Total Knee Replacement in Rheumatoid Arthritis

Total replacement of 24 knees has been carried out in 20 patients with severe rheumatoid arthritis. The indications for operation were pain, stiffness, or instability of the knee. Eighteen knees were replaced by a Walldius prosthesis, and six knees by a Shiers prosthesis. The mean follow-up was three years. One patient with a Walldius prosthesis has been lost to follow-up and two Walldius prostheses were removed because of infection, leaving 17 patients, and the results of 15 Walldius arthroplastics and 6 Shiers arthroplastics for analysis. Flexion greater than 70 degrees was present in 17 arthroplasties (11 WalMius and 6 Shiers), and from the patients' view the operation was worthwhile in 17 arthroplasties (14 Walldius and 3 Shiers). These figures show that 71% of the 24 arthroplasties were satisfactory from an objective and subjective assessment, although functional capacity of the patients has not improved following operation. Extension lag was greater in the Shiers group owing to patellectomy being carried out with this arthroplast. There was a high incidence of early complications, the commonest being infection. Deep infection accounted for 12.5% of the early infection rate of 20.8%. We hope that newly developed prostheses for the knee joint will prove to be more successful than the current hinge prostheses.