Tarsal Tunnel Syndrome
If we examine the anatomy of the foot, we see that the bone of the heel called the calcaneus has a deep concavity on its inner surface. Through this concavity, pass the nerves and blood supply to the foot, along with a few tendons (fibrous extension of muscles that insert into the bones). On the inside, these structures are protected by the bone surface and on the outside a sheath of tough fibrous tissue called the flexor retinaculum covers them. This outer sheath, along with the bony concavity, form a small tunnel referred to as the tarsal tunnel.
This small tunnel, located just below the inner bump of the ankle, is an enclosed space. Therefore, any swelling or structural enlargement can easily compress the nerves and vessels passing through it and this is what tarsal tunnel syndrome is. This syndrome refers to compression of the nerve called the posterior tibial nerve, which comes from behind the tibia (bone of the lower leg) and passes through the tarsal tunnel, dividing into three branches. One of the branches supplies the heel of the foot while the other two supply the remainder of the foot.
Compression of the tibial nerve may lead to an abnormal sensation in the area supplied by the nerve.
Any condition that causes pressure in the tunnel and compresses the nerve results in tarsal tunnel syndrome. This includes:
Compression of the tibial nerve would lead to altered sensation in any of the areas supplied by the nerve.
The symptoms are very important in diagnosing the condition. Tinel’s sign also helps to differentiate the condition. X-rays or an MRI scan is helpful to locate any abnormal lesion or mass in the area.
Treatment involves supportive therapy and eliminating the cause of the problem.
Supportive therapy includes:
Surgery is advised for cases not responding to conservative measures. The aim of surgery is to decompress the nerve by:
- Removing any space-occupying lesion
- Cutting the outer fibrous sheath (flexor retinaculum) and leaving it open (the gap later heals with scar formation).
Surgery has been reported to improve symptoms in the majority of cases.
Tarsal tunnel syndrome can very adversely affect an individual’s life quality; therefore, it needs to be treated properly.
Orthotics that will help to treat Tarsal Tunnel Syndrome can be found below.