Silicone rubber implant arthroplasty of the metacarpophalangeal joint in rheumatoid arthritis: a follow-up study of 32 patients.

A retrospective analysis of silicone rubber implant arthroplasty of the metacarpophalangeal joint in 32 patients with rheumatoid arthritis is reported. One hundred seven implants were followed in 37 hands for an average of 44 1/2 (12 to 120) months. Active motion of the metacarpophalangeal joint averaged 34 degrees, with a mean extension deficit of 7 degrees and a mean flexion 41 degrees. Ulnar deviation recurred to more than 10 degrees in 33 of 107 fingers (31%). Fracture of the spacer was confirmed in four joints (4%). One fracture of the proximal phalanx and one of the metacarpal head had occurred. Bone resorption around the stem or a hinge and migration of the implant were found in 26 (24%) fingers. Patient satisfaction was high; 27 patients experienced significant pain relief, the functioning of 31 hands (84%) was improved, and 28 patients (32 hands) thought that the cosmetic appearance of the hand was improved.