Medically Reviewed by Dr Wang Lushun Exactly what is Avascular Necrosis (AVN)? Avascular necrosis, often called osteonecrosis, happens when the blood source to bone cells is disrupted, bringing about the death of bone tissue. It normally targets the hip joint, specifically the femoral head–the higher “ball” portion of the femur https://www.theorthopaedicandpainpractice.com/what-is-avascular-necrosis-of-the-hip/?_gl=1*xbbxlb*_up*MQ..&gclid=Cj0KCQjwkt6aBhDKARIsAAyeLJ2krYJSOuy5mZksrNqH-VDjQwW1ScD49yD8BUWysDG6u6bJPCSbXVUaAuCPEALw_wcB