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.