Avascular Necrosis. This is a painful disease manifesting in the larger joints of the body. There is bone death under the articulation of these joints. Eventually a small crescent size of bone death can become larger and the actual joint will collapse into the dead and infacted tissue underneath. There is no cure. It started for me as a result of prolonged use of prednisone. Joint replacement is the go to solution. Other treatments like core decompressionnd stem cells may work by staving of the disease and increasing new blood vessel supply.