Long-term outcome of Swanson prosthesis management of the rheumatic wrist joint

Abstract

Silicone-wrist arthroplasty has dominated reconstructive surgery of the rheumatoid wrist for a long time. Silicone interposition wrist arthroplasty yielded good clinical results in short and midterm studies. The durability and longevity of the prosthesis however is limited and progressive X-ray deterioration and silicone synovialitis are the main shortcomings. We present the ten-year follow-up results of 102 rheumatoid wrists operated between 1984 and 1992. 72 patients with 82 wrist arthroplasties were clinically and radiologically examined. The mean age at operation was 56.9 years. The average onset of R.A. was 16.1 years. Each wrist was rated on a 100-point scale, with points based on wrist balance, range of motion, pain relief and extensor strength. The postoperative Clayton score averaged 69.4 points. Including revision cases, 51% of the Swanson implants were rated good or excellent, 16% fair, and 33% were judged poor because of pain or prosthesis breakage. Patient satisfaction and pain relief were achieved in 68.2%. Active motion with unrevised implants was 21 degrees extension and 31 degrees flexion. We noticed a moderate increase (7 degrees) for ulnar-radial deviation. There was a progressive deterioration in the radiographic appearance. Implant fracture occurred in 31% of the patients. Subsidence of the implant and significant reduction of carpal height was noticed in 82.5% of the prosthesis. Revision procedures were performed in eleven cases. We conclude that the clinical and radiological results of Swanson silicone interposition arthroplasty will deteriorate with the passage of time. Beyond the potential deleterious effects of silicone, long-term radiological complications such as implant fracture, subsidence and carpal collapse are the main disadvantages of Swanson arthroplasty of the wrist. We therefore currently recommend the MPH-total wrist design in patients with rheumatoid arthritis.