Avascular necrosis is the death of bone tissue due to a lack of blood supply. Also called osteonecrosis, avascular necrosis can lead to tiny breaks in the bone and the bone's eventual collapse. The blood flow to a section of bone can be interrupted if the bone is fractured or the joint becomes dislocated. Avascular necrosis typically causes no symptoms; however, as the disease progresses it becomes painful. At first, you may experience pain when you put pressure on the affected bone. Then, pain may become more constant.
If the disease progresses and the bone and surrounding joint collapse, you may experience severe pain that interferes with your ability to use your joint. The time between the first symptoms and collapse of the bone may range from several months to more than a year. If avascular necrosis is caught early, treatment may involve taking medications to relieve pain or limiting the use of the affected area. If your hip, knee, or ankle is affected, crutches may be necessary to take weight off the damaged joint.
Your doctor may also recommend range of motion exercises to help keep the affected joint mobile. It is also associated with Osteoarthritis and Knee injuries. In Canada, based on self-reported health professional diagnosed arthritis, the crude prevalence from the National Population Health Survey (NPHS) and Canadian Community Health Survey (CCHS) was 13.4% in 1994, 14.5% in 1996, 16.0% in 1998 and 2000, and 17.6% in 2002 .
The national prevalence in the 1991 General Social Survey (GSS) was at 20.8%. In 2000-2001, data from 286 regions across Canada revealed a prevalence of arthritis of 16.0%, with significant differences across regions (p<0.001), ranging from 12.0% in Quebec to 23.3% in Nova Scotia. According to a statistical analysis there are Extrapolated Incidence of Avascular Necrosis is 1195 in canada.