Association of the branches of median nerve to the forearm with pronator teres and the intramuscular innervation patterns in pronator teres

Objective To provide the morphological basis for clinical application of median nerve and pronator teres (PT). Methods The branches of median nerve to the forearm are separated and studied in thirty adult cadavers. The innervation pattern of PT was observed in five adult cadavers using the Sihler's staining technique. Results In the dense median nerve-branching pattern,the mean length of the farthermost branch to medial epicondyle of humerus is (7.63 ± 1.15) cm,29% of the entire length of the forearm. The mean length of PT is (14.01 ± 0.91)cm. The insertion of PT to the lateral epicondyle of humerus is (13.31 ± 0.81)cm,52% of the forearm length. The median nerve gave off a primary branch bilaterally to enter PT from the upper side of the muscle; the ulnar branch distributed to the proximate half part of the humeral head and the radial branch to the ulnar head and the distal half part of the humeral head. Conclusions The muscular branches of median nerve in the forearm converge in the proximate end,deflect to the ulnar side,and have a close relation with the location of PT. These features have certain referential significance in repairing forearm injury. PT has fixed distribution of nerve branches arising from median nerve and may be divided into the compartments of the humeral head and the ulnar head for neuromuscular transplantation.