Pathogenesis, diagnosis, and treatment of the tarsal-tunnel syndrome
Thomas E. Gretter, M.D.
Department of Neurology
Alan H. Wilde, M.D.
Department of Orthopaedic Surgery
IN recent years many peripheral nerve compression syndromes have been recognized. The carpal-tunnel syndrome, or compression of the median nerve at the wrist beneath the transverse carpal ligament, is the commonest nerve entrapment syndrome. Less familiar but no less important is the tarsal-tunnel syndrome. Since the first case reports of the tarsal-tunnel syndrome by Keck1 and by Lam,2 in 1962, this syndrome is being diagnosed with increasing frequency. Within the last two years 17 patients with the tarsal-tunnel syndrome have been treated at the Cleveland Clinic. Our report presents a review of the pathogenesis, diagnosis, and treatment of the tarsal-tunnel syndrome.
The tarsal tunnel is a canal formed on the medial side of the foot and ankle by the medial malleolus of the tibia and the flexor retinaculum. The flexor retinaculum spans the medial malleolus of the tibia and the medial tubercle of the os calcis (Fig. 1). The space beneath the ligament is divided by septae into four compartments. Each compartment contains one of the four structures of the tarsal tunnel. These structures are the posterior tibial tendon, flexor digitorum longus tendon, posterior tibial nerve, artery and veins, and the flexor hallucis longus tendon. Each tendon is invested with a separate synovial sheath. The posterior tibial nerve supplies the skin of the sole of the foot and also the dorsum of the toes (Fig. 2A and B). The posterior tibial nerve usually divides into the medial plantar and lateral plantar nerves and the medial calcaneal branches as it . . .