Brachial plexus variations in the flexor compartment of arm with its clinical implications and embryological basis: A cadaveric study

• Published in: Translational research in anatomy Vol. 28; p. 100203
• Main Authors: Lalit, Monika, piplani, Sanjay, Mahajan, Anupama, Verma, Poonam
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01-09-2022; Elsevier
• Subjects: Biceps brachii; Brachial plexus; Coracobrachialis; Median nerve; Musculocutaneous nerve; Coracobrachialis; Biceps brachii; Brachial plexus; Musculocutaneous nerve; Median nerve
• ISSN: 2214-854X; 2214-854X
• DOI: 10.1016/j.tria.2022.100203

The nerve supply of the upper limb, which is provided by the brachial plexus, is extremely important from a medical and surgical perspective. Muscles of the flexor compartment of the arm are destined to have their nerve supply from the musculocutaneous nerve, a branch from the lateral cord of the brachial plexus. Variations in the formation and branching of the brachial plexus are not uncommon. These variations have clinical significance during surgical procedures, in the brachial plexus block, and in diagnostic clinical neurophysiology.
The study was carried out in the department of anatomy consisting of 56 limbs during routine undergraduate dissection classes. Dissection of the infraclavicular part of the brachial plexus was done. The variations in the origin, number, and distribution of the branches derived from the cords to the flexor compartment of the arm and their correlations to the coracobrachialis were noted.
47 limbs (83.92%) showed a normal morphological pattern of formation and distribution of brachial plexus to the flexor compartment of the arm. 9 limbs (16.07%) showed variations in one form or the other. Two limbs (3.57%) showed an absence of musculocutaneous nerve (MCN). In 3 limbs (5.35%) coracobrachialis was not being supplied by MCN, and 4 limbs (7.14%) exhibited a communication between MCN and Median Nerve (MN).
Variations in the nerves supplying the flexor compartment of the arm have clinical implications in post-traumatic evaluations and exploratory innervations of the arm for peripheral nerve restoration. It is important for surgeons, clinicians, and anatomists to be aware of these possible anatomical variations to avoid unexpected complications.
•2 limbs (3.57%) showed an absence of musculocutaneous nerve (MCN).•Coracobrachialis was not being supplied by MCN in 3 limbs, a branch arose from the lateral cord of the brachial plexus and supplied coracobrachialis muscle.•4limbs (7.14%) exhibited communication between the musculocutaneous nerve (MCN) and median nerve (MN).