Anatomic study of the biceps and brachialis branch of the musculocutaneous nerve for brachial plexus reconstruction

ABSTRACT

OBJECTIVES: The primary objective of this study was to define the anatomy of the musculocutaneous nerve as it innervates the biceps and brachialis muscles in relation to nerve transfer surgery in brachial plexus injury.METHODS: Surgical dissection of the musculocutaneous nerve of both upper extremities of 34 embalmed cadavers was performed to define the anatomy of the musculocutaneous nerve as it supplies the biceps and the brachial muscles. Among the data that we noted were the distance where the branch of the biceps and branchialis took off from the musculocutaneous nerve from the coracoids, which was the bony landmark.RESULTS: There were 17 males and 17 females with a total of 65 musculocutaneous nerve to biceps muscle had an average distance of 10.9cm and a median of 11.0cm±1.83cm (range, 6.5-14.2 cm) from the coracoid. The branching of musculocutaneous nerve to the brachialis had an average distance of 15.1 cm and a median 15.5cm±1.72cm (range, 12.7-21.0cm) from the coracoid. Transferring the fascicles of the ulnar nerve to the biceps branch and a fascicle of the median nerve to the brachialis branch is fairly easy since both nerves are within the vicinity of respective recipient site.CONCLUSION: The anatomy of the musculocutaneous nerve as it supplies the elbow flexors is fairly consistent and there is little discrepancy between cadaveric specimens.