Abnormal ulnar nerve anatomy in the distal forearm pre-disposes to post-traumatic ulnar neuritis at the wrist.

Anatomical variations of the ulnar nerve have been described at the level of the elbow and in Guyon's canal, while the path in the forearm has always been assumed to be constant. We present a case of compressive ulnar neuropathy at the wrist pre-disposed by a presumed congenital variation of the path of the ulnar nerve at the level of the wrist which improved following surgical release of the constriction caused as a result of it.