Tarsal tunnel syndrome is a compression neuropathy of the posterior tibial nerve at the ankle. It is also called posterior tibial nerve neuralgia.
Tarsal tunnel syndrome is a rarely reported entrapment neuropathy of the deep peroneal nerve under the extensor retinaculum at the ankle. Entrapment neuropathy is a form of compression neuropathy.
The roof of the tunnel is the inferior extensor retinaculum. The floor is the fascia overlying the talus and navicular. Within the tunnel are four tendons, an artery, a vein, and the deep peroneal nerve.Causes
The neuropathy is due to chronic pressure on the nerve at the point where it passes through the tarsal tunnel.
Nerve entrapment, neuropathy, and nerve dysfunction in the legs, ankles and feet of athletes are not uncommon conditions. Frequently, these conditions are overlooked as the more obvious musculoskeletal injuries attract more attention.Symptoms
Symptoms typically are painful burning, tingling, or numbness in the foot. Pain is more intense at night. The pain is worse during movement and is relieved by rest. Pain may be noted while standing, walking or wearing various types of shoes.Diagnosis
Diagnosis is made by tapping or palpating the posterior tibial nerve at a site of compression or injury. This will often produce distal tingling (Tinel's sign). Electrodiagnostic testing often will confirm the diagnosis and should be performed on all patients undergoing foot surgery.Treatment
In cases where there is no fibro-osseous compression of the nerve within the canal, local infiltration of insoluble corticosteroid with lidocaine may be effective. Strapping the foot in a neutral or slightly inverted position or constructing an orthotic device for the shoe that keeps the foot in an inverted position will reduce nerve tension.
Surgery for decompression may be necessary for cases that do not respond to these treatments. The surgery involves the release of the retinaculum. During surgery, the nerve should be minimally manipulated. The surrounding veins, arteries, and fat should also be minimally manipulated.
Rarely, symptoms are severe and diffuse enough to require administration of a tricyclic antidepressant medication to decrease the nerve irritability.Questions
What is causing the pain in my foot?
Is there nerve entrapment and compression?
How severe is the entrapment?
Will corticosteroids help?
Is surgery necessary?
What will surgery accomplish?
Will there be a full recovery?