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 china, While the overall prevalence of radiographic knee OA was similar to that demonstrated in the Beijing OA study, men in Wuchuan had about double the prevalence of severe radiographic [prevalence ratio (PR) 2.5, 95% CI 1.6 to 3.8] and symptomatic knee OA (PR 1.9, 95% CI 1.3 to 2.9).
Women in Wuchuan also had a higher prevalence of both severe radiographic (PR 1.4, 95% CI 1.0 to 2.0) and symptomatic knee OA (PR 1.6, 95% CI 1.2 to 2.1) compared with their Beijing counterparts. The prevalence of bilateral OA and lateral compartment disease were two to three times higher in both Chinese cohorts compared with estimates from the Framingham OA Study. According to a statistical analysis there are Extrapolated Incidence of Avascular Necrosis is 47751 in China.