Since 1974, a cementable, semi-constrained total wrist prosthesis has been implanted in patients with advanced destruction of the carpus usually secondary to rheumatoid arthritis. The single most common problem observed after surgery in the first one hundred cases was that of ulnar deformity. Since 1977, 25 total wrist arthroplasties have been performed in 22 patients (3 bilateral cases). A modification of the original prosthesis was employed in these. The newer designs allow for the precise reduplication of the instant center of motion of the normal wrist. Additionally, in the last six patients operated on, methylmethacrylate cement was not used to secure the metacarpal component because a secure press-fit was possible in each case. To date, postoperative results have disclosed no cases of radial ulnar imbalance. No cases of dislocation, infection, or loosening have occurred. No difference in the degree of postoperative pain relief has been observed between those cases in which cement was employed to secure the prosthetic components and those cases in which cement was used only to secure the radial component.