ABSTRACT
Sites which are peculiarly vulnerable to ischaemic necrosis are the femoral head, the femoral condyles, the head of the humerus, the capitulum and the proximal parts of the scaphoid and talus. These subarticular regions lie at the most distant parts of the bone’s vascular territory, and they are largely enclosed by cartilage, giving restricted access to local blood vessels. The subchondral trabeculae are further compromised in that they are sustained largely by a system of endarterioles with limited collateral connections.
