Tarsal tunnel syndrome (TTS), also known as posterior tibial neuralgia, is a compression neuropathy and painful foot condition in which the tibial nerve is compressed as it travels through the tarsal tunnel. This tunnel is found along the inner leg behind the medial maleolus (bump on the inside of the ankle).
Tarsal tunnel syndrome is a rare disorder caused by damage to the tibial nerve or its branches, usually due to compression as it passes through the tarsal tunnel (entrapment neuropathy). The tarsal tunnel is a narrow passageway bound by bone and soft tissue that lies on the inside of the ankle. The tibial nerve (as well as certain blood vessels and tendons) passes through the tarsal tunnel. However, the term tarsal tunnel syndrome is often broadly applied to any pain along the tibial nerve, which can result from a multitude of causes. Individuals with tarsal tunnel syndrome may experience pain, burning, or a tingling sensation along the tibial nerve.
The posterior tibial nerve is a distal branch of the sciatic nerve. Blocking it above the medial maleolus in the distal leg results in excellent anesthesia for the skin of the sole of the foot and the underlying deep structures. This makes it a very useful block for deep wound exploration in the foot. Additionally, the innervation of the calcaneous derives from the tibial nerve and this can be a nice selective block for patients with calcaneal fractures. The ankle joint itself has multiple innervations and WILL NOT BE BLOCKED with a posterior tibial block alone.
Signs & Symptoms
The specific symptoms of tarsal tunnel syndrome can vary from one person to another. In some cases, symptoms can develop suddenly, and in others gradually. Some affected individuals may experience a sharp, shooting pain along the tibial nerve. This nerve branches off from the sciatic nerve and runs down the lower leg to the ankle and then the foot. Pain can be severe enough to cause a person to limp. Affected individuals may describe a radiating pain that cannot be localized to one spot. In addition to or instead of pain, affected individuals may experience numbness of the affected area or a burning or tingling sensation (paresthesia), which is often described as similar to “pins and needles”.
In some individuals, symptoms may affect one spot such as the inside of the ankle. In other individuals, symptoms can affect the ankle, heel and foot. For example, pain may radiate from the ankle down to the heel or even the foot, depending on which section of the nerve is affected. Less frequently, pain may radiate up from the ankle to the calf.
The symptoms of tarsal tunnel syndrome are often worsened by activity such as prolonged standing or walking. Consequently, pain may worsen throughout an active day. Symptoms are usually relieved by rest. However, as the disorder progresses, some affected individuals have reported pain that occurs during rest or at night when attempting to sleep.
tibial nerve schwannomas
Causes
Tarsal tunnel syndrome can be caused by any condition that causes compression of the tibial nerve or its branches as it passes through the tarsal tunnel. A wide variety of conditions can cause tarsal tunnel syndrome including space-occupying lesions or masses, which may increase pressure in the tunnel. Such lesions include tumors consisting mainly of fat tissue (diplomas), tumors consisting of nerve fibers and ganglion cells (gangliomas) and tumors of the nerve sheath (schwannomas).
Additional conditions that can cause tarsal tunnel syndrome include a benign bony growth in the tarsal tunnel (exostosis), enlarged (varicose) veins and inflammation of the synovial membrane (proliferative synovitis). Certain injuries or trauma such as an ankle sprain, fracture or valgus foot deformity may cause inflammation and swelling that can lead to tarsal tunnel syndrome. In addition, certain disorders such as diabetes and arthritis can also cause inflammation and swelling that can lead to tarsal tunnel syndrome.
Individuals who have severely flat feet (pes planus) are at a greater risk of developing tarsal tunnel syndrome than the general population because the flattened “fallen” arches can stretch the tibial nerve.
Affected Populations
The incidence and prevalence of tarsal tunnel syndrome is unknown. The disorder is believed to affect males and females in equal numbers.
Related Disorders
Symptoms of the following disorders can be similar to those of tarsal tunnel syndrome. Comparisons may be useful for a differential diagnosis.
