Avascular Necrosis of the Hip

Avascular Necrosis

Avascular necrosis of the hip seems to be an ever increasing reason for early total hip replacement. It affects younger individuals with a genetic predisposition to avascular necrosis, who have an environmental stimulus that sets off the process. We know that longer term use of steroid medications like “cortisone” preparations can lean to avascular necrosis of the hip.

Avascular necrosis of the hip looks like a "dark" spot on hip MRI. It is dead bone.
Avascular necrosis of the hip looks like a “dark” spot on hip MRI. It is dead bone.

 

Once the dead bone begins to collapse or crumple within the femoral head, total hip replacement is usually necessary. There are other treatments available, but they have a poor success rate with avascular necrosis with cartilage collapse.  Since our results with cementless hip replacement are very good now, we do not hesitate as much as we used do before doing a hip replacement in a younger individual. Other factors associated with avascular necrosis are overuse of alcoholic beverages in susceptible individuals. The mechanism is though to be an abnormality of fat and lipid metabolism in the presence of alcohol which leads to clotting up of small arterioles in the femoral head.