Avascular necrosis is a condition of decreased blood supply resulting in the death of bone tissue. This is also known as osteonecrosis. Avascular necrosis usually leads to the tiny breaks in the bone forcing the bone to collapse eventually. The blood supply to a section of bone also gets interrupted in case of fractured or dislocated joints. Know the types, causes, symptoms, treatment, surgery and epidemiology of Avascular necrosis or osteonecrosis.