Tarsal Tunnel Syndrome

What is tarsal tunnel syndrome?

Tarsal tunnel syndrome refers to the symptoms that result from compression of the posterior tibial nerve. The posterior tibial nerve provides sensation to the bottom of the foot and controls some of the muscles involved in foot structure and movement.

Symptoms of tarsal tunnel syndrome include pain, sensory changes such as tingling or numbness, muscle weakness, and swelling of the foot and ankle.

Treatments include pain control, the use of braces, physical therapy, the treatment of other underlying causes, and surgery.

You should visit your primary care physician who will coordinate your care with a muscle and bone specialist (orthopedic surgeon). Tarsal tunnel syndrome is treated with pain medication, corticosteroid injections, stretching, icing, physical therapy, and also special orthotic inserts for shoes.

Tarsal tunnel syndrome symptoms

Tarsal tunnel syndrome can be defined by persistent pain as well as a few other symptoms that may be present.

Persistent pain

This pain is constant and often worsens over time. The pain can also be described as:

• Most noticeable at night
• Occurring during activities: This may includetwisting the ankle.
• In a certain location: Pain is usually found at the bottom of the foot near the inner ankle.
• Radiating: The pain can sometimes radiate up the ankle and into the toes.
• Tender or palpitating: You may feel these sensations near the medial malleolus.

Other symptoms

Other symptoms that are less common include:

• Sensory changes: You may experience tingling and numbness in the same areas of the foot that are painful. Numbness is uncommon, but when it is present, the inability to feel parts of the foot and ankle can predispose you to injuries.
• Muscle weakness: Strength of the foot and toes may be affected, and the muscles in the foot that are deprived of nerve stimulation will eventually shrink.
• Swelling: You may notice swelling below and behind the inner ankle.

Tarsal tunnel syndrome causes

Tarsal tunnel syndrome is considered a rare disorder. The "tunnel" in tarsal tunnel syndrome is located on the inner ankle. The roof of the tunnel is a tough ligament that stretches from the bump on the inner ankle (middle malleolus) to the heel. Blood vessels, tendons of muscles that act on the foot and toes, and the posterior tibial nerve travel through the tarsal tunnel.

Normally there is enough space in the tarsal tunnel for all of the structures that run through it. However, the ligament that forms the roof of the tunnel is strong and inelastic, so there is not a lot of extra room for error.

Any process that takes up space can lead to compression of the posterior tibial nerve as it passes through the tunnel. For example, abnormal swelling of the nerve or a structural abnormality can cause nerve compression by decreasing the amount of space in the tunnel. Specific causes include underlying conditions, trauma, a local mass, or varied anatomy.

Underlying conditions

Systemic diseases can contribute to the development of tarsal tunnel syndrome. These include:

• Rheumatoid arthritis: This can cause bone and joint abnormalities.
• Diabetes: This can lead to swelling of peripheral nerves including the posterior tibial nerve.
• Hypothyroidism: A low level of thyroid hormone can also cause abnormalities of the posterior tibial nerve that results in compression in the tarsal tunnel.
• Scleroderma: A connective tissue disorder.
• Venous stasis: A condition in the legs that results in poor blood flow.

Trauma

Many types of ankle injuries can result in direct damage to the posterior tibial nerve or compression due to swelling and structural abnormalities. These include:

• Spraining: Spraining one of the tendons that runs through the tarsal tunnel, which will result in swelling and compression.
• Fracture or dislocation: A fracture or dislocation of the ankle can contribute to tarsal tunnel syndrome via damage that occurs at the time of the injury or scarring during the healing process.
• Repetitive damage or stress: Athletes can damage the posterior tibial nerve by wearing overly tight shoes or repeatedly hitting the nerve with the opposite foot while running.

Local mass

A mass within the tarsal tunnel can decrease space and cause nerve compression. There are many possible examples, including bone spurs, cysts, and tumors on the nerve or surrounding structures.

Varied anatomy

Structural characteristics of the foot and ankle can contribute to posterior tibial nerve compression.

• Pes Planus: Also called "flat feet," in which the arches of the feet are decreased or absent. As a result, the ankle rolls in a way that decreases the size of the tarsal tunnel.
• An extra muscle: Some people have an extra muscle in the foot whose tendon runs through the tarsal tunnel, decreasing the space available for the nerve.

Tarsal tunnel syndrome treatment - pain relief & surgery

Unfortunately, tarsal tunnel syndrome is a chronic condition with no guaranteed cure. Specific methods include pain control, assistive treatment, and indirect treatment of underlying conditions.

Pain control

Even when tarsal tunnel syndrome cannot be completely cured, there are several possible methods of pain control.

• Medication: Non-steroidal anti-inflammatory drugs (e.g. ibuprofen) and drugs used for nerve pain (e.g. amitriptyline) can be used to control pain.
• Ice or heat: Applying ice or heat for 20 minutes a few times a day may be helpful.
• Steroid injection: A steroid can be injected into the tarsal tunnel to help relieve pain and swelling.

Can you treat tarsal tunnel syndrome?

Partial or full improvement will occur in many cases of tarsal tunnel, but pain and other symptoms may persist despite treatment. Treatment is most likely to be effective when there is a specific cause that can be addressed, such as a mass in the tunnel.

When to a doctor for tarsal tunnel syndrome

Treatment for tarsal tunnel syndrome is more likely to be effective if it is started early on, so you should seek medical care before the symptoms become severe.

If you have long-lasting foot pain

See a medical provider if you experience foot pain lasting more than two weeks, or if you were previously diagnosed with tarsal tunnel syndrome and your pain is worsening (getting more severe or lasting for longer periods).

If you have any sensory changes

It is important to seek treatment if you experience tingling or numbness in the foot and/or toes.

If you have progressive weakness

Decreased strength and shrinking of the muscles in the foot indicate severe tarsal tunnel syndrome that should be treated promptly.