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 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.
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.
Causes Of Tarsal Tunnel Syndrome
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 Of Tarsal Tunnel Syndrome
Patients with tarsal tunnel syndrome experience one or more of the following symptoms:
- Tingling, burning, or a sensation similar to an electrical shock
- Pain, including shooting pain
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.
Simple techniques to relieve some of the symptoms are ice, anti-inflammatories, immobilization (such as with a cast walking boot) and cortisone injections.
Sometimes surgery is the best option for treating tarsal tunnel syndrome. Our foot and ankle surgeons will determine if surgery is necessary and will select the appropriate procedure or procedures based on the cause of the condition.