Eighteen total wrist arthroplasties in sixteen patients were done using the modified Volz prosthesis. The length of follow-up ranged from twenty-four to sixty-six months, with a mean of forty months. A 100-point scoring system was used to evaluate the outcome. Muscle imbalance developed in five wrists, the carpal component became loose in three wrists, and two prostheses dislocated. In five patients six arthroplasties (33 per cent) were considered to have failed because one reoperation or more was required for loosening of the components in two wrists, dislocation in two wrists, and muscle imbalance in two wrists. Of the remaining twelve arthroplasties (eleven patients) eight (45 per cent) had an excellent result; two (11 per cent), a good; and two (11 per cent), a poor result. The over-all rate of complications was 44 per cent. Patients who had significant preoperative deformity did poorly postoperatively. The surgeon should be prepared to perform other types of arthroplasty or an arthrodesis if the extensor tendons are structurally inadequate, as this may lead to progressive flexion deformity postoperatively.