Tarsal Tunnel Syndrome

Tarsal tunnel syndrome is often confused with Plantar Fasciitis. Tarsal Tunnel Syndrome is characterized by the entrapment of tibial nerve during its passage from the tarsal tunnel. Entrapment of this nerve affects both sensory and motor functions of the lower limb and can mimic Plantar Fasciitis in clinical presentation.

Anatomical Variation

In a study reported in Foot & Ankle International¹ journal reports that in some individuals, the Tarsal nerve splits behind the laciniate ligament; while in others, the nerve gives off several branches near medial-malleolar-calcaneal axis¹. In simple words, this variability in anatomy results in entrapment or compression of tibial nerve that may produce variable symptoms. This can make it more challenging to clinically differentiate Tarsal Tunnel Syndrome from other foot conditions like plantar fasciitis and Morton’s neuroma.

Symptoms of Tarsal Tunnel Sndrome:

Foot pain
Tingling sensation
Swelling of the affected foot
Burning sensation
Numbness in toes
Needle like sensation
Worsening of pain and discomfort after heavy labor
Radiation of pain to leg, heel and abdomen
Temperature sensitivity (in which the patient feels hot and cold sensations in feet)

What should you know about Tarsal Tunnel Syndrome?

The factors that are proven to aggravate the risk of tarsal tunnel syndrome are;

History of moderate to severe trauma on the foot
Unstable ankle or foot due to congenital or acquired deformities
Ganglionic cysts
Varicose veins
Bony spur formation

In simple words, any condition that aggravates the pressure on the tibial nerve or compress the contents of tarsal tunnel can lead to tarsal tunnel syndrome (such as flat arches).

How to Diagnose Tarsal Tunnel Syndrome

Accurate and timely diagnosis of nerve entrapment syndromes helps in adopting less invasive therapeutic options for the resolution of symptoms. Tarsal tunnel syndrome can be differentiated from Morton’s neuroma by:

Conducting a detailed history and extensive clinical examination
Performing an EMG (electromyography) study – a procedure that measures the electrical conductivity of the nerves. A decline in electrical conductivity suggests an entrapped nerve. However keep in mind that an electromyography (EMG) study is not always reliable, as decreased conductivity is also observed in arthritis.

Performing Tinel’s Test

A positive tinel’s sign for tarsal tunnel syndrome is characterized by onset of pin and needle sensation along the medial aspect of the foot when the examiner taps on the tarsal tunnel behind the inner prominence of the ankle (the medial malleolus).

Treatment

Most clinicians adopt non-surgical options to address the symptoms of pain and discomfort. The most popular remedies are:

Administration of cortisone injections to alleviate pain and inflammation.
Provision of conservative care with the help of an arch support.

Surgical management options includes; releasing the lacinate ligament and decompression of the posterior tibial nerve by surgical manipulation. Generally the recovery time varies from 4 to 18 months and the outcome depends on the degree of entrapment.

References:

Davis, T. J., & Schon, L. C. (1995). Branches of the tibial nerve: anatomic variations. Foot & Ankle International, 16(1), 21-29.