CASE REPORT: DEEP PERONEAL NERVE INJURY FOLLOWING INVERSION SPRAIN OF THE ANKLE

Abstract

The deep peroneal nerve is one of the branches of the common peroneal nerve. It passes through the anterior compartment of the leg, between the tibialis anterior and extensor digitorum longus muscles proximally, and the extensor digitorum longus and extensor hallucis longus muscles distally. About one centimetre above the ankle joint, it divides into lateral and medial branches under the superior oblique fibres of the inferior extensor retinaculum. The medial branch continues distally between the extensor digitorum longus and extensor hallucis brevis tendons and provides sensation to the first web space (4). Entrapment of the medial branch of the deep peroneal nerve can occur as the nerve passes under the extensor hallucis brevis tendon. Other causes include compression against dorsal osteophytes on the talonavicular joint, tumours, and the presence of a ganglion. Ankle sprains are certainly one of the most common injuries to the lower leg. Deep peroneal nerve injury complication is actually a rare eventuality. According to Garozzo, although peroneal nerve injuries have always been considered a rare complication of the inversion sprains of ankle, it is likely that they may actually occur more frequently but are not recognized (10). No clear explanation concerning the aetiology of the nerve injury has been defined until now: it may result from the traction of the peroneal nerve during the sudden forcible supination of the foot, or from a gradually expanding haematoma within the nerve sheath consequent to the rupture of a nutrient vessel. In our case, we addressed acute deep peroneal nerve damage due to inversion ankle injury and treatment of this situation.