Aseptic loosening of implants following hip arthroplasty is a cause of significant patient morbidity. We genotyped 99 revision hip arthroplasty patients and 116 primary hip arthroplasty patients for the C282Y and the H63D mutations, which cause Haemochromatosis. Haemochromatosis is an inherited condition leading to excessive iron absorption and deposition in the body. All patients at the time of their primary hip arthroplasty were diagnosed as having osteoarthritis. We identified 9 of the 99 revision arthroplasty patients as being homozygous for the C282Y mutation. The time to revision in this group was significantly lower (p< 0.005) when compared to the remaining 90 patients in the group (mean 8.7 years vs 14.8 years). Analysis of variables such as patient age and sex and also type of prosthesis, place of surgery and operating surgeon had no confounding influence. We hypothesise that undiagnosed iron overload in the patients homozygous for the C282Y mutation is likely to cause premature failure of their primary hip arthroplasty.

Osteoarthritis of the hip exhibits progressive degeneration of articular cartilage frequently resulting in total hip arthroplasty (THA). Expression of cytokines such as tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL6) is increased in the synovium and articular cartilage of these patients. Furthermore, these cytokines have been shown to have a negative regulatory effect on chondrocyte proliferation and articular cartilage metabolism. We investigated the frequency of a G/C polymorphism at position −174 of the promoter region of the IL-6 gene and a G/A polymorphism at position −308 of the TNF alpha gene, both of which cause increased expression of these cytokines. We observed that the G variant of the IL6 gene was significantly higher in patients who had undergone revision THA compared to controls (P=0.05). It was also elevated in primary THA patients compared to controls. The G/A polymorphism in TNF alpha was not significantly associated with THA; however, this may reflect the lower incidence of this polymorphism in the population. These results suggest that an alteration in cytokine expression produced by the IL6 −174G/C mutation may have a role in the aetiology of osteoarthritis and the outcome of total hip arthroplasty.