Tibial nerve branching in the tarsal tunnel.

Tarsal tunnel syndrome is an infrequent and probably underdiagnosed clinical condition. Diagnosis and treatment depend on understanding the tibial branching pattern within the tarsal tunnel. A total of 68 foot dissections were performed. Bifurcation into the medial and lateral plantar nerves occurred within the tunnel in 93% and proximal in 7%. Proximal bifurcation may predispose to tarsal tunnel syndrome, and its infrequent occurrence correlates with the infrequent clinical diagnosis. Nine different calcaneal branching patterns were noted; they provide an anatomical explanation for heel sparing. An understanding of anatomic variations should aid in providing complete surgical release and in avoiding accidental heel denervations.