There are a few reports in the literature that deal with the results of total knee replacement arthroplasty in young rheumatoid arthritis patients. This study was undertaken to evaluate the results of total knee replacement arthroplasty in rheumatoid arthritis patients under the age of 45 years.

Between 1989 and 1993, 43 total knee replacement arthroplasties were performed in 26 adults with rheumatoid arthritis. The age at operation ranged from 23 to 45 years old (average 36.3 years). Of these, four patients (six knees) were lost to follow-up, so 37 knees in 22 patients were available for the follow-up evaluation at a mean 7.8 years (5-8.9).

Preoperative flexion contracture was found in 33 knees (89.2%) among 37 knees and it was corrected by operation from 33.1 to 2.6 postoperatively. So the range of motion also improved by an average of 25.6 compare with preoperative state. At the time of final follow-up, six patients were free of pain and 15 patients had mild pain during weight-bearing state, but one patient, with loosening evidence complained of occasional moderate pain. The American Knee Society knee score was improved from a mean of 37.9 points preoperatively to 84.9 points postoperatively. There were 22 excellent, 14 good and one poor (loosening case) results. All patients were able to walk after the operation from 11 non-ambulators and 11 ambulators, assisted with a walking device in preoperative state. The average functional score also improved from 11.9 points to 86.8 points. Radiographic evaluation revealed a radiolucency rate of 43.2%, and revealed radiolucent line adjacent to 3 femoral and 15 tibial components. Almost all of the patients (91%) were satisfied with the result of operation, subjectively. Only one patient had a revision because of subsidency and loosening of a tibial prosthesis.

We considered that total knee replacement arthroplasty for patients with rheumatoid arthritis and was less than 45 years old provided satisfactory and effective results.