Congenital Absence of Abductor Pollicis Brevis

Abstract

Congenital thenar hypoplasia is a rare anomaly, and even more perplexing when it is isolated to a specific muscle with associated nerve and vascular anomalies. In the present article, the authors report a case involving a 14-year-old female with unilateral absence of the abductor pollicis brevis muscle, a bifid median nerve and persistent median artery presenting with wrist pain. Comprehensive assessment, including radiographic, electromyographic and magnetic resonance imaging studies, were used to evaluate and document this anomaly.