Metacarpophalangeal joint arthroplasty in rheumatoid arthritis. A long-term assessment.

BACKGROUND: The long-term results of silicone metacarpophalangeal arthroplasty in patients with rheumatoid arthritis are uncertain. The purpose of this investigation was to evaluate the subjective, objective, and radiographic outcomes at the time of long-term follow-up.
METHODS: Patients with rheumatoid arthritis who underwent simultaneous silicone metacarpophalangeal joint arthroplasties of all four fingers by one surgeon were eligible for inclusion in the study. The results of a total of 208 arthroplasties in fifty-two hands of thirty-six patients were evaluated at an average of fourteen years postoperatively. Active metacarpophalangeal joint motion, ulnar drift, and radiographs were assessed. The radiographs were reviewed for changes in bone length, erosions, and implant fractures. The Michigan Hand Outcomes Questionnaire (MHQ) was administered to the patients.
RESULTS: The mean arc of motion of the metacarpophalangeal joints improved from 30 degrees preoperatively to 46 degrees immediately after the surgery but decreased to 36 degrees at the time of final follow-up. The mean extension deficit of the metacarpophalangeal joints improved from 57 degrees preoperatively to 11 degrees immediately after the surgery but worsened to 23 degrees at the time of final follow-up. The mean ulnar drift improved from 26 degrees preoperatively to <5 degrees in the immediate postoperative period and then recurred to an average of 16 degrees at the time of final follow-up. Implant fractures were associated with increased ulnar drift (p < 0.001). Bone reaction adjacent to the implant was demonstrated by bone-shortening in most patients and by erosions in 29% of the patients. One hundred and thirty implants (63%) were broken and forty-five (22%) more were deformed at the time of final follow-up. The MHQ score averaged 48 of 100 points. The patients expressed satisfaction with the function of only 38% of the hands, and only 27% of the hands were pain-free at the time of final follow-up. A greater degree of ulnar drift was associated with decreased patient satisfaction and a decreased score for the cosmetic appearance (p </= 0.01).
CONCLUSIONS: The outcome after silicone metacarpophalangeal joint arthroplasty in patients with rheumatoid arthritis worsens with long-term follow-up. Given these findings, the indications for and long-term expectations of silicone metacarpophalangeal arthroplasty must be carefully examined in light of the improvements in the medical management of rheumatoid disease.