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. "During a study in france, The distribution of osteoarthritis patients by occupation was compared with the distribution of occupations in all workers in France to obtain prevalence rate ratios.
Occupations with the greatest prevalence rate ratio were female cleaners (6.2; 95% CI 4.6 to 8.0), women in the clothing industry (5.0; 95% CI 3.9 to 6.3), male masons and other construction workers (2.9; 95% CI 2.6 to 3.3), and agriculture male and female workers (2.8; 95% CI 2.5 to 3.2). A twofold greater prevalence rate was observed within certain occupations between self-employed and salaried workers. Early onset of osteoarthritis was seen in the more heavy labour jobs with almost 40% of patients reporting their first symptoms before the age of 50. According to a statistical analysis there are Extrapolated Incidence of Avascular Necrosis is 2221 in France."