Accessory cutaneous branch of the deep peroneal nerve: A rare anatomical variation

The deep peroneal nerve typically follows a well-defined course in the anterior compartment of the leg, providing motor innervation to the extensor muscles of the foot and sensory supply to the first interdigital cleft. However, its branching pattern and sensory distribution variations are clinically significant but rarely reported. These anatomical anomalies can have implications for surgical procedures, nerve block techniques, and the interpretation of clinical symptoms in the lower limb. An unusual branching pattern of the deep peroneal nerve on the left lower limb of a 57-year-old male cadaver was observed in this case. An accessory cutaneous nerve arising from the deep peroneal nerve at the upper shaft of the fibula was observed. The cutaneous branch of the Superficial Peroneal Nerve supplied only the lateral aspect of the dorsum of the foot. The accessory cutaneous nerve compensated the supply of the medial aspect of the foot, hence designated as the accessory deep peroneal sensory nerve. The main trunk of the deep peroneal nerve was seen in its usual course, supplying the region's muscles and the 1st interdigital cleft. The current finding is rare and highlights the importance of understanding the anatomical variations of peripheral nerves. Such variations are clinically significant due to their potential impact on diagnostic evaluations, surgical interventions, and nerve block procedures involving the lower limb. • Variant Innervation: Deep peroneal nerve compensates for absent medial superficial cutaneous branch. • Surgical Relevance: Key to preventing nerve injury in foot and ankle procedures. • Clinical Impact: Important for nerve conduction studies and neuropathy assessments.