Fat embolism as a cause of idiopathic necrosis of the head of the femur. Review of forty five cases of post traumatic fat embolism.

It has been postulated in recent years that idiopathic necrosis of the head of the femur may possibly be caused by arteriolar obstruction by fat emboli emanating from a fatty liver, which would act as a reservoir, due to various causes such as alcoholism and prolonged steroid therapy. A similar situation has been found in human pathology in post traumatic fat embolism. The writers have reviewed forty five cases of post traumatic fat embolism which had passed the pulmonary filter. All the cases were reviewed after a minimum of two years, since this is considered the minimum time within which necrosis can manifest itself radiologically. In none of these cases was there any evidence of necrosis of the head of the femur. These findings, supported by other critical considerations. do not lend support to the theory of fat embolism as a case of idiopathic bone necrosis.