Tarsal Tunnel Syndrome: An Ultrasound Pictorial Review.

Tarsal tunnel syndrome may be idiopathic or may be caused by various conditions: bone disease, thickening of the retinaculum, hematoma, or iatrogenic nerve damage; tendinopathy or tenosynovitis; the presence of supernumerary muscles such as an accessory soleus, peroneocalcaneus internus, or accessory flexor digitorum muscle; bone or joint disorders; expansile tumors or cysts; and venous aneurysm or kinking of the tibial artery. The purpose of this article is to describe and illustrate most of the causes of tarsal tunnel syndrome, as diagnosed by ultrasound, which is a practical, inexpensive method.