Reconstruction of the knee with endoprosthesis in rheumatoid arthritis: a report of 112 consecutive cases operated upon from 1973 through 1977.

In a consecutive series of patients with advanced, seropositive rheumatoid arthritis, 112 severely damaged knees were reconstructed with a stabilizing, total resurfacing prosthesis in 80%, a hemiprosthesis in 13% (3% biocompartmental) and a hinge prosthesis in 7%. Eighty per cent of patients receiving the resurfacing prosthesis were satisfied and, in addition, 8% improved at prospective follow-up examinations one to 5 years postoperatively. The subjective results showed good correspondance with the clinical and roentgenologic assessments. The joints reconstructed with the total resurfacing prosthesis were free from effusion or any inflammatory activity in 96%, stable in 88%, and showed full correction of deformity in 84% while 16% showed a fixed flexion of 10 degrees up to 20 degrees. Walking ability with regard to the need for walking aids was considerably improved. So far, 2% of the knees have had the prosthesis removed and a fusion performed; one per cent because of primary deep infection and the other one per cent because of late deep infection. Four per cent of the cases have shown loosening of the tibial component, necessitating reoperation.