Reconstruction of the ulnar collateral ligament of the thumb metacarpophalangeal joint: A cadaver study

Abstract

The purpose of this study was to compare the stiffness and strength of the native ulnar collateral ligament with 4 methods of static ulnar collateral ligament (UCL) reconstruction at the thumb metacarpophalangeal (MCP) joint. Eleven fresh-frozen cadaver specimens were amputated at the carpometacarpal and interphalangeal joints and all soft tissues were removed except for the extensor pollicis brevis tendon, the proper and accessory collateral ligaments, and the volar plate. Each thumb metacarpal was potted in cement and the native UCL was loaded to failure at 30 degrees of MCP flexion. Ulnar collateral ligament reconstructions as described by Strandell, Osterman, Fairhurst, and a modification of the Glickel procedure then were performed. Each specimen was again loaded to failure and the moment at failure, stiffness, and angle at failure were calculated. None of the reconstructions duplicated the strength or stiffness of the native UCL. The modification of the Glickel procedure with interference knot fixation had a significantly higher moment at failure and was significantly stiffer than any of the other procedures. The differences in strength and stiffness between the Strandell, Osterman, and Fairhurst reconstructions were not statistically significant. There were no significant differences in angle at failure for any of the reconstructions. No static ligament reconstruction restores the normal stability characteristics of the thumb UCL. The anatomic reconstruction of the UCL with interference knot fixation of the tendon graft has far better strength and stiffness than any of the other reconstructions tested. These characteristics may allow for early motion at the MCP joint.