Tarsal tunnel syndrome (posterior tibial neuralgia) is pain in the ankle, foot, and toes caused by compression of or damage to the nerve supplying the heel and sole (posterior tibial nerve).
The posterior tibial nerve runs along the back of the calf, through a fibrous canal (tarsal tunnel) near the heel, and into the sole of the foot. When tissues around this nerve become inflamed they can press on the nerve, causing pain. Disorders that can cause or contribute to tarsal tunnel syndrome include fracture, ankle swelling from heart or kidney failure, an underactive thyroid gland (hypothyroidism), and disorders such as gout or rheumatoid arthritis that inflame the joints.
Pain, the most common symptom of tarsal tunnel syndrome, usually has a burning or tingling quality. It may occur when a person stands, walks, or wears a particular type of shoe. Pain located around the ankle (usually on the inner side) and extending to the toes usually worsens during walking and is relieved by rest. Occasionally, pain also occurs during rest.
To diagnose this condition, a doctor manipulates the affected foot during a physical examination. For example, tapping the injured or compressed area just below the ankle bone often causes tingling, which may extend to the heel, arch, or toes. Nerve conduction studies (see Diagnosis of Brain, Spinal Cord, and Nerve Disorders: Electromyography and Nerve Conduction Studies) may be useful to determine the cause or extent of the injury, especially if foot surgery is being considered.
Injections of a mixture of corticosteroids and local anesthetics into the area may relieve pain. Other treatments include wrapping the foot and placing specially constructed devices that change the position or range of movement of the foot and relieve pressure on affected joints (orthoses) in the shoe to reduce pressure on the nerve within the tarsal tunnel. When other treatments do not relieve the pain, surgery to relieve pressure on the nerve may be necessary.
Resource: Merck Manual Home Edition