Metacarpophalangeal joint implant arthroplasty with a Silastic spacer.

We evaluated Silastic implant arthroplasty in the metacarpophalangeal joints of rheumatoid patients by a prospective analysis of the cases of twenty-eight patients. One hundred and fifteen such implants were followed for an average of fifty-four months (range, twenty-four to 125 months). The postoperative active motion of the metacarpophalangeal joint averaged 43 degrees, from 13 degrees of extension to 56 degrees of flexion. The average range of active motion of the metacarpophalangeal joint increased 17 degrees over preoperative values. Ulnar drift recurred in forty-nine fingers (43 per cent), and fracture of the spacer occurred in twenty-four joints (21 per cent). The sites of three spacers became infected, and treatment required the amputation of one finger. Preoperative and postoperative key pinch and grip strengths were unchanged. Patient satisfaction was high; twenty patients (71 per cent) experienced significant pain relief, nineteen patients (68 per cent) felt that they had much better hand function, and twenty-three patients (82 per cent) thought that the cosmetic appearance of the hand was improved.