Within the foot (near your ankle) are multiple nerves that run up and down its length. One of the most prominent is the posterior tibial nerve. This nerve runs from the back of your thigh all the way to the base of your foot.
If repeated pressure is exerted on the tibial nerve due to flat feet, inflammation, or injury (among other causes), the nerve becomes numb and sore. This is what is referred to as tarsal tunnel syndrome.
It’s important for you to know if you’re suffering from this condition, as tarsal tunnel syndrome can eventually result in nerve damage and constant pain while walking (or engaging in physical activity).
Understanding the Tarsal Tunnel Syndrome
Before you can understand what tarsal tunnel syndrome is, you first need to know the tarsal tunnel. The name tarsal tunnel arises from a narrow space that’s present on the inner side of the anklebones. This narrow space is surrounded by thick ligaments that protect your arteries, tendons, and nerves.
The posterior tibial nerve (mentioned before) also runs through the tarsal tunnel. Therefore, tarsal tunnel syndrome arises from the discomfort caused by compression of the tibial nerve (running from the ankle to the foot).
Any time a nerve is compressed within a confined space, it tends to swell, become numb, and experience soreness/pain. Tarsal tunnel syndrome also occurs as a result of branches of the tibial nerve (such as the sciatic nerve) being compressed and exhibiting relevant symptoms.
Causes of Tarsal Tunnel Syndrome
Tarsal tunnel syndrome is primarily caused by constant compression of the tibial nerve. This pressure is what often results in swelling, soreness, burning sensations, and sharp shooting pain. But what exactly causes the tibial nerve to constantly become compressed?
Persons who have severely flat feet are often at risk of tarsal tunnel syndrome. This is because flat feet tend to have an outward tinting heel due to fallen arches. The outward tilt stretches your tibial nerve, and the end result is straining or constant compression of the nerve itself.
Varicose veins that are present around the tibial nerve can also cause tarsal tunnel syndrome. Varicose veins are essentially swollen or twisted veins that occur under the surface of your skin.
In the foot, varicose veins arise due to their weakened ability to pump blood. Therefore, pressure builds up in the veins and this pressure may in turn be exerted on the tibial nerve.
In some cases, patients may have lesions or tumors present near the tibial nerve. These masses tend to intrude on the space where the tibial nerve passes through, resulting in compression of the nerve.
Injuries such as ankle sprains, a fractured foot, and inflammation can also cause undue pressure to the nerve. More specifically, ankle sprains tend to disrupt the nerves and blood vessels, resulting in swelling and inflammation. Fractures that occur near the ankle or foot may also cause swelling that exerts pressure on your tibial nerve.
There are other possible causes of tarsal tunnel syndrome. For example, arthritis can cause inflammation on various joints, including the foot/ankle. If you have arthritis and you notice frequent pain near the inner surface of your ankle, you may also have tarsal tunnel syndrome.
Having diabetes can also put you at risk of this condition. Because diabetics have nerves that are tender and more vulnerable to compression, the nerve can become inflamed, painful, and sore.
Symptoms of Tarsal Tunnel Syndrome
Tarsal tunnel syndrome is particularly problematic because it causes numbness, pain, and general discomfort near the ankle. This pain, in turn, causes difficulty in running, walking, and carrying out regular physical activities.
Some of the most common symptoms of tarsal tunnel include:
You may notice that you feel constant or occasional pain inside the ankle (on the inner surface of your anklebones). This is a likely indicator of your tibial nerve being compressed or under constant pressure.
If you notice that you’re feeling a burning sensation on the inner ankle, this may also be due to pressure on the tibial nerve. Burning sensations make it difficult to apply pressure on your ankle when walking or engaging in any other similar activity. You may also have a feeling similar to an electrical shock.
A frequent feeling of pins and needles near the ankle or foot is another symptom of tarsal tunnel syndrome.
Numbness typically occurs when blood doesn’t flow effectively across your blood vessels. Conditions such as varicose veins or swelling near the tarsal tunnel can restrict blood flow and exert pressure on the tibial nerve. This results in numbness around the affected area.
How Tarsal Tunnel Syndrome is Diagnosed
You may opt to visit a doctor if you experience the symptoms mentioned above in your foot or ankle. If your doctor suspects that you may have tarsal syndrome, they may refer you to a podiatrist or an orthopedic surgeon for confirmation.
A podiatrist will typically examine the foot for any of the following symptoms:
During the examination, a diagnosis is strengthened by a positive Tinel’s sign (this means that symptoms are reproduced anytime the nerve is tapped), as well as an electro-diagnosis that studies nerve activity (such as EMGs and NCVs). In some cases, an MRI can be used to image specific structures within the tarsal tunnel. This method is useful at identifying lesions and other growths that may compress the posterior tibial nerve.
If your diagnosis of tarsal syndrome is positive, it’s important to seek treatment as soon as possible. This is because if the condition is left untreated, it can cause irreversible nerve damage to your foot. For example, you may regularly find it painful to walk or engage in normal physical activities. In fact, the symptoms of tarsal tunnel syndrome become more apparent when walking, standing, or running. You may also experience pain at night or while sleeping.
There are several ways through which tarsal tunnel syndrome can be treated. The available methods can be categorized into conservative of surgical treatment. In conservative treatment methods, non-surgical steps are taken to ease pressure around the foot and ankle. Surgical options involve removing any structures that may be causing compression or undue pressure around the nerve.
Conservative treatment options
During conservative treatment, several steps are taken to gradually ease tension on the posterior tibial nerve. Some of these treatment options include:
A podiatrist may recommend frequent rest and limiting of intense physical activity. The movement of your foot may also be restricted by a cast that eases pressure on the nerve.
Ice may also help to reduce inflammation around the foot and ankle area. We may recommend that you place ice on the skin for 20 minutes at a time (with 40 minute intervals in-between).
Medications such as ibuprofen and anti-inflammatory drugs may also be prescribed to reduce pain and swelling.
Physical therapy can be recommended to keep your blood vessels active and to ease pain and tension around the nerves.
You may also be recommended to wear special supportive shoes that prevent pressure on the tibial nerve. This is particularly the case if you have flatfoot.
In some cases, injection therapy can help ease pain and discomfort around the affected area. Injections are administered in the form of a local anesthetic (for pain relief) or a corticosteroid that helps reduce inflammation.
2) Surgical treatment options
If conservative treatment options don’t yield meaningful results, surgical treatment may be recommended. Surgery is mainly aimed at removing any structures that are causing pressure or compression on the nerve.
During surgery, an incision is made right behind the anklebone and near the bottom of the foot. The goal is to relieve all tension from the tarsal tunnel so that the nerve can ease up. In addition, any growths that may be occupying the tunnel can also be removed. These include lesions, swollen veins, or ligaments.
Surgery provides a permanent solution to the more in-depth causes of tarsal tunnel syndrome. After successful surgery, you’ll be placed in a cast for about 3 weeks to allow the area to heal.
Tarsal tunnel syndrome can cause frequent discomfort around the ankle/foot, and nerve damage if left untreated. Dr. Leonara Fihman is a board certified podiatrist with experience in foot and ankle surgery.
Dr. Fihman can examine, diagnose and treat tarsal tunnel syndrome conditions. In this way, you can resume your normal activities without unnecessary pain and discomfort around the foot and ankle area. Do you suspect that you have tarsal tunnel syndrome? Contact our Los Angeles Podiatrist today at 818-798-1919.