AN UNUSUAL VARIATION OF EXTENSOR DIGITORUM BREVIS MANUS - A CASE-REPORT AND LITERATURE-REVIEW

An unusual variation of the extensor digitorum brevis manus in a male cadaver is presented. The band-shaped muscle was located at the ulnar side of the hand between the fourth and fifth extensors. It originated from the deep carpal fascia and inserted to the extensor tendons of t he fourth and fifth fingers with a tendon and a slip, respectively. Th e origin, insertion, and location of the muscle differ from those prev iously reported: with these anatomic features, the muscle variation ca nnot be placed into the current classifications. The phylogenetic and ontogenetic implications of the muscle are reviewed. Copyright (C) 199 8 by the American Society for Surgery of the Hand.