A network of very fine blood vessels that connects bone marrow directly with the blood supply of the periosteum that was previously overlooked has now been discovered. ... However, new blood cells can also leave the bone marrow via this system of vessels and enter the body.
Avascular necrosis (AVN), also called osteonecrosis or bone infarction, is death of bone tissue due to interruption of the blood supply.Osteonecrosis results from the loss of blood supply to the bone. Without blood, the bone tissue dies and the bone collapses. Loss of blood supply to the bone can be caused by medicines or medical procedures, medical conditions, alcohol use, injury, or increased bone pressure