Aseptic Necrosis of the Hip
(Osteonecrosis, Avascular Necrosis, Ischemic Necrosis, Osteochondritis Dessicans)
Aseptic necrosis of the hip is the death of bone tissue in the head of the femur due to an inadequate blood supply.
Certain bones have a fragile blood supply. The head of the femur in the hip joint is the most likely to suffer loss of blood supply and consequent tissue death. Unidentified and uncorrected it will progress to deformity, causing pain and a limp.
Any event or condition that damages the arteries that feed the head of the femur raises the risk of aseptic necrosis. The most common events are fractures in the upper femur and dislocations of the hip. Other causes reduce the blood supply by occluding or compressing the blood vessels.
There is a specific type of aseptic necrosis of the hip called Legg-Calvé-Perthes disease that affects the growth plate at the upper end of the femur in children, most commonly boys age 5-10 years old.
The following factors increase your chances of developing aseptic necrosis of the hip. If you have or have had any of these risk factors, tell your doctor:
- Femoral neck fractures
- Dislocation of the hip
- Radiation therapy
- Prolonged or repeated use of cortisone-like drugs
- Decompression sickness
- Sickle cell disease
- Gaucher’s disease
The few symptoms of aseptic necrosis of the hip are nonspecific and may be caused by other, less serious health conditions. If you experience one of them and are at risk for aseptic necrosis of the hip, see your physician.
- Hip pain
- Knee pain (pain in the hip is sometimes “referred” to the knee.)
Your doctor will ask about your symptoms and medical history, and perform a physical exam. If the diagnosis is suspected you will be referred to an orthopedic surgeon.
Tests may include the following:
- X-ray–a test that uses radiation to take a picture of structures inside the body, especially bones
- When the disease is seen on an x-ray it is usually too advanced to reverse with treatment.
- CT Scan–a type of x-ray that uses a computer to take pictures of structures inside the body
- Radioisotope Bone Scan
- A bone scan is quite sensitive but nonspecific.
- MRI Scan–a test that uses magnetic waves to make pictures of structures inside the body
- An MRI scan is the most useful test and can detect the condition early enough to begin effective treatment.
Talk with your doctor about the best treatment plan for you. Treatment options include the following:
Taking over-the-counter pain relievers and performing nonweight bearing exercise when healing from hip damage may prevent or minimize disease progression.
There are several surgical procedures used to treat aseptic necrosis of the hip. The choice depends upon the extent of disease and the age and health status of the patient. Bone grafts, decompression of the inside of the bone, realignment of the bone, and prosthetic hip replacement are all available.
To help reduce your chances of getting aseptic necrosis of the hip, take the following steps:
- Minimize the dose and duration of cortisone-like drugs
- Avoid decompression disease when diving underwater