Surgical anatomy of the radial nerve branches to triceps muscle.

The objectives of the study are to demonstrate the innervation patterns of the triceps muscles and the most suitable branch of the radial nerve for nerve transfer to restore the motor function of the deltoid muscle in patients with complete C5-C6 root injury. Seventy-nine arms (40 left arms and 39 right arms) from 46 embalmed cadavers (24 male and 22 female) were included in the study. The nerves to the triceps were dissected from the triceps muscles (long head, lateral head, and medial head). The lengths of the branches were measured from the main trunk. The distance from the inferior margin of the teres major muscle to the origin of the nerve to the long head, lateral head, and medial head of the triceps were recorded as well. The first branch was the nerve to the long head of the triceps in 79 arms (100%). The second branch was the nerve to the upper medial head in 30 arms (38%), nerve to the medial head in 8 arms (10.1%), nerve to the upper lateral head in 35 arms (44.3%) and nerve to the lateral head in 6 arms (7.6%). The patterns of branches to the triceps were classified according to our dissections. The nerve to the long head of the triceps was constant as the first branch of the nerve to the triceps branch of the radial nerve in the vicinity of the inferior margin of the teres major muscle.