Use of an Abductor Pollicis Brevis Tendon Slip for Reconstruction of the Radial Collateral Ligament of the Thumb Metacarpophalangeal Joint: An Anatomical Investigation.

Abstract

Reconstruction of the radial collateral ligament (RCL) of the thumb metacarpophalangeal (MP) joint is commonly performed for chronic injuries. This study aims to evaluate the anatomical feasibility and reliability of using the abductor pollicis brevis (APB) tendon to reconstruct the RCL. Ten cadaver arms were dissected to evaluate the relationship between insertions of the RCL and APB. A slip of the APB was divided from tendon and reflected proximally. The dissected tendon was deemed sufficient for reconstruction if it could be reflected to the footprint of the RCL origin. The size of the dissected APB slip was then compared with that of the RCL. The dissected slip of the APB could be fully reflected proximally to the RCL origin in all specimens. The APB insertion was also found to be closely approximated to the RCL insertion, averaging 2.1 mm distal and 1.8 mm dorsal. Significant differences existed between the lengths (<i>P</i> < .001) of the APB slip and RCL, with no significant difference in widths (<i>P</i> = .051). A sufficient APB tendon slip can be obtained to reliably reconstruct the RCL of the thumb MP. The location of the APB insertion closely approximates the RCL insertion.