Failure of palmaris longus muscle duplication and its clinical application.

A case of failure of palmaris longus muscle duplication was found in the left forearm of a male cadaver. Specifically, two distinct palmaris longus muscles had failed to separate, and were united from the medial epicondyle to the palmar aponeurosis. We studied the exact morphology of the abnormal muscle, which, to our knowledge, has not been reported elsewhere in the literature. It also provided data for palmaris longus muscle morphology and may have clinical implications, as the knowledge of such an anomalous muscle should be useful for hand surgeons and radiologists.