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 running from 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.
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.
- Systemic diseases such as diabetes or arthritis can cause swelling, thus compressing the nerve.
Symptoms
Patients with tarsal tunnel syndrome experience one or more of the following symptoms:
- Tingling, burning, or a sensation similar to an electrical shock
Information provided by The American College of Foot and Ankle Surgeons