An anatomical study of the deep transverse metacarpal ligament.

The anatomy of the deep transverse metacarpal ligament was examined in cadaveric dissections. Previously unreported findings were transverse muscular slips from abductor digiti minimi that inserted into the medial border of the ligament and, in 1 case, an extension from the medial half of the tendon of extensor carpi ulnaris that inserted into the medial aspect of the ligament. Applied anatomy in relation to the dynamics of the transverse metacarpal arch is reviewed.