High Tibial Nerve Entrapment: A Common Component of Tarsal Tunnel Syndrome

Tarsal tunnel syndrome (TTS) is the result of compression of the tibial nerve in the area of the medial foot, ankle, or both. Individuals suffering from TTS may experience pain, burning, cramping, or numbness on the sole of the foot and toes. Tarsal tunnel syndrome is divided into a distal component and a proximal component. The latter is referred to as high TTS (HTTS) in which the tibial nerve is compressed above the location of the laciniate ligament. Research on HTTS is scant, and this study is among the first to evaluate the prevalence of HTTS in individuals with clinical signs and symptoms of TTS.

The prevalence of HTTS was studied retrospectively in 175 patients who presented with clinical signs and symptoms of TTS and underwent electrodiagnostic testing. The electrodiagnostic testing involved conventional evaluation and a technique known as "inching" or short segment stimulation.

Of the 175 patients studied, 93 (53.1%) were found to have a focal entrapment in the area proximal to the laciniate ligament.

Electrodiagnostic evidence of a focal nerve entrapment in the area proximal to the laciniate ligament, known as HTTS, occurred in a significant number of patients who presented with clinical signs and symptoms of TTS.