Reconstruction of the Thumb Metacarpophalangeal Ulnar Collateral Ligament With an Adductor Pollicis Slip: An Anatomic Evaluation

Reconstruction of the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal joint is commonly performed for chronic injuries. This study evaluates the anatomic feasibility of using a part of the adductor pollicis tendon to reconstruct UCL. Ten cadaveric arms were dissected to evaluate the relationship between the insertions of UCL and the adductor pollicis. A slip of the adductor pollicis was divided from the tendon and transposed dorsally. The dissected tendon was deemed sufficient for reconstruction if it could be reflected to the footprint of the UCL origin. The size of the adductor pollicis slip was then compared with that of UCL. The dissected slip of the adductor pollicis could be fully reflected proximally to the UCL origin in all the specimens, and the insertion was also found to be closely approximated to the UCL insertion, averaging 2 mm distally and 0.6 mm dorsally. A sufficiently sized partial adductor pollicis tendon can be obtained to reconstruct UCL of the thumb metacarpophalangeal joint, and the location of the adductor pollicis insertion closely approximates that of the UCL insertion. The anatomic relationship evaluated in this study relates to a recently described method of the reconstruction of UCL of the thumb metacarpophalangeal joint that does not require free tendon harvest. This study shows that the technique is anatomically feasible.