Total wrist arthroplasty using the Universal 2 prosthesis.

PURPOSE To report outcomes of 21 total wrist arthroplasties (TWA) using the Universal 2 prosthesis. METHODS Five men and 14 women aged 44 to 82 (mean, 62) years underwent 21 total wrist arthroplasties for rheumatoid arthritis (n=19) and post-traumatic arthritis (n=2) by a single surgeon using the Universal 2 prosthesis. Pre- and post-operative pain and function were assessed by a single surgeon using the Disabilities of the Arm, Shoulder and Hand (DASH) score and the patient-rated wrist evaluation (PRWE) score. Range of motion, stability, dislocation rate, and neurovascular status were also assessed. Radiographs were evaluated for implant alignment and fit, screw positioning, and implant loosening. RESULTS The mean time to assessment of the range of motion was 3.1 (range, 1.8-3.9) years, and the mean time to assessment of the PRWE score was 4.8 (range, 2.1-7.3) years. The range of motion in each direction and the mean DASH and PRWE scores improved significantly following TWA. Two patients had restricted range of motion, which was treated by manipulation under anaesthetic (after 6 months in one and 8 weeks in the other). One patient underwent excision of a palmar bony bridge. One patient endured extensor pollicis longus rupture and underwent tendon transfer after 5 months. Radiographs revealed no evidence of implant loosening, migration, or malalignment. There was no sign of osteonecrosis in the remaining carpals or metacarpals. CONCLUSION The Universal 2 TWA achieved significant improvement in range of motion and functional outcome of the wrist, with reduced rates of early joint instability, dislocation, and implant loosening, compared to previous implants. The small implant size and cementless design reduce bone loss and osteonecrosis.