Is avascular necrosis serious?

Very: Other than trauma/ fractures, most common cause of need for hip replacent.

Yes: Avascular necrosis is bone death due to lack of blood supply. This can occur in joints where the blood supply can be easily disrupted by injury or disease. Joints such as the hip, knee, wrist, elbow or ankle. Some medications such as steroids can increase risk of this problem. Disease which have increased risk include diabetes, sickle cell disease, gout, atherosclerosis.