The consistent presence of the human accessory deep peroneal nerve

Twenty-four human legs were dissected macroscopically to study the morpholo gical details of the accessory deep peroneal nerve. This nerve arose from t he superficial peroneal nerve and descended in the lateral compartment of t he leg, deep to peroneus longus along the posterior border of peroneus brev is. Approaching the ankle joint, this nerve passed through the peroneal tun nels to wind around the lateral malleolus; it then crossed beneath the pero neus brevis tendon anteriorly to reach the dorsum of the foot. The accessor y deep peroneal nerve was found in every case examined and constantly gave off muscular branches to peroneus brevis and sensory branches to the ankle region. In addition, this nerve occasionally had muscular branches to peron eus longus and extensor digitorum brevis, and sensory branches to the fibul a and the foot. The anomalous muscles around the lateral malleolus were als o innervated by this nerve. Neither cutaneous branches nor communicating br anches with other nerves were found. The present study reveals that the acc essory deep peroneal nerve is consistently present and possesses a proper m otor and sensory distribution in the lateral region of the leg and ankle. I t is not an anomalous nerve as has previously been suggested.