Tarsal tunnel syndrome (TTS) is a condition that occurs when the posterior tibial nerve is compressed in the tarsal tunnel, a narrow passageway on the inner side of the ankle. The posterior tibial nerve is a large nerve that provides sensation and movement (motor function) to the foot. When the nerve is pinched, irritated or compressed, it can cause pain, numbness, and tingling in the foot.
TTS is more common in women than in men, and it is most common in people over the age of 50. Other risk factors for TTS include:
People with flat feet have a lower arch in their foot, which can put more pressure on the posterior tibial nerve.
Ankle and rearfoot arthritis can cause swelling and inflammation, which can also compress the posterior tibial nerve.
Diabetes can lead to damage to small nerves, including the posterior tibial nerve.
Ganglion cysts are fluid-filled sacs that can form in the tarsal tunnel and compress the posterior tibial nerve.
The main symptoms of TTS are:
These symptoms are often worse at night and may be relieved by walking or standing.
A doctor can diagnose TTS by taking a medical history, performing a physical examination, and ordering tests. The physical examination will focus on assessing pain, numbness, and tingling in the foot. The doctor may tap across the inner side of the foot and ankle, looking to reproduce the patients normal symptoms. Tests that may be ordered include:
Treatment for TTS typically involves conservative measures, such as:
Corticosteroid injections can be a highly effective way of reducing inflammation and pain as a result of posterior tibial nerve irritation with tarsal tunnel syndrome. At The Joint Injection Clinic, corticosteroid injections are performed after a thorough consent process, whereby the risk and benefits of the procedure are discussed in detail with your doctor. The experienced medical doctor will then place you in a lying position with the inner aspect of the ankle face up, resting on the couch. The skin is cleaned using a cleaning solution to ensure that the procedure is performed under sterile conditions. The posterior tibial nerve injection is performed with a small dose of steroid, targeting the area surrounding the nerve (perineural tissue), being careful to avoid injecting into the nerve itself.
The injection itself is normally completed within 30-60 seconds, after which a plaster is applied and post-injection advice is given. The patient is advised to look out for any signs of infection, specifically to check whether the local area becomes red, hot, tender, swollen or if they develop a fever. If this occurs then the patient is asked to contact the clinic immediately at which time a formal reassessment will occur and if needed oral antibiotics can be prescribed. The patient is also warned that following any injection they may notice a short-term worsening or flare in their symptoms after the local anaesthetic has worn off (4-5 hours). This may last for 3-5 days and the patient is advised to consider icing of the area using an ice pack for 10-15 minutes every hour as required.
In some cases, surgery may be necessary to treat TTS. Surgery involves decompressing the posterior tibial nerve by cutting the ligament that may be compressing the nerve.
If you experience any of the symptoms of tarsal tunnel syndrome, it is important to see a doctor to get a diagnosis and discuss treatment options. Early intervention can help to prevent further injury and improve overall foot function.