Plantar fasciitis is a common condition characterized by inflammation of the thick band of tissue which runs along the bottom of the foot (plantar fascia). The plantar fascia supports the arch of the foot and acts as a shock absorber. Plantar fasciitis is a common cause of heel pain and is often described as a sharp pain in the heel. Pain associated with plantar fasciitis tends to develop gradually and tends to be worse in the morning and may improve throughout the day and with stretching exercises. Additionally, the pain is unlike the shooting and tingling pain associated with tarsal tunnel syndrome.
A wide variety of conditions can cause pain in the foot or ankle including diabetes (diabetic neuropathy), posterior tibial tendinosis, stress fractures, certain rare disorders such as reflex sympathetic dystrophy and certain disorders that affect the nerves outside of the central nervous system (peripheral neuropathy).
Diagnosis
A diagnosis of tarsal tunnel syndrome is made based upon identification of characteristic symptoms, a detailed patient history, a thorough clinical evaluation and a variety of specialized tests. A specific finding that can detect an irritated nerve is Tinel’s sign. During a Tinel’s sign test, a doctor will tap or apply pressure to the tibial nerve. If this causes a tingling or a “pins and needles” sensation in the foot or toes, it is considered positive and is indicative of tarsal tunnel syndrome.
Additional tests that may be performed include electromyography and magnetic resonance imaging (MRI). Electromyography is a test that can determine the health of muscles and nerves and can detect nerve dysfunction. An MRI uses a magnetic field and radio waves to produce cross-sectional images particular organs and bodily tissues and may be used if a space-occupying is the suspected cause of tarsal tunnel syndrome or to detect if the nerve is irritated.
Standard Therapies
Treatment ;The treatment of tarsal tunnel syndrome is directed toward the specific symptoms that are apparent in each individual. Physicians may recommend conservative treatment, which can include rest, contrast baths, nonsteroidal anti-inflammatory drugs (NSAIDs), and nonrigid orthotics. Orthotics refers to devices such as splints or braces that are used to protect or correct the position of the foot. In some cases, changing to looser or larger footwear to reduce tightness can relieve pain associated with tarsal tunnel syndrome.
Some individuals may benefit from a local injection of certain medications (anesthetics) to reduce pain or corticosteroids to reduce inflammation. This may also prove to be diagnostic, as relief brought on by an injection of an anesthetic around the affected nerve confirms the diagnosis. Immobilization such as through the use of a cast can also be beneficial in some cases. Physical therapy may also be recommended.
Individuals with tarsal tunnel syndrome due to flat feet may be treated with orthotics designed to provide support or restore the natural arch of the foot.
Surgery is recommended for individuals with severe symptoms who do not respond to conservative treatment. The purpose of the surgery is to decompress the nerve from within the tarsal tunnel and/or removal of any space-occupying lesion.
References
TEXTBOOKS
Cook RA, O’Malley MJ. Tarsal Tunnel Syndrome. NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. Philadelphia, PA. 2003:592.
JOURNAL ARTICLES
Low HL, Stephenson G. These boots weren’t made for walking: tarsal tunnel syndrome. CMAJ. 2007;176:1415-1416.
Miranpuri S, Snook E, Vang D, Yong RM, Chagares WE. Neurilemoma of the posterior tibial nerve and tarsal tunnel syndrome. J Am Podiatr Med Assoc. 2007;97:148-150.
Gondring WH, Shields B, Wenger S. An outcomes analysis of surgical treatment of tarsal tunnel syndrome. Foot Ankle Int. 2003.24:545-550.
Nagaoka M, Satou K. Tarsal tunnel syndrome caused by ganglia. J Bone Joint Surg Br. 1999;81:607-610
INTERNET
Persich G, Touliopoulos S. Tarsal Tunnel Syndrome.Medscape. Updated: Apr 23, 2014. Available at: http://emedicine.medscape.com/article/1236852-overview AccessedMay 18, 2015.
Wheeless CR. Tarsal Tunnel Syndrome. Wheeless’ Textbook of Orthopaedics. May 23, 2012. Available at: http://www.wheelessonline.com/ortho/tarsal_tunnel_syndrome Accessed May 18, 2015.
Thank you for reading , share your ideas your tips and how to treat and heal this painful syndrome that effected so many workers including nurses, sonographers and those who stand on their feet for long hours.
Steve Ramsey. PhD . Calgary – Canada