Tarsal Tunnel Syndrome

Overview

Tarsal tunnel syndrome (TTS) is a compressive neuropathy that affects the posterior tibial nerve as it travels through the tarsal tunnel, a narrow anatomical space located on the inner side of the ankle, beneath the flexor retinaculum. Often described as the ankle’s equivalent to carpal tunnel syndrome in the wrist, TTS results in pain, numbness, and tingling in the foot and ankle due to pressure on the tibial nerve or its branches. The condition can affect one or both feet and ranges in severity from mild discomfort to disabling pain that interferes with walking or daily activities.

Causes

Tarsal tunnel syndrome can arise from a variety of conditions that increase pressure within the tarsal tunnel or directly irritate the tibial nerve. Common causes include:

• Flat feet (pes planus) – Excessive pronation can stretch or compress the tibial nerve.

• Ankle injuries – Trauma such as fractures or sprains can cause swelling or scarring that impinges the nerve.

• Space-occupying lesions – Including ganglion cysts, lipomas, bone spurs, varicose veins, or tumors.

• Inflammatory conditions – Such as rheumatoid arthritis or tenosynovitis, which can increase pressure in the tunnel.

• Systemic diseases – Diabetes mellitus and peripheral neuropathy can predispose individuals to nerve entrapment.

• Repetitive stress – Activities that involve prolonged standing, running, or walking may contribute to chronic nerve irritation.

Symptoms

The symptoms of tarsal tunnel syndrome can vary in intensity and location but commonly include:

• Tingling or burning sensation – Typically felt along the inner ankle, sole, or arch of the foot.

• Numbness – In the heel, arch, toes, or ball of the foot.

• Shooting pain – That may radiate from the ankle into the foot or up the leg.

• Weakness – In severe cases, the intrinsic muscles of the foot may weaken, leading to foot instability.

• Symptoms worsen with activity – Prolonged walking, standing, or exercising can exacerbate discomfort.

• Relief with rest or elevation – Symptoms often diminish when pressure on the nerve is relieved.

Some individuals may notice symptoms only at night or during specific activities, leading to delayed diagnosis.

Diagnosis

Diagnosing tarsal tunnel syndrome involves a combination of clinical evaluation, patient history, and diagnostic tests. Steps in diagnosis include:

• Physical examination – Includes palpation of the tarsal tunnel, assessment of foot posture, and evaluation for swelling or masses.

• Tinel’s sign – A positive test occurs when tapping over the tibial nerve reproduces tingling or pain in the foot.

• Imaging studies – MRI or ultrasound can detect structural causes like cysts, tumors, or inflammation.

• Electrodiagnostic testing – Nerve conduction studies and electromyography (EMG) help confirm nerve compression and rule out other neuropathies.

Early and accurate diagnosis is essential to prevent permanent nerve damage and optimize treatment outcomes.

Treatment

Treatment for tarsal tunnel syndrome depends on the underlying cause and severity. It may involve conservative management or surgical intervention. Common treatments include:

Non-surgical Management

• Rest and activity modification – Avoiding activities that aggravate symptoms.

• Anti-inflammatory medications – Such as NSAIDs to reduce pain and swelling.

• Orthotic devices – Custom shoe inserts to support the arch and reduce nerve tension, especially in cases of flat feet.

• Corticosteroid injections – To reduce inflammation around the nerve.

• Physical therapy – Including nerve gliding exercises, ultrasound therapy, and soft tissue mobilization.

Surgical Management

• Tarsal tunnel release surgery – Involves decompressing the tibial nerve by cutting the flexor retinaculum and removing any offending structures like cysts or scar tissue.

• Neurolysis – May be performed to free the nerve from surrounding adhesions.

Surgery is typically reserved for patients who do not respond to conservative measures or those with a clear compressive lesion identified on imaging.

Prognosis

The prognosis of tarsal tunnel syndrome varies depending on the cause, severity, and timeliness of treatment. Key considerations include:

• Early diagnosis – Offers the best chance for symptom reversal and full functional recovery with non-surgical interventions.

• Chronic cases – May result in permanent nerve damage and persistent symptoms, even after surgical decompression.

• Post-surgical outcomes – Most patients experience relief, but success rates depend on proper identification and correction of the underlying issue.

• Rehabilitation – Ongoing physical therapy and proper footwear are essential to maintain long-term foot health and prevent recurrence.

With appropriate care, many individuals with tarsal tunnel syndrome can return to their normal activities and maintain a good quality of life.