Anatomic double-bundle reconstruction with free tendon graft for chronic ulnar instability of the thumb metacarpophalangeal joint.

Failed primary treatment of thumb metacarpophalangeal ligament injuries may lead to chronic instability. Different treatments have been described such as secondary ligament suture, fusion, dynamic or static procedures. Techniques to restrain the joint stability with various grafts of different configurations have been published, but most of these address only the proper collateral ligament. Experimental data revealed the importance of the accessory collateral ligament in stabilizing the metacarpophalangeal joint. In a former, true anatomic ligament reconstruction a bone-tendon graft was used; the tendon was split longitudinally to reconstruct both parts of the collateral ligament. This technique was modified by the author: a resorbable interference screw was used to fix a free tendon graft double in the metacarpal head, creating 2 identical bundles for reconstruction of both the proper and the accessory collateral ligament. The results of the first 10 patients with chronic ulnar instability in their otherwise intact thumb are reported. The mean follow-up was 15 months. Eight patients had excellent result and 2 patients had good result according to the Glickel grading system. The mean loss of motion in the metacarpophalengeal joint was 9% and the mean loss of pinch strength was 9% compared with the contralateral thumb. The technical details, pitfalls, complications, and rehabilitation are described in this paper.