Radial versus dorsal plating for trapeziometacarpal arthrodesis: a comparative biomechanical study.

Trapeziometacarpal arthrodesis is used for the treatment of advanced arthritis. Insufficient stabilization of the joint may lead to nonunion or hardware problems after arthrodesis. The purpose of this study was to compare the biomechanical properties of dorsal versus radial plate fixation of the trapeziometacarpal joint in ten pairs of fresh-frozen cadaveric hands. The biomechanical performance of each group was measured for stiffness in extension and flexion and load to failure using cantilever bending tests. The stiffness in extension was lower in the dorsally positioned group than in the radially positioned group (12.1 versus 15.2 N/mm, respectively). Load to failure was comparable between both groups (53.9 versus 50.9 N, respectively). A radially positioned locking plate for trapeziometacarpal arthrodesis may be biomechanically advantageous.