Triceps innervation pattern: implications for triceps nerve to deltoid nerve transfer.

There are multiple nerve branches supplying the triceps. Traditionally, the nerve to the long head of triceps is utilized for nerve transfer to neurotize the deltoid muscle in patients with brachial plexus injuries. However, no anatomical studies were done to investigate which triceps nerve would be preferred for nerve transfer. This anatomical study was carried out to describe the innervation pattern of the triceps muscle to investigate the preferred triceps nerve for nerve transfer. Twenty-five cadaveric arms were dissected. The long head of the triceps received a single branch in 23 cases (92%) and double branches in 2 cases (8%) only. The medial head had a single branch in 22 cases (88%) and double branches in 3 cases (12%). The lateral head was the most bulky one and received more than one branch in all cases (100%), ranging from 2 to 5 branches. The transfer of the most proximal branch to the lateral head of the triceps seems to be the most preferred choice for deltoid muscle innervation.