias due to under-registration. The registries proved unsuitable for providing reliable data on the incidence of these two complications. Increased rates of aseptic loosening were reported in 10 out of 20 case series on the cup and in six out of 19 on the stem. Nearly all of these were based on series implanted before 1980. None of the registries reported a significantly increased risk of aseptic loosening of cup or stem. Conclusions: Considering the relatively frequent reports of increased infection rates in combination with the potential under-registration of complications, RA patients have to be considered to have a mild increased risk of postoperative infection. Case series and registries cannot answer the question of whether RA is a risk factor for dislocation as multivariate analysis is required. Increased rates of cup and stem failure due to aseptic loosening in RA patients are found in older but not in more recent studies.