The vascularization of the os calcaneum and the clinical consequences.

This study was conducted to analyze extraosseous and intraosseous vascularization of the os calcaneum and to elucidate possible clinical manifestations. The arteries of 13 lower leg and foot specimens of human cadavers were injected with a polymer and subjected to maceration or were embedded in plastic. The examination revealed that 45% of the bone is vascularized via medial arteries and 45% via lateral arteries, whereas the remaining 10% is supplied by the sinus tarsi artery. From the medial side, two or three vessels branch off the posterior tibial artery, penetrate the calcaneus below the sustentaculum, and supply the medial part of the posterior joint. The lateral calcaneal artery normally is a branch from the posterior tibial artery. In two of 13 specimens, this lateral supply comes from the peroneal artery. The medial and lateral intraosseous arterial supply for the calcaneus is equal. Inside the bone there is a water-shed zone where the medial and lateral arterial supply meet in the midline. Only 10% of the blood flow is supplied by vessels in the sinus tarsi. Clinically, interruption of the lateral calcaneal artery during the conventional lateral surgical approach for a calcaneus fracture may result in ischemic bone necrosis. The lateral calcaneal artery could supply a local microvascular flap to cover soft tissue defects of the heel. A compartment syndrome after a calcaneus fracture may be caused by bleeding from the medial calcaneal arteries into the quadratus plantae compartment.