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 Sweden, it was reported that individuals with knee OA have close to twofold increased risk of sick leave and about 40-50% increased risk of disability pension compared to the general population.
It is unknown whether similar figures can be found in Norway. The costs of OA care will be heavily influenced by the trends in OA occurrence, the severity of the disease, and the consequences of OA in function and work ability. More research is warranted on utilisation of self-management and treatment in primary, secondary, or tertiary care. According to a statistical analysis there are Extrapolated Incidence of Avascular Necrosis is 330 in Sweden."