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 abuse
- 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
- Avascular Necrosis (Mayo Foundation for Medical Education and Research)
- Osteonecrosis (American College of Rheumatology)
- Osteonecrosis (Avascular Necrosis) (National Institute of Arthritis and Musculoskeletal and Skin Diseases)
- What Is Osteonecrosis? (National Institute of Arthritis and Musculoskeletal and Skin Diseases) Also in Spanish
Treatments and Therapies
- Bone Grafts: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
- Easing Joint Pain: Are NSAIDs Right for You? (Consumers Union of U.S.) - PDF Also in Spanish
- Hip Replacement (National Institute of Arthritis and Musculoskeletal and Skin Diseases) Also in Spanish
- What Is a Hip Replacement? (National Institute of Arthritis and Musculoskeletal and Skin Diseases)
- Genetics Home Reference: Legg-Calvé-Perthes disease (National Library of Medicine)