Tarsal Tunnel Syndrome

What is the tarsal tunnel?

The tarsal tunnel is a narrow space that lies on the inside of the ankle next to the ankle bones. The tunnel is covered with a thick ligament (the flexor retinaculum) that protects and maintains the structures contained within the tunnel—arteries, veins, tendons, and nerves. One of these structures is the posterior tibial nerve, which is the focus of tarsal tunnel syndrome.

What is tarsal tunnel syndrome?

Tarsal tunnel syndrome is a compression, or squeezing, on the posterior tibial nerve that produces symptoms anywhere along the path of the nerve. The posterior tibial nerve runs along the inside of the ankle into the foot.

Tarsal tunnel syndrome is similar to carpal tunnel syndrome, which occurs in the wrist. Both disorders arise from the compression of a nerve in a confined space. Although tarsal tunnel syndrome may not be as well-known as carpal tunnel syndrome, it is nevertheless a cause of foot and ankle pain in adults.

Symptoms

Patients with tarsal tunnel syndrome experience one or more of the following symptoms:

• Tingling, burning, or a sensation similar to an electrical shock
• Numbness
• Pain, including shooting pain

The symptoms are typically felt on the inside of the ankle and/or on the bottom of the foot. In some people, a symptom may be isolated and occur in just one spot. In others, it may extend to the heel, arch, toes, and even the calf.

Sometimes the symptoms of the syndrome appear suddenly. Often they are brought on or aggravated by overuse of the foot—such as in prolonged standing, walking, exercising, or beginning a new exercise program.

It is very important to seek early treatment if any of the symptoms of tarsal tunnel syndrome occur. If left untreated, the condition progresses and may result in permanent nerve damage. In addition, because the symptoms of tarsal tunnel syndrome can be confused with other conditions, proper evaluation is essential so that correct diagnosis can be made.

Causes

Tarsal tunnel syndrome is caused by anything that produces compression on the posterior tibial nerve, such as:

• A person with flat feet is at risk for developing tarsal tunnel syndrome, because the outward tilting of the heel that occurs with “fallen arches" can produce strain and compression on the nerve.
• An enlarged or abnormal structure that occupies space within the tunnel can compress the nerve. Some examples include a varicose vein, ganglion cyst, swollen tendon, and arthritic bone spur.
• An injury, such as an ankle sprain, may produce inflammation and swelling in or near the tunnel, resulting in compression of the nerve.
• A person who is overweight may be prone to experiencing pressure on the posterior tibial nerve.
• Systemic diseases such as diabetes or arthritis can cause swelling, thus compressing the nerve.

Let the North Hill Foot & Ankle Clinic help you treat your tarsal tunnel syndrome. Book your appointment today.

Courtesy of the American College of Foot and Ankle Surgeons