The restoration of elbow flexion is of primary importance in the management of patients with brachial plexus injuries. Superior functional outcomes via fascicle transfer from the ulnar and median nerves have resulted in this transfer being considered the mainstay of recovery of elbow flexion in patients with intact C8 and T1 function. An understanding of the anatomy of the musculocutaneous nerve (MCN) and its branching pattern is key while performing these transfers.
A prospective cohort study was conducted in patients who underwent nerve transfer for the restoration of elbow flexion following a traumatic brachial plexus injury. The anatomic course and branching pattern of the MCN were recorded in eligible cases, both as a line diagram and using intraoperative photographs.
One hundred fifty patients underwent nerve transfer for the restoration of elbow flexion following an injury to the brachial plexus. The MCN in 138 patients (92%) was found to pierce the coracobrachialis muscle before emerging lateral to it. One hundred thirty-four patients (89.3%) demonstrated the “classical” anatomy. One hundred fifteen patients (76.6%) had a single primary branch to the biceps, whereas 25 patients (16.6%) demonstrated a discrete motor branch to each head. One hundred thirty-three dissections (88.6%) revealed a single muscular branch to the brachialis arising posteromedially from the MCN, distal to the origin of the branch to the biceps brachii. Notable unreported variations, such as the MCN penetrating the biceps as it descended, multiple brachialis branches, and trifurcation of divisions of the MCN, were documented.
Variations in MCN anatomy are quite common, and even unreported variations can be encountered.
Exploration of the MCN and its branches for nerve transfers requires knowledge of these anatomic variations and vigilance to prevent inadvertent injuries while dissecting them for nerve transfer surgery.
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Journal of Hand Surgery
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Nerve transfer to the biceps muscle using a part of ulnar nerve for C5–C6 avulsion of the brachial plexus: anatomical study and report of four cases.J Hand Surg Am. 1994; 19: 232-237
- Preliminary results of double nerve transfer to restore elbow flexion in upper type brachial plexus palsies.Plast Reconstr Surg. 2006; 117: 915-919
- Results of reinnervation of the biceps and brachialis muscles with a double fascicular transfer for elbow flexion.J Hand Surg Am. 2005; 30: 978-985
- Results of nerve transfer techniques for restoration of should and elbow function in the context of a meta-analysis of the English literature.J Hand Surg Am. 2001; 26: 303-314
- Nerve transfers in adult brachial plexus injuries: my methods.Hand Clin. 2005; 21: 71-82
- Transfer of a single fascicle from the ulnar nerve to the biceps muscle after avulsions of upper roots of the brachial plexus.J Hand Surg Br. 2000; 25: 325-328
- A rare variation of the median and musculocutaneous nerves in man.Arch Anat Histol Embryol. 1990; 73: 33-42
- Variation of roots in the formation of median nerve.Int J Anat Res. 2018; 6: 5853-5860
- The musculocutaneous nerve and its branches to the biceps and brachialis muscles.J Hand Surg Am. 1995; 20: 671-675
- Anatomy and internal topography of the musculocutaneous nerve: the nerves to the biceps and brachialis muscle.J Hand Surg Am. 1998; 23: 250-255
- Concurrent variations of median and musculocutaneous nerves and their clinical correlation—a cadaveric study.Ital J Anat Embryol. 2011; 116: 67-72
- Communication between the musculocutaneous and median nerves in the arm: an anatomical study and clinical implications.Rev Bras Ortop. 2015; 50: 567-572
- Prevalence of musculocutaneous nerve variations: systematic review and meta-analysis.Clin Anat. 2019; 32: 183-195
- An important variation of the brachial plexus-complete fusion of the median and musculocutaneous nerves.Bull Hosp Joint Dis. 1970; 31: 7-13
- Median and musculocutaneous nerves: variant formation and distribution.Clin Anat. 2003; 16: 453-457
Published online: September 02, 2022
Accepted: July 13, 2022
Received: October 31, 2021
No benefits in any form have been received or will be received related directly or indirectly to the subject of this article.
© 2022 by the American Society for Surgery of the Hand. All rights reserved.