Tarsal Tunnel Syndrome
Anatomy of the Tarsal Tunnel
The tarsal tunnel is a narrow space on the inside of the ankle, formed by the ankle bones and a ligament known as the flexor retinaculum. Within the tarsal tunnel, several important structures pass, including the posterior tibial nerve, arteries, veins, and tendons. The posterior tibial nerve provides sensation to the bottom of the foot and controls some of the foot’s movements.
What is Tarsal Tunnel Syndrome?
Tarsal tunnel syndrome occurs when the posterior tibial nerve is compressed or irritated as it passes through the tarsal tunnel, leading to pain, numbness, or tingling sensations in the foot. This condition is similar to carpal tunnel syndrome in the wrist, where a nerve is compressed within a confined space. The cause of the compression can vary and may include injury, swelling, or structural abnormalities that place pressure on the nerve.
What Happens in Tarsal Tunnel Syndrome?
In tarsal tunnel syndrome, the posterior tibial nerve becomes compressed or pinched due to increased pressure within the tarsal tunnel. This compression disrupts the nerve’s function, leading to pain, tingling, or burning sensations in the foot and ankle. The condition can be caused by a variety of factors, including:
- Overuse or repetitive strain from activities such as running or standing for long periods.
- Injury or trauma to the ankle, which may cause swelling and compression of the nerve.
- Flat feet or fallen arches, which can stretch or strain the nerve.
- Cysts, bone spurs, or varicose veins, which may occupy space in the tarsal tunnel and compress the nerve.
Symptoms of Tarsal Tunnel Syndrome
- Pain along the inside of the ankle and the bottom of the foot.
- Burning, tingling, or numbness in the sole of the foot, toes, or heel.
- Symptoms that worsen with activity, such as walking or standing, and improve with rest.
- A sensation of “pins and needles” or an electric shock-like feeling in the foot.
- Weakness in the foot muscles, leading to difficulty with foot movement in severe cases.
How is Tarsal Tunnel Syndrome Diagnosed?
Diagnosis of tarsal tunnel syndrome involves a detailed clinical examination and a review of the patient’s symptoms. Key components of the diagnostic process include:
- Physical Examination: The physician will press along the course of the posterior tibial nerve to check for tenderness, numbness, or tingling sensations. The Tinel’s sign test, in which the physician taps on the nerve to elicit a tingling sensation, may be used to confirm the diagnosis.
- Imaging Studies: X-rays, MRI, or ultrasound may be used to assess for underlying causes, such as bone spurs, cysts, or structural abnormalities that could be compressing the nerve.
- Nerve Conduction Studies (NCS): This test measures the speed of electrical impulses through the posterior tibial nerve and can help confirm nerve compression.
How is Tarsal Tunnel Syndrome Treated?
Treatment for tarsal tunnel syndrome focuses on reducing nerve compression and alleviating symptoms. Non-surgical treatments are typically the first line of management, with surgery reserved for more severe or unresponsive cases.
Non-Surgical Treatment
- Rest and Activity Modification: Reducing activities that place strain on the ankle and foot can help relieve pressure on the nerve. Avoiding prolonged standing, running, or walking may be necessary.
- Anti-Inflammatory Medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen can reduce inflammation and relieve pain.
- Orthotics: Custom orthotics (shoe inserts) can help correct flat feet or fallen arches, providing better support and relieving pressure on the posterior tibial nerve.
- Physical Therapy: Physical therapy may include exercises to strengthen the foot muscles, improve flexibility, and reduce pressure on the tarsal tunnel.
- Steroid Injections: Corticosteroid injections may be used to reduce inflammation around the tarsal tunnel and provide temporary relief from pain.
Surgical Treatment
Surgery is considered when non-surgical treatments fail to relieve symptoms, or if the condition worsens. The goal of surgery is to release the pressure on the posterior tibial nerve by increasing the space in the tarsal tunnel.
Tarsal Tunnel Release: This procedure involves cutting the flexor retinaculum (the ligament that forms the roof of the tarsal tunnel) to create more space for the nerve, relieving compression. Any structures such as cysts, bone spurs, or varicose veins that may be contributing to the compression are also addressed during the surgery.
Post-Surgical Care
Following surgery, the patient will typically need to keep weight off the affected foot for several weeks. Gradual return to activity is encouraged with the help of physical therapy to restore strength, mobility, and balance in the foot and ankle. Full recovery may take several months, depending on the severity of the condition and the type of surgery performed.
Prevention of Tarsal Tunnel Syndrome
Preventing tarsal tunnel syndrome involves minimizing activities that place repetitive stress on the ankle and foot, such as prolonged standing or running. Wearing supportive footwear, especially for those with flat feet, and maintaining strong and flexible muscles in the foot and ankle can reduce the risk of nerve compression. Early intervention in cases of overuse or injury can prevent the condition from worsening.
Summary
Tarsal tunnel syndrome is a condition caused by compression of the posterior tibial nerve as it passes through the tarsal tunnel, leading to pain, tingling, or numbness in the foot and ankle. While non-surgical treatments such as rest, orthotics, and physical therapy can provide relief in most cases, surgery may be necessary for severe cases. Early diagnosis and treatment are key to preventing further nerve damage and maintaining foot and ankle function.
