Avascular necrosis
Also called: osteonecrosis
What it means
Avascular necrosis is when part of a bone dies because it loses its blood supply, which can weaken and eventually collapse that section of bone.
Knowing this condition exists helps you understand why certain bone-related symptoms or rare medication side effects are worth discussing with your doctor.
Avascular necrosis means a section of bone has lost its blood supply and the bone tissue in that area dies. Without blood flow, the bone can't maintain itself or heal normally, and it can weaken and eventually collapse. It's different from osteoporosis, which involves bones gradually losing density throughout the skeleton — avascular necrosis is more localized damage tied to circulation.
You may also hear the term osteonecrosis of the jaw, which is a specific, rare form of this problem linked mainly to long-duration use of certain osteoporosis medications called bisphosphonates. This is one of the uncommon tradeoffs discussed with these drugs, alongside atypical femoral fracture, and it's worth knowing about even though it's rare. Any questions about medication risks, benefits, or whether a change makes sense should go to your prescriber, since they know your full history.
Avascular necrosis sits alongside other distinct bone disorders like Paget's disease, osteogenesis imperfecta, and osteomalacia — each disrupts normal bone remodeling in its own way, whether through disorganized rebuilding, fragile collagen, soft bone from vitamin D deficiency, or in this case, bone death from lost circulation.
How sure is this?
Graded Established Science: Supported by broad scientific consensus and decades of research. Read each study with its grade in mind. One study is a piece of the picture, not the whole of it.
Where the Academy teaches it
This page is the short version. The lessons teach it in full, with the context around it and a quiz to lock it in.
Related words
Osteonecrosis of the jaw (ONJ) is a rare condition where part of the jawbone loses blood supply and fails to heal,…
An atypical femoral fracture is an uncommon break in the shaft of the thigh bone that looks and behaves differently…
Paget's disease is a condition where bone remodeling speeds up too much in specific spots, creating new bone that's…
Osteogenesis imperfecta is a genetic disorder that causes the body to make fragile collagen, leading to bones that…
Osteomalacia is softening of the bones caused by severe, long-term vitamin D deficiency, which prevents bone from…
Bisphosphonates are osteoporosis medications — like alendronate, risedronate, and zoledronic acid — that slow down…
Education only, not medical advice. Decisions about tests, medications and treatment belong with your own doctor. OsteoStrong does not diagnose, treat or cure any disease.
