Conditions and symptoms
What Is Osteonecrosis? Jaw and Hip Bone Warnings Explained
Osteonecrosis · say it: OS-tee-oh-neh-KROH-sisAlso written: avascular necrosis, AVN, bone death, osteonecrosis of the jaw, ONJ
Short answer
Osteonecrosis means an area of bone has died because it lost its blood supply; labels often mention it in the jaw or hip.
What it means
Osteonecrosis means 'bone death'. It happens when part of a bone loses its blood supply, so the bone tissue in that area dies and may weaken or collapse. It most often affects the hip, but can affect other joints. Osteonecrosis of the jaw (ONJ) is a specific form where an area of jawbone becomes exposed in the mouth and does not heal.
Labels mention osteonecrosis because some medicines are linked to it. Long courses of corticosteroids are linked to hip osteonecrosis, and bisphosphonates and some other bone medicines are linked to rare jaw osteonecrosis, often after dental work such as tooth extraction. That is why labels suggest good dental care and telling your dentist about these medicines.
It is different from osteoporosis, which is thinning of bone across the skeleton. Osteonecrosis affects a specific area of bone where the blood supply is lost.
Where you may see it
- Bisphosphonate and other bone medicine labels under 'Osteonecrosis of the jaw'
- Corticosteroid leaflets
- MRI or X-ray reports of the hip
📄 How it looks on a report
Osteonecrosis of the jaw has been reported. Consider a dental examination before starting treatment.
🙅 What it does not mean
- A label warning does not mean it is likely; jaw osteonecrosis is rare.
- It is not the same as osteoporosis.
- Having dental treatment while on these medicines is not forbidden; your dentist and doctor can plan it together.
🗒️ Questions to ask your doctor
💊 Medicines whose labels mention “Osteonecrosis”
Plain-English explanations of each medicine, from its official FDA label.
- Alendronate
a bisphosphonate, a medicine that slows the breakdown of bone by blocking cells called osteoclasts
🔗 Read more from trusted sources
- “Osteonecrosis” on MedlinePlus ↗
US National Library of Medicine
- NCI Dictionary definition ↗
US National Cancer Institute: “osteonecrosis”
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