Ulnar Nerve Innervation to Triceps: A Cadaveric Study and a Technical Note on Partial Triceps to Biceps Transfer

Area of Science:

• Anatomy
• Neuroscience
• Orthopedic Surgery

Background:

• Loss of elbow flexion is a common clinical challenge.
• Limited literature exists on ulnar nerve innervation of the triceps brachii muscle in the Indian population.
• Understanding dual innervation is crucial for reconstructive procedures.

Purpose of the Study:

• To determine the incidence of ulnar nerve innervation to the medial head of the triceps in the Indian population.
• To assess the clinical feasibility of transferring parts of the triceps tendon for elbow flexion restoration.

Main Methods:

• A cross-sectional study involving 32 fresh-frozen cadavers of Indian origin.
• Detailed anatomical measurements of the ulnar nerve's course and entry point into the medial head of the triceps.
• Recording of radial and ulnar nerve contributions to the medial triceps head.

Main Results:

• Ulnar nerve innervation to the medial head of the triceps was observed in 43.8% of specimens.
• Mean arm length was 29.13 cm.
• The ulnar nerve pierced the medial intermuscular septum at an average of 9.93 cm from the medial epicondyle.

Conclusions:

• The triceps muscle exhibits dual nerve innervation (radial and ulnar) in a significant portion (43.8%) of the Indian population.
• This dual innervation is clinically relevant for partial triceps-to-biceps tendon transfers.
• Ulnar nerve fascicles to the medial triceps head can potentially serve as donor fascicles in nerve transfer surgeries.