Morphological variations and frequency of communicating branches between musculocutaneous nerve and median nerve

Introduction: In a sample of the Indian population, determine the characteristics and variance of the communication between the musculocutaneous nerve (MCN) and the median nerve (MN), and evaluate its clinical significance. The MCN is typically one of the terminal branches of the brachial plexus's lateral cord in each individual. It originates at C5, C6, and C7, the cervical ventral main rami. The biceps, coracobrachialis (CB), brachialis, and arm flexors are all innervated by the musculocutaneous nerve. It also supplies the skin on the lateral side of the forearm. Material & Methods: The investigation involved 40 cadaver specimens that were obtained for the First MBBS undergraduate program at Zydus Medical College and Hospital in Dahod between 2019 and 2023, spanning a 5-year period. The dissection of the arm and axilla had been carried out, and the tissues were examined and analyzed for the “existence of MCN and MN communication”. Results: The presence of a communicating branch was detected in 11 of 80 upper limbs (11.2%), with bilateral occurrences in 3 cases (27.2%) and unilateral occurrence in 8 cases (72.7%). There was no significant variation in the side of occurrence, as per statistical analysis (p=0.30). A “communication between the MCN and the MN” was seen in 12.5% of the cases; this communication was indicated by the branch that emerged from the MCN after going through the CB (type I). Moreover, “the connection from the MN to the MCN (type II)” was found in 1.25% of the cases. In 11/80 upper limbs (13.7%), a communicating branch was discovered. With little difference in the side of incidence (p=0.30), it happened unilaterally in 8 cases (72.7%) and bilaterally in 3 cases (27.2%). In 12.5% of cases, there was “communication between the MCN and MN”, with the communicative branch seen to pierce the type-I coracobrachialis before leaving the MCN. “The connection was made from the MN to MCN” (type II) in 1.25% of cases. The arm's middle third contained the majority of the communicating branch. The other significant findings that followed were determined. a) The CB is not pierced by the muscle cutaneous nerve (MCN) in 2 cases (2.5%). It is uncommon for the musculocutaneous nerve to vary in its origin, course, relation, distribution, branching pattern, termination, or connection. Stated differently, the preceding authors had recorded differences in the musculocutaneous nerve's origin and distribution. Conclusion: The present study's observations regarding the variation and frequency of MCN-MN communication are within the range reported in prior research, based on sample size. Understanding these MCN-MN relationships is significant for the diagnosis as well as treatment of peripheral “nerve lesions in the upper limb”. In clinical practice, orthopaedic, neurologists, and anaesthesiologists value anatomical variations in the neurovascular structure of the arm. It's also crucial to keep in mind that concurrent vascular variants could exist and complicate the surgical strategy for the best possible minimally invasive surgical procedure.