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.
According to a study in finland, The age-adjusted prevalence of knee pain during the past month was 18.1% in men and 21.0% in women. The prevalence increased with age in both genders. According to a statistical analysis there are Extrapolated Incidence of Avascular Necrosis is 191 in Finland. However, the increase was not linear: it was steeper after 55 years of age. In men the highest prevalence (36.5%) was observed in the 85 years or over age group, whereas in women the highest prevalence (42.0%) was found in those aged 75–84 years. The prevalence of knee pain was significantly related to years of education in both genders.