Information for Patients
Also called: Aseptic necrosis, Avascular necrosis, Ischemic necrosis
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
- Osteonecrosis (Medical Encyclopedia)
General Equivalence Map Definitions
The ICD-10 and ICD-9 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.
- Approximate Flag - The approximate flag is on, indicating that the relationship between the code in the source system and the code in the target system is an approximate equivalent.
- No Map Flag - The no map flag indicates that a code in the source system is not linked to any code in the target system.
- Combination Flag - The combination flag indicates that more than one code in the target system is required to satisfy the full equivalent meaning of a code in the source system.