Tarsal tunnel syndrome is a painful condition of the foot caused by pressure on the posterior tibial nerve as it passes along a passage called the tarsal tunnel just below the bony bit on the inside of the ankle. Symptoms include pain which is often described as a burning pain radiating into the arch of the foot, heel and sometimes the toes. Pins and needles or numbness may be felt in the sole of the foot. Pain may be worse when running or when standing for long periods of time and often worse at night. The area under the medial malleolus on the inside of the ankle may be tender to touch. The Tinels Test is used to diagnose tarsal tunnel syndrome. This involves tapping the nerve just behind the medial malleolus or bony bit of the ankle with a rubber hammer. Pain indicates a positive test.
Tarsal tunnel syndrome occurs when the posterior tibial nerve which passes down the inside of the ankle becomes compressed or trapped. If you overpronate where your foot rolls in when you walk or run then this can contribute to compression of the nerve. Because overpronation is a key factor, it is common for the problem to occur in both feet at the same time. In people involved in running or running based sports, where the condition occurs spontaneously, then overpronation is the most frequent cause.
Rest from any aggravating activities and apply cold therapy whilst in the acute phase when the foot or ankle is painful and inflamed. Once the initial pain and inflammation has gone then a full rehabilitation program which includes stretching and strengthening exercises for the foot can begin. Nerve conduction studies may be done to confirm the diagnosis and indicate the location of the entrapment.
An X-ray or MRI may also be useful to determine the presence of any other structures such as cysts, arthritis or a tarsal coalition. If conservative treatment fails then a corticosteroid injection may be administered. For stubborn and persistent cases surgery may be required to decompress the nerve. The operation is undertaken to decompress the nerve by freeing the soft tissue structures in the area, creating more space for the nerve. The procedure itself is very fast.