What is Tarsal Tunnel Syndrome?
The tarsal tunnel is the canal that can be found between the medial malleolus (the inner part of the ankle) and the flexor retinaculum (a band of ligaments traversing the foot). This tunnel contains important structures, such as the tibia artery, tibial nerve, and tendons of the tibialis posterior, flexor digitorum longus, and flexor hallucis longus muscles. These travel in a bundle through the tarsal tunnel.
When compression of the tibial nerve occurs, symptoms of pain and paresthesia (tingling, tickling, or burning sensation) radiate from the medial ankle. This condition is referred to as the Tarsal Tunnel Syndrome (TTS), or posterior tibial neuralgia.
What causes Tarsal Tunnel Syndrome?
TTS is caused by the compression of the tibial nerve. This can be secondary to local causes, such as space-occupying lesions, bony prominences, or masses within the tarsal tunnel. External trauma from crush injury, stretch injury, fractures, dislocation and sprains can also cause tibial nerve compression.
What are the symptoms of tarsal tunnel syndrome?
The presentation of TTS will vary per case, but patients will typically complain of symptoms such as numbness radiating to the big toe, sharp pain, loss of sensation, burning or tingling sensations over the foot, or even weakness in the muscles of the foot and gait abnormalities.
How is tarsal tunnel syndrome diagnosed?
A diagnosis of TTS is made after a complete medical history and physical examination. A positive Tinel’s sign (a light tapping eliciting a “pins and needles” sensation) and a typical pain history can indicate a possibility of TTS.
Additional imaging studies may be requested, such as Magnetic Resonance Imaging (MRI) scans, and ultrasound scans. In cases of nerve weakness, nerve conduction tests administered by neurologists may also be requested.
How is tarsal tunnel syndrome treated?
TTS is managed with both operative and non-operative techniques, although the exact treatment should be discussed with the attending physician. It is typically recommended that treatment with non-operative interventions be initiated first, and surgery only considered after the failure of non-surgical options.
Conservative, non-operative treatments for TTS include rest, physical therapy and rehabilitation, strengthening of the surrounding muscles, wrapping, and acupuncture. Oral pain medications such as non-steroidal anti-inflammatory drugs (NSAIDs) and medications for neuropathic pain can also provide relief of symptoms. In come cases, injections with corticosteroids and local anesthesia will be necessary. Injections with PRP therapy or stem cell procedures are showing excellent results as well.
If non-operative options fail, surgery is considered. The goal of surgery is to relieve the compression of the tibial nerve, relieving the irritation. The tibial tendon is “released” from the tarsal tunnel during the operation. If there are direct causes of compression, such as cysts or masses, these will be excised during surgery.
After surgery, the joint is immobilized to provide stability during the healing process. The dressing is usually removed after one week, and the sutures after three weeks.
What are the outcomes of TTS surgery?
Most patients who undergo surgery for TTS report favorable outcomes, although complication rates are relatively high. These complications include bleeding, swelling, and infection of surgical site. Postoperative pain may also persist. Patients may continue to report neuropathic symptoms, and crutches may even be required during the initial healing phase. However, majority of patients report improvements in symptoms, as well as increased quality of life.