Blood carries necessary components like nutrients and oxygen to bones for them to stay healthy and to be regenerated. Avascular necrosis or osteonecrosis occurs when bone tissue dies from a temporary or permanent shortage of blood supply. This can cause small fractures in the bone and can lead to bone collapsing. When a bone is broken or a joint is dislocated, the blood supply to a portion of the bone is disrupted. If a patient has been taking a high-dose of steroid medications and an extensive amount of alcohol for a long period of time, avascular necrosis could develop. The disease can occur in anybody, although the condition is most likely to occur in adults between 30 and 50 years old. If the condition appears near a joint, the surface around the area may break. It may impact one bone or multiple bones at a time.
In the beginning stage of avascular necrosis, symptoms do not tend to appear. As the illness progresses, the joints that are affected will be painful when they are being pressured. Patients will experience pain overtime even when they are lying flat. The level of pain ranges from mild to severe and it gradually increases. Pain that arises from avascular necrosis of the hip may start in the groin, buttocks or thigh areas. In addition to hip, shoulder, knee, hand and foot are the parts that can be affected.
Disruption of blood flow to bones is the primary cause of avascular necrosis. Shortage of blood supply can be caused by following reasons:
However, the cause of disrupted blood supply is unknown in around 25 percent of the patients who suffer from avascular necrosis.
Several medical conditions can also lead to avascular necrosis such as pancreatitis, diabetes, Gaucher’s disease, HIV, systemic lupus erythematosus, and sickle cell anemia.