Microsurgery anatomy on functional tract location of thenar branch of median nerve

Objective: To provide microanatomical basis for the location of median nerve and its intrinsic muscles branch after the damage of brachial plexus. Method: Twelve cadaveric upper extremities fixed recently by the formalin were obtained. The nerve specimens were infused topically with 10% acetic acid and individual fascicular groups was dissected by tracing their terminal branches. The arrangement and location of the fascicular group to the intrinsic muscles of hand in the nerve trunk were observed and recorded in each segment. It was observed that how it crossed and mixed with other fascicular groups. Results: Almost all the thenar muscles branches can be located at the radialis or palm-radialis trunk of the median nerve at the distal of 5/16 height. The distance from the point where it going out from the trunk to the line between styloid process of radius and styloid process of ulna was (5.3±0.7)cm. Conclusion: We should recover the intrinsic muscle 's function of hand by recovering thenar muscles branches in the distal arm of the patient who are suffering from nerve injury of brachial plexus when it is hopeless to do it at the proximal of the arm.