Tarsal Tunnel Syndrome

**A patient Ė not a doctor, has compiled this list of Frequently Asked Questions and Answers. Please speak to your doctor regarding any concerns you have about your condition Ė this information contained here should never be used as a replacement for medical attention, diagnosis, or treatment. Please contact me if you have any comments or corrections to the information in this document - you can email me at mailwendy1@shaw.ca

 

Last updated: 2001 March 25

 

Exactly what is it?

Tarsal Tunnel Syndrome (TTS) is also known as Posterior Tibial Nerve Neuralgia. TTS is a compression syndrome of the tibial nerve within the Tarsal Tunnel. In other words, itís a collection of symptoms that occur because the nerve in this area is being irritated. It seems to affect both men and women equally and it can begin at any age.

What is the Tarsal Tunnel?

This tunnel is found along the inner leg behind the medial malleolus (bump on the inside of the ankle). The posterior tibial nerve, a major artery, veins, and tendons travel in a bundle along this pathway, through the Tarsal Tunnel. In the tunnel, the nerve splits into three different paths. One nerve (calcaneal) continues to the heel, the other two (medial and lateral plantar nerves) continue on to the bottom of the foot. The Tarsal Tunnel is made up of bone on the inside and the flexor retinaculum (a tough band) on the outside.

Whatís happening in the tunnel and why does it hurt so much?

Inflammation or swelling can occur within this tunnel for a number of reasons. The flexor retinaculum (that tough band on the outside) doesnít stretch much, so increased pressure will eventually cause compression on the nerve within the tunnel. As pressure increases on the nerves, the blood flow decreases. Nerves respond with altered sensations like tingling and numbness. Fluid collects in the foot when standing and walking and this makes the condition worse. As small muscles lose their nerve supply they can create a cramping feeling.

What are some of the symptoms?

- Painful/tingling in and around ankles Ė sometimes the toes

- Swelling of the feet

- Painful burning, tingling, or numb sensations in the lower legs

- The pain worsens and spreads after standing for long periods

- Pain is worse with activity and is relieved by rest

- Weakness

- Electric shock sensations

- Pain radiating up into the leg, and down into the arch, heel, and toes

- Pain can occur and persist at rest

- Typically the heels are spared (conflicting information on this)

- Hot/cold sensations in the feet

- Feeling as though the feet donít have enough padding

- Pain while driving

- Throbbing

- Pain along the Posterior Tibial nerve path

- Burning sensation on the bottom of foot, radiating up

- Parasthesia (pins and needles)

- Dysaesthesia (abnormal pain)

- Hyperaesthesia (increased sensation)

- Tinelís sign

What is Tinelís sign?

This is a tingling electric shock sensation that occurs when you tap over an affected nerve. Your doctor may tap over the TT area to see if it elicits these shocks. The sensation usually travels into the foot but can also travel up the inner leg as well.

 

I donít have all the symptoms listed Ė does that mean I donít have TTS?

This is a list of symptoms that can occur with TTS, patients donít necessarily have all of them. Only your doctor can determine whether or not you actually have this condition.

 

How is Tarsal Tunnel Syndrome diagnosed?

Often a doctor will arrive at a diagnosis based on the patientís symptoms, and after ruling out other possibilities. There are many foot conditions that may have symptoms similar to those experienced with TTS. Your doctor will want to rule out things like plantar faciitis, stress fractures, or tendonitis. Sometimes these other foot problems can exist along with TTS.

Some systemic conditions can cause foot pain. Your doctor may order blood work including tests for low vitamin B12 (this can cause peripheral neuropathy), diabetes, thyroid, lupus, and rheumatoid arthritis. Along with a complete exam and history, the doctor may order x-rays and/or a bone scan or nerve conduction testing.

In some cases, a MRI is done to get a better look at what is happening in the tunnel, and to check for possible masses causing compression. Although an MRI isnít really used to confirm a diagnosis of TTS, it can show other things that may be happening in the foot like tumors, stress fractures, or a ruptured tendon.

