TEN-YEAR FOLLOW-UP OF SILICONE ARTHROPLASTY OF THE METACARPOPHALANGEAL JOINTS IN RHEUMATOID HANDS

In resection arthroplasty of destroyed metacarpophalangeal joints stabilisation with a silicone spacer is regarded as the gold standard. In 28 patients with rheumatoid arthritis (34 hands) 102 arthroplasties of the metacarpophalangeal joint were assessed a median of 10 years postoperatively (range 8.7-12.5). All patients reported pronounced subjective relief of pain, and in three quarters function of the hand had improved. The median active range of movement decreased from 40° (range 10°-90°) preoperatively to 35° (range 5°-85°) postoperatively. Ulnar deviation was corrected from a median of 35° (range 0°-60°) preoperatively to 10° (range 0°-40°) postoperatively. The extension deficit was improved from a median of 35° (range 10°-80°) before surgery to a median of 10° (range 0°-30°) at follow up. Grip strength remained unchanged. Radiological examination showed surrounding osteolysis in 89% of the implants and 28% had broken. The well-known discrepancy between fair clinical and good subjective results with distinct radiological findings such as osteolysis was therefore confirmed. Material fatigue and sharp bony edges that result from osteolysis may be the cause of the relatively common implant fractures and ulnar deviation in this long-term follow-up.