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

Area of Science:

• Anatomy
• Neurosurgery
• Orthopedics

Background:

• Brachial plexus injuries often require nerve transfers to restore function.
• The nerve to the long head of the triceps is traditionally used for deltoid neurotization.
• Optimal nerve selection for this transfer lacks detailed anatomical investigation.

Purpose of the Study:

• To anatomically characterize the innervation pattern of the triceps muscle.
• To identify the most suitable triceps nerve branch for transfer to the deltoid muscle in brachial plexus injury cases.

Main Methods:

• Dissection of 25 cadaveric arms.
• Detailed analysis of nerve branching patterns to the long, medial, and lateral heads of the triceps muscle.

Main Results:

• The lateral head of the triceps consistently received multiple branches (2-5) in all specimens.
• The long and medial heads received fewer branches, primarily single ones.
• The most proximal branch supplying the lateral head of the triceps was identified as a potential optimal donor nerve.

Conclusions:

• The innervation pattern of the triceps muscle varies, with the lateral head being the most richly supplied.
• The proximal branch to the lateral head of the triceps presents a promising option for nerve transfer to the deltoid muscle.
• This finding may improve surgical outcomes for patients with brachial plexus injuries affecting shoulder function.