What is Nerve Conduction Testing? Does it hurt?

A neurologist usually administers nerve conduction tests. During this test, electrodes are placed at various spots along the nerves in the legs and feet. Both sensory and motor nerves are tested at different locations. Electrical impulses are sent through the nerve and the speed and intensity at which they travel is measured. If there is compression in the tunnel, this can be confirmed and pin pointed with this test. Many doctors do not feel that this test is necessarily a reliable way to rule out TTS. Some research indicates that nerve conduction tests will be normal in at least 50% of the cases. It is very possible to have TTS without a positive nerve conduction test. Many doctors feel that this test is unnecessary and often not helpful with diagnosis.

Whether or not it hurts seems to depend on a number of factors. There is a component to the test that isnít always done Ė it involves inserting needles under the skin. The unanimous opinion (according to the people Iíve talked to) is that this portion of the test causes substantial pain. Ask your doctor if this part of the test will be required.

For the electrodes themselves, the degree of pain experienced seems to depend on the type of machine used (there are different kinds), the skill of the technician, as well as the stress and pain threshold level of the patient. Try to relax as much as possible during the test, and discuss any concerns you have with the technician or your doctor.

(Writerís note: Iíve had this test twice on both my hands and feet Ė and I would describe it as mildly uncomfortable Ė not painful but I didnít have the needles either).

 

What causes TTS?

It can be difficult to determine the exact cause of Tarsal Tunnel Syndrome, however it is still important to try to determine the source of the problem. Treatment and the potential outcome of the treatment may depend on the cause. Anything that creates pressure in the Tarsal Tunnel can cause TTS. This would include benign tumors or cysts, bone spurs, inflammation of the tendon sheath, nerve ganglions, or swelling from a broken or sprained ankle. Systemic conditions that may cause peripheral neuropathy (defined later) also make damage or irritation of the nerve more likely. These systemic conditions would include alcoholism, diabetes, rheumatoid arthritis, or thyroid disorders. Varicose veins (that may or may not be visible) can also cause compression of the nerve.

TTS can be due to a repetitive stress injury and itís more common in athletes, active people, or individuals who stand a lot. These people put more stress on the tarsal tunnel area and it can make the tendon prone to swelling, and increase the likelihood of the nerve being stretched. Onset of TTS can also follow sudden activity in a previously inactive person.

People with flat feet may have increased pressure in the TT region and this can cause nerve compression. The short Achillesí tendons that are seen with flat feet can cause more stress on the foot and the TT area.

Lower back problems can cause symptoms Ė specifically problems with the L4, L5 and S1 regions.

My doctor wrote down "Peripheral Neuropathy" whatís that?

Donít let this scare you too much. Peripheral means outer or surrounding, and neuropathy is basically a problem with the nerves. So, peripheral neuropathy is a problem with the outer nerves (like in the hands and feet). There are many different types of neuropathies, with carpal tunnel syndrome and tarsal tunnel syndrome being just two. Many different things including nutritional imbalances, drugs, or infection can cause neuropathies. In the case of TTS or CTS, the problem is caused by compression of the nerve. It is important for your doctor to determine whatís causing your symptoms. He/she will need to determine what is causing your neuropathy in order to know the best way to treat it.

How can it be treated?

Treatment options will depend on the cause of TTS. Systemic problems like arthritis, lupus, alcoholism or low thyroid need to be controlled. Your doctor will need to ensure that the symptoms are not being caused by lower back problems. Generally TTS treatment options will include the following:

Rest

This is the first and often the most important step, especially if an underlying structural problem or overuse is causing the symptoms. Recovery can take a long time, and it may be necessary to really restrict activity for a while. You cannot "push" through the pain of this condition, and you may very well make your pain and inflammation worse. From my discussions with other patients - recovery time is often measured in terms of months (or even years) not in days or weeks. Try to avoid activities that increase pain, and elevate the feet whenever possible.

