Osteonecrosis is a disease caused by reduced blood flow to bones in the joints.
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.
Many cases of osteonecrosis do not have a known cause, so prevention may not be possible.
In some cases, you can reduce your risk by doing the following:
- Avoid drinking excessive amounts of alcohol.
- When possible, avoid high doses and long-term use of corticosteroids.
- Dive safely to avoid decompression sickness.
Osteonecrosis occurs when part of the bone does not get blood and dies. After a while, the bone can collapse. If osteonecrosis is not treated, the joint deteriorates, leading to severe arthritis.
Osteonecrosis can be caused by disease or by severe trauma, such as a fracture or dislocation, that affects the blood supply to the bone. Osteonecrosis can also occur without trauma or disease. This is called idiopathic -- meaning it occurs without any known cause.
The following are possible causes:
- Using oral or intravenous steroids
- Excessive alcohol use
- Sickle cell disease
- Radiation therapy
- Gaucher disease
- Decompression sickness from a lot of deep sea diving
- Dislocation or fractures around a joint
- Clotting disorders
- HIV or taking HIV drugs
When osteonecrosis occurs in the shoulder joint, it is usually due to long-term treatment with steroids or a history of trauma to the shoulder.
Legg-Calvé-Perthes disease is a similar condition seen in children and adolescents.
There are no symptoms in the early stages. As bone damage worsens, you may have the following symptoms:
- Pain in the joint that may increase over time and becomes severe if the bone collapses
- Pain that occurs even at rest
- Limited range of motion
- Groin pain, if the hip joint is affected
- Limping, if the condition occurs in or below the hip
Your health care provider will do a physical exam to find out if you have any diseases or conditions that may affect your bones. You will be asked about your symptoms and medical history.
Be sure to let your provider know about any medicines or vitamin supplements you are taking, even over-the-counter medicine.
After the exam, your provider will order one or more of the following tests:
- Bone scan
- CT scan
If your provider knows the cause of osteonecrosis, part of the treatment will be aimed at the underlying condition. For example, if a blood clotting disorder is the cause, treatment will consist, in part, of clot-dissolving medicine.
If the condition is caught early, you will take pain relievers and limit use of the affected area. This may include using crutches if your hip, knee, or ankle is affected. You may need to do range-of-motion exercises. Nonsurgical treatment can often slow the progression of osteonecrosis, but most people will need surgery.
Surgical options include:
- A bone graft
- A bone graft along with its blood supply (vascularized bone graft)
- Cutting the bone and changing its alignment to relieve stress on the bone or joint (osteotomy)
- Total joint replacement
- Removing part of the inside of the bone (core decompression) to relieve pressure and allow new blood vessels to form