Tarsal tunnel syndrome

A condition caused by compression of the tibial nerve in the tarsal tunnel

Tarsal Tunnel Syndrome

Tarsal tunnel syndrome is a medical condition that occurs when the tibial nerve is compressed as it travels through the tarsal tunnel, a narrow space on the inside of the ankle next to the ankle bones. This syndrome is analogous to carpal tunnel syndrome in the wrist, where the median nerve is compressed.

Anatomy

The tarsal tunnel is located on the medial side of the ankle and is formed by the flexor retinaculum, a band of fibrous tissue that stretches from the medial malleolus to the calcaneus. Within this tunnel, the tibial nerve, along with the posterior tibial artery and tendons of the flexor muscles, passes into the foot. The tibial nerve branches into the medial plantar nerve, lateral plantar nerve, and the medial calcaneal nerve as it exits the tarsal tunnel.

Causes

Tarsal tunnel syndrome can be caused by any condition that results in compression of the tibial nerve within the tarsal tunnel. Common causes include:

• Flat feet or fallen arches, which can stretch the tibial nerve.
• Varicose veins or ganglion cysts that occupy space within the tunnel.
• Inflammation from arthritis or other inflammatory conditions.
• Trauma or injury to the ankle, leading to swelling or scar tissue formation.
• Diabetes, which can cause nerve damage and increase susceptibility to compression.

Symptoms

The symptoms of tarsal tunnel syndrome can vary but often include:

• Tingling, burning, or a sensation similar to an electric shock in the foot.
• Numbness in the foot or toes.
• Pain that radiates from the inside of the ankle into the foot.
• Symptoms that worsen with activity and improve with rest.

Diagnosis

Diagnosis of tarsal tunnel syndrome typically involves a combination of clinical evaluation and diagnostic tests. A healthcare provider may perform a physical examination, focusing on the foot and ankle, and may use the Tinel's sign test, where tapping over the tibial nerve elicits tingling or pain. Imaging studies such as X-rays, MRI, or ultrasound may be used to identify structural causes of compression. Electromyography (EMG) and nerve conduction studies can assess the function of the tibial nerve.

Treatment

Treatment for tarsal tunnel syndrome aims to relieve pressure on the tibial nerve and may include:

• Rest and avoidance of activities that exacerbate symptoms.
• Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation.
• Orthotic devices or shoe modifications to support the foot and reduce pressure on the nerve.
• Physical therapy to strengthen the muscles and improve flexibility.
• Corticosteroid injections to reduce inflammation.
• In severe cases, surgical intervention may be necessary to release the flexor retinaculum and decompress the nerve.

Prognosis

The prognosis for tarsal tunnel syndrome varies depending on the underlying cause and the effectiveness of treatment. Many individuals experience relief of symptoms with conservative management, but some may require surgery for lasting relief. Early diagnosis and treatment are important to prevent permanent nerve damage.

Related pages

• Carpal tunnel syndrome
• Peripheral neuropathy
• Plantar fasciitis
• Flat feet