Variant branching and distribution pattern of the radial nerve and musculocutaneous nerve

Knowledge of anatomical variation involving the superficial branch of the radial nerve will help in several clinical interventions such as nerve transfer procedures, guiding surgical incisions, diagnostic trauma reconstructive surgery, flap harvest and in performing nerve blocks etc. We report here a variant distribution pattern of the superficial branch of radial nerve and discuss the clinical implications. In the present case, in addition to sensory distribution, the superficial branch of radial nerve also provided motor innervation to extensor carpi radialis brevis and brachioradialis muscles. Further, the branch supplying the brachioradialis, pierced its tendon distally and communicated with the parent trunk to supply skin of dorsum of the hand. Because of the unusual motor distribution to these muscles, which act on wrist joint, an iatrogenic damage or traumatic injury of the nerve might jeopardize the sensori-motor qualities of the upper limb.