Swanson metacarpophalangeal joint arthroplasty in patients with rheumatoid arthritis.

Between 1981 and 1991, 348 Swanson metacarpophalangeal replacements were implanted in patients with rheumatoid arthritis. There were 64 female and seven male patients. Both hands were reconstructed in 18 patients. Clinically, 170 implants were available for an average of 5.2 years (range, 2-10 years) followup. Severe synovitis was seen in 7% of metacarpophalangeal joints, moderate synovitis in 25%, slight synovitis in 17%, and synovitis was not present in 51%. Pain was found to be severe in 4% of the joints, moderate in 3%, slight in 39%, and not present in 54% of the joints. The average preoperative active arc of motion was 38 degrees, and the average postoperative arc of motion was 27 degrees. Eleven of 12 fractures found were revised. There were no infections. Functionally, of 58 patients assessed, 58 (100%) reported the ability to feed themselves, 55 (94%) to button clothes, and 54 (93%) to write. Quality radiographs were available in 144 joints. Eighty-four percent of implants showed sclerosis of bone and 8% showed resorption adjacent to the implant. Survivorship analysis revealed a 94% success rate at 5 years, 93% at 7 years, and 90% at 10 years using the end point of revision surgery.