Mortality after total knee arthroplasty in patients with osteoarthrosis and rheumatoid arthritis

Total knee arthroplasty (TKA) is a widely used procedure in the treatment of severe destruction of the knee joint because of osteoarthrosis (OA) or rheumatoid arthritis (RA). The aim of this study was to explore whether there is an increased mortality in patients after TKA with the underlying diagnosis OA or RA compared with the general population. We studied a consecutive series of 422 primary TKAs with a hinged Blauth prosthesis in 330 patients (OA: 208 patients, 175 women, 33 men; RA: 122 patients, 109 women, 13 men) with a mean follow-up of 6 years (range 0-20 years). The mean age of the patients at the time of surgery was 70 years (range 29-87 years), being 72 years (range 46-87 years) for OA, and 66 years (range 29-84 years) for RA. Age standardized mortality ratios (SMRs) were calculated for OA and RA. In patients with OA, the SMR was 1.03 (95% CI 0.76-1.37) for women and 1.14 (95% CI 0.68-1.80) for men. SMRs of patients suffering from RA showed a clear shortening of the life span (women: 2.92, 95% CI 2.17-3.85; men: 3.09, 95% CI 1.0-7.19). In spite of the risk of intra- and perioperative complications and further operative procedures necessary because of late complications, the implantation of a knee prosthesis per se does not necessarily significantly reduce the life expectancy in patients with OA. Patients with RA who require the implantation of a total knee prosthesis obviously represent a high-risk group with a high mortality rate.