This study reviewed the long-term results of metacarpophalangeal joint arthroplasty in patients with rheumatoid arthritis. 208 arthroplasties in 52 hands of 36 patients were evaluated at an average follow-up of 14 years (range, 6-21 years). The mean arc of motion improved from 30 degrees pre-operatively to 46 degrees immediately post-operatively and decreased to 36 degrees at final follow-up. The mean extension deficit of the MCP joints improved from 57 degrees pre-operatively to 11 degrees immediately post-operatively, to 23 degrees at final follow-up. Mean digital flexion changed from 87 degrees pre-operatively to 57 degrees immediately post-operatively and remained at 59 degrees at final follow-up. The mean ulnar drift improved from 26 degrees preoperatively to less than 5 degrees immediately after surgery, and subsequently returned to an average of 16 degrees at final follow-up. 63% of the implants were broken at final follow-up and 22% were deformed. Implant fractures were associated with increased ulnar drift at final follow up. The Michigan Hand Outcomes questionnaire averaged 48 of 100 points at final follow- up. Only 38% of the hands expressed satisfaction with its function and only 27% were pain free at final follow-up. Greater degrees of ulnar drift were associated with decreased patients satisfaction and a decreased score for the cosmetic appearance. The final metacarpal length was 90% of the length of the metacarpal immediately postoperatively and the proximal phalanx was 94% of the length of the phalanx immediately post operatively. The proximal phalanx, however, was more likely to exhibit resorption than were the metacarpals. 71% exhibited sclerosis adjacent to the implants of unknown significance. Similar fracture rates were noted for the Swanson and Sutter implants.
This study provides valuable information on the long-term outcome of MCP joint arthroplasties in rheumatoid arthritis using silicone. When counseling patients, they can be informed that at an average of 14 years following operative intervention, approximately 65% of the implants are broken and 20% are deformed. In addition only 30% of the patients are satisfied with the function of their hands and only 27% are pain free. However, the extension deficit may still be improved over pre-operative values and total arc of motion gains will persist. Limitations of this study include its retrospective nature and the fact that no attempts were made to correlate wrist alignment (and surgical interventions to stabilize the wrist) with the overall outcome.
J of Bone and Joint Surgery