Doctor Thomas P. Sculco, Surgeon-in-Chief at the Hospital for Special Surgery in New York, speaks about the nature of avascular necrosis and a common way to treat it.

Dr. Sculco Many times with necrosis we end up replacing the hip. Avascular Necrosis talks more about bone. And avascular means there's no blood flow. And if you lose the blood flow to the bone, the bone will die. And in the case of the hip, we're talking about the ball of the femoral head. The way I like to describe it to a patient is like you had a ping-pong ball. And you took your thumb and you put a depression in the ball. And that's what Avascular Necrosis is a depression in the head, the bone dies, bone collapses, cartilage coverings lost, support system, and then the cartilage collapses. Because the joint no longer fits you get wear patterns to destroy the joint. Many times for necrosis we end up replacing the hip. Sometimes even if the incongruity or the depression is not that significant, the pain is so intense.