Triceps motor nerve branches as a donor or receiver in nerve transfers

The pattern of triceps innervation is complex and, as yet, has not been fully elucidated. The purposes of this study were 1) to clarify the anatomy of the triceps motor branches, and 2) to evaluate their possible uses as a donor or receiver for nerve transfer.

The radial nerve and its motor and cutaneous branches were bilaterally dissected from the axilla and posterior arm regions of 10 embalmed cadavers.

A single branch innervates the triceps long head, whereas double innervation was identified for the lateral and medial heads. The upper branch to the lateral head originated from the radial nerve, whereas the lower branch to the lateral head stemmed from the lower medial head motor branch, which ultimately innervated the anconeus muscle. Both the long head and the upper medial head motor branches originated in the axillary region in the vicinity of the latissimus dorsi tendon.

Each of the triceps' motor branches might be used as a donor for transfer. The triceps long head motor branch should be used preferentially when the intention is to establish triceps reinnervation.