Tarsal Tunnel Syndrome

Tarsal Tunnel Syndrome (TTS) or posterior tibial nerve neuralgia is a painful foot condition in which there is repeated pressure resulting in damage to the posterior tibial nerve as it passes through the tarsal tunnel at the ankle. Anything which occupies space in the tarsal canal including cysts and swelling from ankle injuries can compress the tibial nerve. A tarsal tunnel is a narrow space found on the inner side of the ankle. It is a narrow passageway just below the medial malleolus inside the ankle that is bound by bone and soft tissue. Nerves, blood vessels, and tendons pass through this tunnel, including the tibial nerve. 

Anything that causes compression of the posterior tibial nerve or takes up space in the tarsal tunnel can squash the tibial nerve. This reduces the blood flow to the nerve which results in tarsal tunnel syndrome. Common causes for tarsal tunnel syndrome are:

• Space occupying lesions like cysts, benign tumors, ganglions, Varicose veins or neurofibroma or structural enlargement,
• Excess fluid due to ankle injury,
• Inflammation due to arthritis,
• Fallen foot arches can place more pressure,
• Severely flat feet,
• Benign bony growths in the tarsal canal,
• Frequent activities that place high loads on the ankle joint e.g. jumping,
• Conditions like diabetes, rheumatoid arthritis, thyroid disease, etc,
• Improper footwear,
• Athletes

Symptoms vary depending on each individual. Some people experience symptoms that progress gradually, others may experience symptoms that begin suddenly. Symptoms of posterior tibial nerve compression are felt on the inner side of the ankle, under the foot, and into the toes. In severe cases, symptoms may also be felt from the calf to the knee. Symptoms usually include:

• Shooting pain on the bottom of the foot.
• Pain may extend from the medial malleolus, through the heel, and to the inner four toes.
• Pain eases with rest and aggravates with activities such as standing, walking, and driving.
• Pins  and needle sensation,
• Numbness,
• Hot & Cold Sensation in the foot,
• Swelling around the ankle and foot,
• Tingling sensation in the foot and toes with repeated tapping over the tibial nerve.

Pathology:

The tarsal tunnel syndrome is an entrapment neuropathy of the tibial nerve. A tarsal tunnel is formed by the flexor retinaculum, which extends posteriorly and distally to the medial malleolus. The symptoms of compression and tension neuropathies may coexist.

Physical examination:

The examiner checks the progression of the symptoms and checks the medical history like trauma to the area. Examines the foot and ankle, and looks for physical characteristics that could indicate tarsal tunnel syndrome.

Tinel's test:

Tinel's test involves gently tapping the tibial nerve. If the patient experiences a tingling sensation or pain as a result of that pressure, indicates tarsal tunnel syndrome.

Electromyography:

An Electromyography test is done to detect nerve dysfunction.

Magnetic resonance imaging (MRI):

Magnetic resonance imaging (MRI) is done to check whether a mass or bony growth is causing the tarsal tunnel syndrome.

Medication: Non-steroidal anti-inflammatory drugs, Analgesics, etc.

Note: Medication should not be taken without the doctor's prescription

Surgery:

If tarsal tunnel syndrome fails to resolve with conservative treatment, then surgery may be advised, known as Tarsal Tunnel Release or Decompression. Tarsal Tunnel Release may be done arthroscopically, during tarsal tunnel decompression surgery, the flexor retinaculum is first released (cut) and then the area is fully inspected.

Also any abnormal growths e.g. cysts or scar tissue are removed and any fibrous bands that place pressure on the posterior tibial nerve are released.

Rest:

Patients should avoid activities that increase symptoms.  Rest helps to reduce pressure on the nerve and allows it to heal.

Ice therapy:

Regular application of ice to the inner ankle can help to reduce pain and inflammation from tarsal tunnel syndrome and should only be applied for 10 minutes at a time to avoid the risk of further injury.

Compression:

Wearing a compression bandage can help to reduce swelling around the ankle which in turn reduces the pressure on the nerve.

Elevation:

The foot is kept at an elevation that is higher than the level of the heart, which helps to reduce swelling in the ankle and thus reduce the symptoms of tarsal tunnel syndrome.

Orthotics:

Supportive shoes or inserts for the shoes can help to correct foot position by supporting the foot arches. These also help prevent ankle rolling both of which help to reduce the pressure through the tarsal tunnel.

Bracing:

A specially designed ankle brace helps to limit foot and ankle movement and also reduces pressure through the tarsal tunnel.

Kinesio Taping:

Kinesio taping is found to be effective, it helps to provide mechanical support for an unstable ankle joint.

Transcutaneous Electrical Stimulation (TENS):

Transcutaneous Electrical Stimulation (TENS) is also found to be effective to decrease swelling, spasms, and pain.

Therapeutic Ultrasound:

The use of Therapeutic ultrasound helps to decrease pain, and inflammation improves function, and helps to enhance the healing process.

Exercises:

Progressive strengthening and stretching exercises help the foot and ankle muscles to support the ankle joint, and mobilization exercises for the tibial nerve improve the integrity of the nerve.

Obese patients are advised to lose weight to reduce symptoms of tarsal tunnel syndrome as pressure goes through the foot. Also, the patient is advised to perform foot and ankle functions with a brace during high-intensity exercises for protection and support.