Entrapment Neuropathies

Entrapment neuropathies of the foot and ankle are common clinical disorders that develop when the nerves around the foot and ankle are compressed due to a variety of causes like edema, inflammation of the surrounding tissues, bony prominences, space-occupying lesions, trauma, etc. Diabetes mellitus is also responsible for the etiology. The common sides for compression are the posterior tarsal tunnel for the tibial nerve, distal tarsal tunnel for the inferior calcaneal nerve, medial plantar tunnel and the knot of Henry for the medial plantar nerve, lateral plantar tunnel for the lateral plantar nerve, abductor hallucis muscle’s fascia and the calcaneus for the medial calcaneal nerve, anterior tarsal tunnel for the deep peroneal nerve, deep crural fascia between the peroneal muscles for the superficial peroneal nerve, intermetatarsal area of the third and the fourth metatarsals for the interdigital nerve, superficial sural aponeurosis for the sural nerve, and the biceps femoris muscle’s tendon for the lateral sural cutaneous nerve. For the clinical examination, applying gentle pressure over the nerve’s course and the common entrapped sides is essential apart from the special provocative tests. Injecting local anesthetics to the determined entrapped side will also be helpful in the clinical diagnosis. Ultrasound will show the nerve’s course and will determine the edema and the entrapment. For the space-occupying soft tissue lesions, magnetic resonance imaging will be helpful.