What it means
Bone is living tissue that needs a steady blood supply. If that supply is blocked or damaged, an area of bone can die. Known causes include a fracture or dislocation, long-term steroid medicines, heavy alcohol use and some blood disorders, such as sickle cell disease, and sometimes no cause is found. MRI finds it early, often as a wavy line outlining the affected area, before X-rays show any change.
When it matters
Early AVN may cause no symptoms or only an ache. The concern is that dead bone under a joint surface can weaken and collapse over months to years, which can lead to arthritis. The size of the area and whether the surface has collapsed guide what happens next. Small areas without collapse are sometimes watched with repeat MRI. Because it often affects both hips, the other hip is usually checked too.
Questions to ask your doctor
- What stage is it, and has the bone surface collapsed at all?
- What might have caused it in my case?
- Should the other hip or other joints be checked as well?
