Tarsal Tunnel Syndrome

What is is: Posterior Tibial Neuralgia, more commonly known as Tarsal Tunnel Syndrome is a painful condition caused by the entrapment or compression of the posterior tibial nerve.

Anatomy: The posterior tibial nerve is a branch of the sciatic nerve and innervates the posterior compartment of the legs. As it continues down the leg, it passes posteriorly and inferiorly to the medial malleolus. It ends and branches off into sensory branches that innervate the sole of the foot. The tibial nerve travels through the tarsal tunnel and is covered superiorly by the flexor retinaculum. At this point, branches stemming from the tibial nerve innervate the heel.

Symptoms: Tarsal tunnel syndrome is characterized by pain with walking or running and sometimes
Osteoarthritis, diabetes, and rheumatoid arthritis both also cause inflammation of the flexor retinaculum and surrounding tissues, which compress and irritate the nerve.
Accessory Muscles: In a small percentage of people, they are born with an accessory muscle, called the Flexor Digitorum Accessorius Longus (FDAL). It also passes through the tarsal tunnel, which creates a smaller space for the nerve. If the FDAL get inflamed at all, it can pinch the posterior tibial nerve also causing tarsal tunnel syndrome.

Diagnosis: Tinel’s Tarsal Tunnel Test- tap test done immediately posterior to the medial malleolus. If positive, pain from the nerve will radiate through the medial ankle and possibly to the heel and sole of foot. Past history, examination, and EMG are also helpful in the diagnosis.

Treatment: Orthotics are beneficial if pronation-related. Surgical release of the tarsal tunnel is possible if no physiotherapy is helping, although this doesn’t always have a good outcome. If related to FDAL, then surgery is often successful, as the muscle is cut from the tunnel, and attached to another muscle nearby that won’t cause