Avascular Necrosis (Osteonecrosis)
Avascular necrosis (AVN), also called osteonecrosis, aseptic necrosis, or ischemic bone necrosis, is a condition that occurs when there is loss of blood to the bone, eventually causes the bone to collapse.
Who Gets Avascular Necrosis and What Causes It?
- Dislocation or fracture of the thigh bone (femur). This type of injury can affect the blood supply to the bone, leading to trauma-related avascular necrosis.
- Chronic corticosteroid use. Long-term use of these inflammation-fighting drugs, either orally or intravenously.
- Excessive alcohol use.
- Blood clots, inflammation, and damage to the arteries
Other conditions associated with nontraumatic AVN include:
- Gaucher’s disease an inherited metabolic disorder in which harmful quantities of a fatty substance accumulate in the organs
- Sickle cell disease
- Pancreatis inflammation of the pancreas
- HIV infections
- Radiation Therapy and chemotherapy
- Autoimmune disease.
- ecompression sickness, a condition that occurs when the body is subjected to a sudden reduction in surrounding pressure, causing the formation of gas bubbles in the blood
Symptoms of Avascular Necrosis
In its early stages, AVN typically cause no symptoms; however, as the disease progresses it becomes painful. At first, pain is felt while walking. Then, pain may become more constant. If the disease progresses and the bone and surrounding joint collapse, one may experience severe pain that interferes with ability to use your joint. The time between the first symptoms and collapse of the bone may range from several months to more than a year.
Treatment for Avascular Necrosis
The goals of treatment for AVN are to improve or ensure function of the affected joint, stop the progression of bone damage, and reduce pain.
The best treatment will depend on a number of factors, including:
- Stage of the disease
- Location and amount of bone damage
- Cause of AVN
If the cause of avascular necrosis is identified, treatment will include efforts to manage the underlying condition. For example, if AVN is caused by blood clots, a medication to dissolve clots is used. If inflammation of the arteries is responsible, anti-inflammatory medicines are used.
If avascular necrosis is caught early, treatment may involve taking medications to relieve pain or limiting the use of the affected area. If hip, knee, or ankle is affected, crutches may be necessary to take weight off the damaged joint. Range-of-motion exercises to help keep the affected joint mobile.
While these nonsurgical treatments may slow the progression of avascular necrosis, most people with the condition eventually need surgery.
Surgical options include:
- Bone grafts, which involve removing healthy bone from one part of the body and using it to replace the damaged bone
- Osteotomy, a procedure that involves cutting the bone and changing its alignment to relieve stress on the bone or joint
- Total joint replacement, which involves removing the damaged joint and replacing it with a synthetic joint
- Core decompression, a procedure that involves removing part of the inside of the bone to relieve pressure and allow new blood vessels to form
- Vascularized bone graft a procedure that uses the patient's own tissue to rebuild diseased or damaged hip joints; the surgeon first removes the bone with the poor blood supply from the hip and then replaces it with the blood-vessel-rich bone from another site, such as the fibula, the smaller bone located in the lower leg.