A rare variation in the mode of termination of posterior cord of brachial plexus

The brachial plexus is an ordered network of large nerves through which the sensory and motor nerve supply is distributed to all structures that constitute the upper limb. It is formed by the anterior rami of C5 to T1 spinal nerves. They unite to form the upper, middle and lower trunks. Each trunk splits into anterior and posterior divisions. All three posterior divisions merge to form the posterior cord; in it are gathered all C5 to T1 nerves fibers for the extensor compartment. It lies behind the axillary artery [1]. The posterior cord terminates in the axillary and radial nerves. The three minor branches of the posterior cord are the two subscapular nerves and the thoracodorsal nerve between them [1]. Variations in the formation of brachial plexus and its terminal branches has been reported in 65.3% of cases [2]. Here, a rare variation in the branching pattern of the terminal branches of the posterior cord of the brachial plexus is reported.