Total prosthesis on a rheumatoid knee

: Results of 81 total knee replacements in 67 patients with rheumatoid arthritis were studied. Mean follow-up was three years. Pain was the main reason for knee replacement surgery; knee mobility was well preserved prior to surgery. Failure occurred in four patients, as the result of infection, due in three instances to skin necrosis. Arthrodesis of the knee proved necessary in these patients. The fourth patient developed delayed hematogenous infection which was treated by a change of prosthesis. At follow-up, 82% of patients reported no pain and 18% moderate pain. Mean passive flexion was 113 degrees +/- 17 degrees. HSS score was 83.6 +/- 1.3 and all the patients except for the four with prosthesis failure stated that they were satisfied on very satisfied. Mechanical results were satisfactory, with a mean mechanical femur-tibial angle of 180.4 degrees. A circling line was visible at follow-up in 40% of operated knees but was partial in every case. No reoperations for prosthesis loosening were required. These data show that total knee replacement is the only reliable and radical treatment of rheumatoid arthritis of the knee and should be performed as soon as fixed flessum or axial deviation develops.