What is tarsal tunnel syndrome?
Tarsal tunnel syndrome is caused by any condition that causes compression of the tibial nerve. The most common cause is varicose veins within the tarsal tunnel. In other cases it is caused by a cyst or ganglion, arthritis or tendonitis. Flatfoot is a risk factor, due to the outward heel tilt that occurs at the arch drop can cause pressure and compression on the nerve. Systemic diseases such as diabetes, hypothyroidism and renal failure make the nerves more susceptible to injury.
More specifically, the tarsal tunnel is a narrow space located on the medial surface of the ankle. Covered by a thick ligament (the flexor tendon), it provides protection to the tibial nerve, the posterior tibial artery, the posterior tibial tendon, the tendon of the long flexor of the fingers and the tendon of the long flexor of the big toe. If the tarsal canal becomes narrow or tight, the tibial nerve tightens causing pain and numbness. Similar to carpal tunnel syndrome that occurs in the wrist, the symptoms are caused by compression of the tibial nerve, causing pain at the points where the nerve feeds – usually the heel and foot.
What are the symptoms of tarsal tunnel syndrome?
Symptoms of tarsal tunnel syndrome usually include:
Pain or cramping in the foot.
They occur at night, after exercise and at rest. Heel pain is similar to the pain of plantar fasciitis. If left untreated, the condition can worsen and can lead to permanent nerve damage. Because other conditions such as plantar fasciitis are involved in the differential diagnosis of the syndrome, a proper evaluation of the nerve involvement is essential so that a correct diagnosis can be made and appropriate treatment can be initiated.
How is the diagnosis made?
The diagnosis is made by clinical examination which can reveal:
Loss of sensation
Muscle weakness of the leg muscles
Tenderness of the tibial nerve
Pain in the dorsal extension of the ankle.
MRI may reveal the cause of tibial nerve pressure. Electromyography may highlight nerve damage due to compression. However, many times, the syndrome is not detected by either electromyography or MRI.
How is it treated?
Initially, conservative treatment includes:
Treating the underlying cause
Treatment of the underlying cause
Use of guardians
Use of appropriate orthopaedic insoles after a palpogram
Injections of cortisone into the tarsal tube, under ultrasound guidance.
According to the specialist orthopaedic surgeon, in most cases and after 6 months of ineffectiveness of conservative treatment, surgery is required to release the compressed nerve. Specifically, a small incision is made behind the ankle bone, the sheath surrounding the nerve is opened, the nerve is separated from the posterior tibial artery and vein. Both the tibial nerve and its branches are explored, and the causes of its compression are released.
In 75% of patients, surgical opening of the tarsal canal has excellent results and is accompanied by a remarkable reduction in pain. Inadequate opening of the tarsal canal often leads to recurrence of symptoms.
The orthopaedic surgeon, Dr. Antonios Pettas, was responsible for the foot and ankle surgeries at Norrtälje Hospital in Stockholm. He has many years of experience, with a high success rate of operations. Contact him for an early diagnosis and treatment.