[An anatomical study of tarsal tunnel]

In order to understand the pathogenesis and improve the treatment of tarsal tunnel syndrome, we investigated the tarsal region anatomically on 62 feet of 31 cadavers and five freshly amputated feet. The following results were thus obtained: 1. The bifurcation into the medial and lateral plantar nerves mostly occurred within the flexor retinaculum. 2. The medial calcaneal branch showed many anatomical variations. 3. The flexor retinaculum was not clearly demarcated at its superior and inferior borders, and it was not as thick as previously thought. 4. The neurovascular bundle was separated from other tendon sheaths, and enclosed in its own tunnel. 5. A fibrous septum found at the entrance of the abductor hallucis muscle, may represent an entrapment point of the medial plantar nerve. 6. The ganglion from the talocalcaneal joint tended to compress only the medial plantar nerve.