Before we begin: Osteonecrosis (Avascular Necrosis) is marked by a loss of blood supply to the bones, causing bone to break down faster than the body make new bone.
This tutorial walks you through everything you need to know about osteonecrosis. We explain it in plain language, step by step, so whether you are a student, a patient, or simply curious, you will come away with a solid understanding.
We cover what it is, why it matters, how it is diagnosed, and what you can do about it. Key facts are called out along the way.
Osteonecrosis is a disease caused by reduced blood flow to bones in the joints. In people with healthy bones, new bone is always replacing old bone. In osteonecrosis, the lack of blood causes the bone to break down faster than the body can make enough new bone. The bone starts to die and may break down.
You can have osteonecrosis in one or several bones. It is most common in the upper leg. Other common sites are your upper arm and your knees, shoulders and ankles. The disease can affect men and women of any age, but it usually strikes in your thirties, forties or fifties.
At first, you might not have any symptoms. As the disease gets worse, you will probably have joint pain that becomes more severe. You may not be able to bend or move the affected joint very well.
No one is sure what causes the disease. Risk factors include :
Long-term steroid treatment
Alcohol misuse
Joint injuries
Having certain diseases, including arthritis and cancer
Doctors use imaging tests and other tests to diagnose osteonecrosis. Treatments include medicines, using crutches, limiting activities that put weight on the affected joints, electrical stimulation and surgery.
NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases
Also known as: Aseptic necrosis, Avascular necrosis, Ischemic necrosis.
Related topics: Aseptic Necrosis, Avascular Necrosis, Legg-Calve-Perthes Disease.
Categories: Bones, Joints and Muscles.
Source: National Institutes of Health — National Institute of Arthritis and Musculoskeletal and Skin Diseases.
Key Takeaways
Understanding osteonecrosis is an important part of taking charge of your health. Here is what to remember:
- Know the signs — Recognizing early symptoms can lead to earlier diagnosis and better outcomes.
- Talk to your provider — If you have concerns or a family history of this condition, bring it up at your next checkup.
- Stay informed — Medical knowledge evolves. Keep learning and asking questions.
- You are not alone — Many people deal with this condition. Support groups and educational resources can help.