A critical analysis of alignment factors influencing functional results following trispherical total wrist arthroplasty.

In a study of the impact of selected patient factors and alignment variables on functional results of total wrist arthroplasty, functional score and range of motion were found to be improved and incidence of component shift and progressive radiolucent lines decreased by proper positioning of the implant center of rotation and restoration of carpal height. Angulation of the implant stems was secondary in importance to the other positioning variables with respect to overall function and durability. A neutral alignment range for this implant arthroplasty was proposed. Within this neutral range, functional score averaged 94 points and range of motion averaged 68 degrees. There were no reoperations, component shifting, or progressive radiolucent lines, and all wrists rated an excellent score.