Biomechanical evaluation of chronic boutonnière reconstructions.

The magnitudes of the extensor forces generated across the proximal interphalangeal joint by the Littler-Eaton, Matev, Hellmann, and Fowler reconstructive procedures for posttraumatic chronic boutonnière deformity were measured in a laboratory study. The purpose of the experiment was to determine whether the mechanical design of a procedure had a significant impact on biomechanical performance. Results showed that each method produced adequate extensor forces and restored full proximal interphalangeal joint extension. There were few statistically significant differences among the procedures for the different joint angles and load conditions tested. The data suggest that the mechanical designs of these reconstructions are satisfactory for correction of the extensor deficit of the deformity. The preoperative condition of the finger is probably responsible for the variations seen in clinical results.