THE DEEP PERONEAL NERVE IN THE FOOT AND ANKLE - AN ANATOMIC STUDY

Injury to the deep peroneal nerve in the foot and ankle may result fro m trauma, repetitive mechanical irritation, or iatrogenic harm. The ne rve is most susceptible to injury along its more distal anatomic cours e. Dissection of 17 cadaver specimens was undertaken to describe the c ourse of the deep peroneal nerve and quantify its branch patterns. In the distal one third of the leg, the nerve was located superficial to the anterior tibial artery between the tibialis anterior and extensor hallucis Ion-gus muscles. Typically, the nerve crossed deep to the ext ensor hallucis longus tendon to enter the interval between the extenso r hallucis longus and extensor digitorum longus at an average distance of 12.5 mm proximal to the ankle, A proximal bifurcation was usually present at an average distance of 12.4 mm distal to the mortise. The l ateral terminal branch penetrated the deep surface of the extensor dig itorum brevis to provide motor innervation. The medial terminal branch passed over the talonavicular joint capsule, and coursed an average o f 2.9 mm lateral to the first tarsometatarsal joint. Within the forefo ot, it passed deep to the extensor hallucis brevis tendon, bifurcated in the midmetatarsal region, and then arborized, supplying sensibility to the first toe interspace and the adjacent sides of the first and s econd toes.