What is osteonecrosis?

Osteonecrosis, also called avascular necrosis, is death of the bone tissue and marrow. In marrow infarctions, the cancellous bone and marrow are involved. The cortical bone is usually not damaged and neither is the underlying cartilage.

Dead bone is recognisable from its empty spaces since during the healing process the osteoclasts resorb the necrotic trabeculae in an attempt to deposit new, living bone, sometimes leading to the collapse of the necrotic cancellous bone and alteration of the cortical bone, occasionally with fractures and/or even alterations of the articular cartilage.