Meuli total wrist arthroplasty.

The wrist endoprosthesis developed and used since 1971 by the author is comparable to other designs of total joint implants. The completely unconstrained design has proved effective. It has sufficient stability, provided that the proper muscle balance is achieved at the end of the procedure. Careful, exact centering of the prosthesis is a vital prerequisite for good function, along with the use of adequate bone stock for securing implantation and survival of the cement-bone interface. The eccentric placement of the anchoring prongs of the distal component has made centering of the prosthesis easier but has not obviated the need for careful, individual contouring and implantation of each prosthesis. Indications for a total wrist prosthesis must take into account pain, disability, and the local findings. Patients who engage in heavy, manual work and those who must rely on walking aids, such as a cane or crutch, should not be considered as suitable candidates for total wrist implantations. Salvage is always possible either by revision of the arthroplasty or arthrodesis. Cementless implantation of the components may have certain advantages. The prototypes that have been designed are still under investigation.