Posterior Tarsal Tunnel Syndrome

THE CLINICAL SYNDROME

Posterior tarsal tunnel syndrome is caused by compression of the posterior tibial nerve as it passes through the posterior tarsal tunnel. The posterior tarsal tunnel is made up of the flexor retinaculum, the bones of the ankle, and the lacunate ligament. In addition to the posterior tibial nerve, the tunnel contains the posterior tibial artery and a number of flexor tendons that are subject to tenosynovitis. The most common causes of compression of the posterior tibial nerve at this anatomic location is trauma to the ankle, including fracture, dislocation, and crush injuries. Thrombophlebitis involving the posterior tarsal tunnel syndrome than does the general population. Posterior tarsal tunnel syndrome is much more common that anterior tarsal tunnel syndrome.

SIGNS AND SYMPTOMS

Posterior tarsal tunnel syndrome presents in a manner analogues to carpal tunnel syndrome. The patient will complain of pain, numbness, and paresthesias of the sole of the foot. These symptoms may also radiate proximal to the entrapment into the medial ankle. There are medial and lateral plantar divisions of the posterior tibial nerve that provide motor innervation to the intrinsic muscles of the foot. The patient may note weakness of the toe flexors and instability of the foot due to weakness of the lumbrical muscles. Nighttime foot pain analogous to the nocturnal pain of carpal tunnel syndrome is often present.

Posterior tarsal tunnel syndrome presents in a manner similar to carpal tunnel syndrome and is characterized by pain, numbness, and paresthesias of the sole of the foot.

Physical findings include tenderness over the posterior tibial nerve at the medial malleolus. A positive Tinel’s sign just below and behind the medial malleolus over the posterior tibial nerve is usually present. Active inversion of the ankle will often reproduce the symptoms of posterior tarsal tunnel syndromes. Weakness of the flexor digitorum brevis and the lumbrical muscles may be present if the medial and lateral branches of the posterior tibial nerve are affected.

Posterior tarsal tunnel syndrome is often misdiagnosed as arthritis of the ankle joint, lumbar radiculopathy, or diabetic polyneuropathy. Patients with arthritis of the ankle joint will have radiographic evidence of arthritis. Most patients suffering from a lumbar radiculopathy will have reflex, motor, and sensory changes associated with back pain, whereas patients with posterior tarsal tunnel syndrome will have no reflex changes. Motor and sensory changes will be limited to the distribution of distal posterior tibial nerve. Diabetic polyneuropathy will generally present as symmetrical sensory deficit involving the entire foot rather than limited to just the distribution of the posterior tibial nerve. It should be remembered that lumbar radiculopathy and posterior tibial nerve entrapment may coexist as the “double crush” syndrome. Furthermore, because posterior tarsal tunnel syndrome is seen in patients with diabetes, it is not surprising that diabetic polyneuropathy is usually present in diabetic patients with posterior tarsal tunnel syndrome.

TREATMENT

Mild cases of tarsal tunnel syndrome will usually respond to conservative therapy, and surgery should be reserved for more severe cases. Initial treatment of tarsal tunnel syndrome should consist of treatment of tarsal tunnel syndrome should consist of treatment with simple analgesics, nonsteroidal anti-inflammatory drugs, or cyclooxygenase-2 inhibitors and splinting of the ankle. At a minimum, the splint should be worn at night, but 24 hours a day is ideal. Avoidance of repetitive activities thought to be responsible for the evolution of tarsal tunnel syndrome will also help ameliorate the patient’s symptoms. If the patient fails to respond to these conservative measures, a next reasonable step is injection of the tarsal tunnel with local anesthetic and steroid.

To treat the pain and disability of posterior tarsal tunnel syndrome with injection, the patient is placed in the lateral position with the affected leg in the dependent position and slightly flexed. It should be remembered that the most common cause of pain radiating into the lower extremity is herniated lumbar disc or nerve impingement secondary to degenerative arthritis of the spine, not disorders involving the tibial, common, or deep peroneal nerve per se. Other pain syndromes that may be confused with posterior tarsal tunnel syndrome include lesions above either the origin of the tibial or common peroneal nerve.

Low intensity laser therapy as well as a coordinated wellness program is also effective in treating this disorder.

Low Intensity Laser Therapy (LILT)

The low intensity Laser (LILT) sends photons (light) into the injured tissues and can penetrate two to three inches to treat affected areas. It uses a natural enhancement of the cellular machinery that can and has been dynamically measured in published studies to promote healing without burning affected tissue. Once the photons find the injured tissues, they stimulate and energize the cells to repair and strengthen at a remarkable rate. The treatment does not hurt, takes about 30 minutes and is very cost advantageous.

Wellness Program

A wellness program whichindividualizes treatment for age, performance and function has been shown in pilot studies to improve the overall health and well being of the individuals evaluated. A well conceived dietary and supplementary regimen based on scientific age–related decline in certain necessary compounds can improve quality of life, correct the ravages of hormone imbalance, balance critical neurotransmitter function without resorting to powerful drugs for depression that often have unfavorable side-effect profiles and restore vitality and youth in daily exercise routines. Furthermore, when wellness products are utilized with success, individuals often seek less costly interventions including unnecessary surgeries and narcotic options to treat pain. For more information go to www.drpwellness.com.