Avascular Necrosis

Avascular necrosis (AVN), also known as osteonecrosis, of the hip describes a process of bone death in the head of the femur due to a disruption in the blood supply to this region. There are multiple causes for this disruption, but all lead to some amount of bone death that can cause large portions of the femoral head to collapse. If a substantial enough portion is involved, the head may become misshapen and contribute to further problems, including hip arthritis.