Selective neurotization of the median nerve in the arm to treat brachial plexus palsy. An anatomic study and case report.

BACKGROUND: The current method for treatment of median nerve palsy after a brachial plexus injury is unpredictable. On the basis of an anatomic study of the median nerve in the arm, we present a new method of selective neurotization of the median nerve.
METHODS: Internal topographic features of the fascicular groups of the median nerve were observed in seventeen cadavera. On the basis of the anatomical results, selective neurotization of the posterior fascicular group of the median nerve in the arm was performed in one patient with a complete brachial plexus palsy.
RESULTS: In the distal half of the arm, the branches of the median nerve consistently collect into three fascicular groups, which are located at the anterior, middle, and posterior parts of the median nerve trunk. The anterior fascicular group is composed of the branches to the pronator teres and the flexor carpi radialis, the posterior fascicular group is composed mainly of the anterior interosseous nerve and the branches to the palmaris longus, and the middle fascicular group is made up mostly of the branches to the hand and the flexor digitorum superficialis. A transfer of the full length of the phrenic nerve was used to selectively reinnervate the posterior fascicular group of the median nerve in a patient with a complete brachial plexus palsy. The muscles supplied by the posterior fascicular group regained Grade-4 power, according to the system of the Medical Research Council, sixteen months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: The typical arrangement of the fascicular groups of the median nerve in the arm favors the technique of selective neurotization, which has been used effectively in one patient to date.