Atypical insertion of the abductor pollicis longus muscle, an anatomical case report

Abstract

During a routine dissection of upper limb in the Department of Anatomy, we came across an unusual attachment of the abductor pollicis longus muscle. Proximal fleshy belly of it originated from the dorsal surface of the shaft of the radius as usual. As it descended it split into two tendons (lateral and medial) proximal to the wrist. The medial tendon attached to the lateral side of base of the first metacarpal bone, whereas the lateral tendon again converted into a fleshy belly at its distal part and inserted into the proximal phalanx of the thumb overlapping the insertion of the abductor pollicis brevis. Double tendons of abductor pollicis longus, each inserting separately into different sites is a rare incidence and needs to be reported to enhance the success rate of any surgical procedures at this region.