Modular Physiological Wrist Arthroplasty in Rheumatoid Arthritis

Background: Especially when multiple joints are affected by rheumatoid arthritis total wrist arthroplasty (total wrist arthroplasty) provides better function and higher patient satisfaction than fusion. The midterm results of a new total wrist prosthesis with cementless fixation are reported. Materials and Methods: The modular physiological total wrist arthroplasty represents a new wrist prosthesis generation with anatomic reconstruction of carpal height and wrist pivot. The physiological total wrist arthroplasty was developed in 1992 and has been in clinical application since 1993. 26 total wrist arthroplasty with the MPH prosthesis were implanted for the treatment of severe rheumatoid arthritis between 2003 and now. The mean follow-up period was 3.1 years (range: 1 to 5.2 years). Each wrist was rated on the 100-point scale of Clayton based on wrist balance, range of motion, pain relief and extensor strength. Results: The postoperative total wrist score averaged 86.4 points, representing 92% of good and excellent score results. Three patients were judged fair. A poor result was obtained in a septic case. Patient satisfaction and pain relief were achieved in 92%. Total range of motion (flexion/extension) averaged 66 degrees and for combined ulnar and radial deviation 27 degrees were maintained. Failures occurred in the first series exclusively. Malalignment of the carpal and radial component and soft-tissue dysbalance were the reasons for recurrent subluxation in 1 case and traumatic luxation in I case (2x). Conclusion: The introduction of the MPH prosthesis successfully solved the problems of the primary design and the mid-term clinical results have substantially improved. The restoration of wrist mechanics with reconstruction of carpal height and wrist pivot, increasing the efficiency of wrist and finger tendons are the main benefits of total wrist arthroplasty.