Tarsal Tunnel Syndrome
![TarsalTunnel]()
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
- Numbness
- 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.
Sometimes the symptoms of the syndrome appear suddenly.
Often they are brought on or aggravated by overuse of the foot, such as in
prolonged standing, walking, exercising, or beginning a new exercise program.
It is very important to seek early treatment if any of the
symptoms of tarsal tunnel syndrome occur. If left untreated, the condition
progresses and may result in permanent nerve damage. In addition, because the
symptoms of tarsal tunnel syndrome can be confused with other conditions,
proper evaluation is essential so that a correct diagnosis can be made and
appropriate treatment initiated.
Diagnosis
The foot and ankle surgeon will examine the foot to arrive at a diagnosis
and determine if there is any loss of feeling. During this examination, the
surgeon will position the foot and tap on the nerve to see if the symptoms can
be reproduced. He or she will also press on the area to help determine if a
small mass is present.
Advanced imaging studies may be ordered if a mass is
suspected or if initial treatment does not reduce the symptoms. Studies used to
evaluate nerve problems—electromyography and nerve conduction velocity
(EMG/NCV)—may be ordered if the condition shows no improvement with
non-surgical treatment.
Non-surgical
Treatment
A variety of treatment options, often used in combination, are available to
treat tarsal tunnel syndrome. These include:
- Rest. Staying
off the foot prevents further injury and encourages healing.
- Ice. Apply
an ice pack to the affected area, placing a thin towel between the ice and
the skin. Use ice for 20 minutes and then wait at least 40 minutes before
icing again.
- Oral
medications. Nonsteroidal anti-inflammatory drugs (NSAIDs),
such as ibuprofen, help reduce the pain and inflammation.
- Immobilization. Restricting
movement of the foot by wearing a cast is sometimes necessary to enable
the nerve and surrounding tissue to heal.
- Physical
therapy. Ultrasound therapy, exercises, and other physical
therapy modalities may be prescribed to reduce symptoms.
- Injection
therapy. Injections of a local anesthetic provide pain
relief, and an injected corticosteroid may be useful in treating the
inflammation.
- Orthotic
devices. Custom shoe inserts may be prescribed to help
maintain the arch and limit excessive motion that can cause compression of
the nerve.
- Shoes. Supportive
shoes may be recommended.
- Bracing. Patients
with flatfoot or those with severe symptoms and nerve damage may be fitted
with a brace to reduce the amount of pressure on the foot.
When is
Surgery Needed?
Sometimes surgery is the best option for treating tarsal tunnel syndrome.
The foot and ankle surgeon will determine if surgery is necessary and will
select the appropriate procedure or procedures based on the cause of the
condition.
Information provided by The American College of Foot and Ankle Surgeons