Understanding Tarsal Tunnel Syndrome
What is Tarsal Tunnel Syndrome and Who Develops it
Tarsal tunnel syndrome shares some similarities to the more commonly understood carpal tunnel syndrome that occurs in the hand and wrist. The "tarsal tunnel" is a narrow passageway that runs from the back of the leg into the foot just at the inside of the ankle — where you see the normal bony protrusion above your heel. The tibial nerve, which controls our sense of touch in the sole of the foot, passes through the tarsal tunnel along with the posterior tibial vein and artery.
A band of fibrous tissue runs across the top of these very important structures. Doctors refer to this fibrous band as the flexor retinaculum of the foot or laciniate ligament. If anything under that band becomes irritated, or if any other swelling encroaches on the space within the tunnel, the tibial nerve can become compressed. Compression of the tibial nerve may cause symptoms that range from tingling in the sole of the foot to a burning pain that radiates up the ankle or down further into the foot.
Tarsal tunnel syndrome is somewhat uncommon, but can happen to almost anyone. Some reports suggest that people with flat feet may be more likely to develop the syndrome because the tarsal nerve becomes more stressed by pronated (flattened) arches. Other factors may also be important in determining the cause of the syndrome. Changes in the foot or ankle due to arthritis or diabetes may have an impact. And, certainly, scar tissue from past trauma to the foot or ankle could also contribute to the cause.
What are the Symptoms of Tarsal Tunnel Syndrome?
The symptoms of tarsal tunnel syndrome often begin gradually and typically stem from the inside of the ankle or the heel of the foot. Initially, symptoms may be intermittent (come and go), but without intervention, they may become chronic (constant). You may feel tingling, numbness and pain in your foot. This pain may also radiate through your ankle and up into your leg. Pain associated with tarsal tunnel may feel dull and nagging, or it may seem to shoot through your foot and ankle like an electrical current. When your doctor touches your foot along the route of the tibial nerve, you may feel instant tingling and pain.
In order to diagnose you properly, your doctor will consider your symptoms and examine your foot and ankle. Your doctor may also require you to have X-rays, an MRI (magnetic resonance imaging) or a nerve conduction test to look closely at the nerve function in your foot.
Your doctor may recommend different treatment options depending on your particular symptoms and the severity of your condition.
How is Tarsal Tunnel Syndrome Treated?
As a first course of treatment, doctors usually recommend that you avoid engaging in any activity that causes symptoms or makes your symptoms feel worse. That may mean resting your foot as much as you can. This initial "avoidance" therapy will help your doctor get a better picture of the extent and severity of your nerve compression.
Manage the Pain.
Your doctor may prescribe or recommend the use of anti-inflammatory medications (like aspirin or ibuprofen) and cold packs that will help to reduce inflammation as well as reduce the pain associated with your tarsal tunnel syndrome. Often a local injection of cortisone or lidocaine, or both, helps to further reduce inflammation.
Get the Right Support.
A specially designed orthotic, like a customized arch support, can be worn in your shoe to help position your foot in such a way that it relieves some of the pressure on the tibial nerve causing your pain.
Understand Your Surgical Options.
If you are still experiencing pain after all other conservative measures have been taken, your doctor may suggest surgery to help relieve your pain and restore your mobility and activity level. Surgery to relieve the symptoms of tarsal tunnel syndrome involves releasing the fibrous band of tissue (flexor retinaculum) that runs across the tarsal tunnel. The surgeon makes an incision across the tissue — enlarging the space underneath and alleviating pressure.
Your doctor will use specialized instruments, such as Stryker's KnifeLight instrument, which are designed to correct your tarsal tunnel surgically. Your doctor will most likely inspect the length of the nerve to ensure that nothing compresses it, and may apply a resorbable collagen nerve wrap, such as NeuroMend. This may help alleviate pain by further protecting the tibial nerve and not allowing soft tissue to adhere to it.
Be sure to talk with your doctor about the best treatment option for you.
Anticipate Feeling Better.
In most cases, you will be able to go home the same day. Your ankle may be supported by a special plaster splint for a week or two following surgery, and then a removable boot after that. You will probably be instructed on how to use crutches when you walk to keep pressure off your healing foot and ankle for awhile.
Taking time to take care of yourself after surgery will go a long way toward helping you feel better quickly. Follow your doctor's instructions for elevating and icing your foot during the day. And, follow your doctor's guidelines for exercise. You doctor may even prescribe a course of physical therapy to help you get moving while you recover.