Anti Inflammatory Medication

Doctors may prescribe one of many different types of oral anti-inflammatories. These can be effective in reducing inflammation and swelling within the tunnel, as well as with pain relief. Sometimes it may be necessary to try different kinds in an effort to find one that is most helpful with the least side effects. As with any prescription drugs, you and your doctor will want to weigh the potential benefit from the drug with the possible risks.

 

Orthotics

Custom made orthotics can be helpful (and may in fact be essential) if the cause of TTS is an underlying structural problem. Orthotics are usually made by a podiatrist, physiotherapist or pedorthotist. Some medical insurance providers will cover a portion or all of the costs associated with prescription orthotics. Following a structural exam and gait analysis, casts are made of the foot while it is held in a neutral position. These casts are made many different ways (depending on the preference of the professional) Ė and the orthotics can be made from various types of materials. Orthotics may be three quarter length, or go the entire length of the shoe. It often can take several adjustments or even recasting of the foot to ensure a proper fit.

Although orthotics are often recommended for treatment of TTS, there seems to be a very high number of people on this board who were using custom made orthotics when they developed TTS. In particular, people who were wearing types that were made of rigid plastic seem to be more likely to develop TTS symptoms.. If your orthotics seem to be making the condition worse patients may consider having the orthotics adjusted, having new orthotics made, or switching to different footwear and not using the orthotics at all for a trial period.

Itís essential to find an experienced professional who will work with you. Orthotic casting seems to be something of an "art" and success may depend on the skill and persistence of the individual youíre working with.

 

Birkenstocks

Many individuals with Plantar faciitis and or TTS (myself included) have found great relief from wearing Birkenstock sandals. The sandals provide adequate support for most, and there isnít any pressure applied to the ankle area. Going barefoot can often increase pain from TTS, and wearing a Birk sandal around the house may be helpful.

Cortisone injections

Doctors may administer a cortisone injection into the TT area. This can be used to control pain and swelling, and to help confirm a diagnosis of TTS. It is used as a diagnostic tool, because the belief is that if the injection temporarily eliminates the pain Ė it can be seen as confirming that pain stems from the Tunnel and not from somewhere like the lower back. Injections should be used judiciously; there may be some risk of rupturing the Posterior Tibial Tendon.

Acupuncture

Acupuncture administered by a licensed professional can be helpful in controlling pain syndromes, and in stimulating the bodyís natural ability to heal. Risks are minimal providing the practitioner is properly trained and certified.

Surgery

Surgical decompression of the Tarsal Tunnel is generally considered a "last resort" following at least six months to one year of conservative treatments. Specific surgical corrections may vary depending on circumstance, but usually an incision is made behind the ankle bone (medial malleolus), then down to but usually not onto the bottom of foot. The Posterial Tibial nerve is identified above the ankle, separated from itís accompanying artery and vein, and followed into the tunnel. The nerves are released. In addition, cysts or arthritic problems may be corrected at this time. If there is scarring within the nerve or branches this is relieved by internal neurolysis. Neurolysis is when the outer layer of nerve wrapping is opened and the scar tissue is removed from within nerve. Following surgery, a large bulky cotton wrapping immobilizes the ankle joint without plaster. The dressing may be removed at the one week point, sutures at about 3 weeks.

Potential complications may include bleeding, infection, and unpredictable healing (especially if the patient is diabetic, arthritic or on steroids that slow down healing). The incision may open from swelling. There may be considerable pain and/or cramping, and regenerating nerve fibers may create shooting pains. Patients may have hot or cold sensations, and may feel worse than before surgery. Crutches are usually recommended for the first two weeks, as well as elevation to minimize swelling. Nerves will grow at about one inch per month Ė and this can be associated with some pain. Patients can expect to continue the healing process over the course of about one year.

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