Dorsal Digital Branch of the Thumb: An Anatomical Study

Abstract

SUMMARY:The level of origin of digital branch to thumb (DBT) of superficial branch of radial nerve (SBRN) and its relationship to brachioradialis muscle tendon (BRT) and its fascial sheath (FS) were studied on both sides of upper extremities of 50 cadavers (n=100). The DBT of SBRN originated in the middle third of forearm in 3 cases (3%), distal third of forearm in 10 cases (10%) and in wrist and dorsum of hand in 87 cases (87%). All cases having origin in the middle third of forearm and half of the cases having origin in the distal third of forearm were closely related to BRT or its FS. The clinical importance of the study lies in the fact that the DBT supplies dorsum of the thumb and first web space which has least cutaneous overlapping. Any injury or entrapment of this nerve may lead to painful neuritis. Anatomical knowledge of such variations are important for neurologists and surgeons performing operative procedures in Quervain's release, arthroscopy and Wartenberg's disease.