Avascular necrosis of the femoral head?,”The well-known causes of non-traumatic avascular (aseptic) necrosis are chronic corticosteroid therapy (eg, prednisone), alcoholism
and hemoglobinopathies. It usually presents as progressive hip or groin pain without restriction of motion range and normal radiography on early stages. MRI is gold standard for the diagnosis of avascular necrosis of the hip.”