Tarsal tunnel is a narrow space that is located on the inside of your ankle. It is next to the ankle bones and covered with a thick ligament. This ligament, flexor retinaculum, protects and maintains the structures inside of the tunnel- like arteries, veins, tendons, and nerves. Among these structures is the posterior tibial nerve, which is the focus of tarsal tunnel syndrome.
What is tarsal tunnel syndrome?
Tarsal tunnel syndrome is when the posterior tibial nerve is compressed or squeezed at any point along the nerve. This syndrome may sound similar, because of its similarities to carpal tunnel syndrome, occurring in the wrist. Both disorders originate from compression of a nerve in the confined space.
Tarsal tunnel syndrome is caused by anything that can produce compression, or pressure on the posterior tibial nerve.
- Flat feet: People with flat feet are at a higher risk for developing this syndrome, because the outward tilting of the heel that occurs with a fallen arch. This can produce strain and compression on the nerve.
- Abnormal structure: Sometimes, a cause of tarsal tunnel syndrome can be enlarged or abnormal structure that occupies the same space in the tunnel. Examples of these abnormal structures include; varicose veins, ganglion cyst, swollen tendon, or arthritic bone spur.
- Injuries: Injuries like ankle sprains can produce inflammation which then can cause swelling in or near the tunnel.
- Health diseases: Such as diabetes or arthritis can cause swelling as well, in turn compressing the nerve.
Tarsal tunnel syndrome symptoms
Symptoms are usually felt on the inside of the ankle and/or bottom of the foot. Sometimes, the symptoms can be isolated to one location and recur only in that same spot, or they can extend to the heel, arch, toes, and even the calf. Here are the most common symptoms:
- Burning sensation
- Sensation that feels like an electric shock
- Numbness or a shooting pain/general pain in the area
Symptoms usually appear suddenly, brought on or aggravated by overuse of the foot (standing, walking, exercising, or beginning to exercise). It is important to seek early treatment if you notice these symptoms. The symptoms of tarsal tunnel can be confused with other health conditions. The evaluation of these symptoms by a podiatrist is essential so a correct diagnosis/correct treatment begins.
Diagnosis is done through an in-depth examination by a podiatrist/foot and ankle surgeon. At the time, the surgeon positions your foot and tap on the nerve to see if the symptoms can be reproduced. They will also apply pressure to the area to determine if an abnormal growth/mass is present in this area.
At times, the doctor may suggest more imaging studies if a mass is suspected or if the initial treatment does not reduce the symptoms. Some studies can evaluate nerve problems- electromyography, EMG/NCV to measure nerve conduction velocity if the condition shows little improvement without surgery.
Tarsal tunnel syndrome treatments
There are a variety of nonsurgical treatments, such as rest, icing, immobilization.
- Immobilisation: Staying off the foot and immobilizing the foot helps prevent further injury and encourages healing of the foot.
- Icing: Ice should be applied to the affected area- place a thin towel between the ice and skin, use ice for 20 minutes, and wait at least 40 minutes before icing again.
- Drugs: Other options include non-steroidal anti-inflammatory drugs, like ibuprofen.
- Physical therapy: Your doctor may prescribe physical therapy to reduce symptoms.
- Injections: Injecting local anaesthesia provides pain relief and treats inflammation.
- Shoe inserts: Orthotic devices can be prescribed to maintain the arch and control the motion of the foot.
- Supportive shoes: Can be recommended as well.
- Foot brace: In some cases, patients with flatfoot or those with severe nerve damage may be fitted with a brace to reduce pressure on the foot.
Surgical treatment is sometimes the best option for treating tarsal tunnel syndrome. A foot and ankle surgeon will determine if surgical treatment is necessary. Your doctor will select an appropriate procedure(s) depending on the origin of tarsal tunnel syndrome