Magnetic resonance imaging and the evaluation of tarsal tunnel syndrome.

The bones, soft tissue contents, and boundaries of the tarsal tunnel can be imaged with sufficient detail to show all the major structures within it. Pathological conditions affecting these structures can also be identified. The purpose of this paper was to determine the ability of magnetic resonance imaging to help in the evaluation of tarsal tunnel syndrome. Thirty-three patients with 40 feet were used for this study. All patients presented with complaints of pain along the course of the posterior tibial nerve or its branches and a positive Tinel's sign. Nerve conduction studies were obtained on 29 feet. All feet were evaluated with a magnetic resonance imaging study of the tarsal tunnel. Twenty-one feet eventually required surgery. Magnetic resonance imaging revealed an inflammatory or mass lesion in the tarsal tunnel in the majority of cases. The magnetic resonance imaging findings were confirmed at surgery in 19 patients. The information provided by magnetic resonance imaging can enhance surgical planning by indicating the extent of decompression required.