It is widely believed that Perthes is caused by idiopathic avascular necrosis of the femoral head. That is, arising spontaneously from an idiopathic (unknown) cause, the top section of the femur ...

Pediatric orthopedists take special care to avoid a condition called avascular necrosis (also known as AVN or osteonecrosis), in which the bones of the hip joint do not receive enough blood. This can ...