[Modular-physiological wrist arthroplasty in rheumatoid arthritis].

Silicone wrist arthroplasty has dominated reconstructive surgery of the rheumatoid wrist for a long time. The declining success rates of Swanson wrist arthroplasty has encouraged the development of new wrist devices. Modular physiological total wrist arthroplasty represents a new wrist prosthesis generation with anatomical reconstruction of carpal height and wrist pivot. This increases the efficiency of wrist and finger tendons. Modular physiological total wrist arthroplasty was developed in 1992 and has been in clinical application since 1993. A total of 46 total wrist arthroplasties in 39 patients were carried out between 1993 and 1999. All patients suffered from rheumatoid arthritis. The mean follow-up period was 4.6 years. The postoperative total wrist score averaged 77.3 points, representing 78% good and excellent scores. Patient satisfaction and pain relief were achieved in 86% of cases. The range of motion at last follow-up averaged 56 degrees of the combined extension and flexion and 27 degrees for combined ulnar and radial deviation were maintained. The radiographic analysis of MPH total wrist arthroplasty demonstrated a secure reconstruction of carpal height and restoration of joint pivot. Failures occurred in seven wrist arthroplasties. Malalignement of the carpal and radial component and soft-tissue dysbalance were the reasons for recurrent dislocation in four cases. Three wrists were fused and one exchange arthroplasty using a constrained revision prosthesis was performed. The remaining three revision cases were caused by one deep infection and two failures of the carpal implant.