Hip osteonecrosis, also known as avascular necrosis of the hip, is caused by disruption of the blood supply to the femoral head (ball) in the hip joint. The bone in the hip joint is constantly regenerating itself and if the bone cells lose their blood supply then bone and joint destruction may occur and lead to severe pain and arthritis in the joint.
Who is at risk for this?
Osteonecrosis has multiple potential identified risk factors including:
› Prior hip trauma (dislocation, fracture)
› Excessive alcohol use
› History of use of oral corticosteroid medicines
› Medical conditions such as Caisson disease (diver’s disease or “the bends”), sickle cell disease, myeloproliferative disorders, Gaucher’s disease, systemic lupus erythematosus, Crohn’s disease, arterial embolism, thrombosis, and vasculitis.
Even if you do not have any of the risk factors listed above, you can still develop osteonecrosis.
Osteonecrosis is a slowly developing disease (sometimes over years) that can present in different stages (see cartoon image). You may experience one or more of these common symptoms:
› Pain and stiffness in the joints
› Swelling in one or more joints
› Continuing or recurring pain or tenderness in a joint
› Difficulty using or moving a joint in a normal manner
› Warmth and redness in a joint
› Dull, aching pain in the groin, outer thigh or buttocks
› Pain that is worse in the morning and lessens with activity
› Increased pain and stiffness with vigorous activity › Pain that limits your movements or makes walking difficult
The four stages of osteonecrosis. The disease can progress from a normal, healthy hip (Stage I) to the collapse of the femoral head and severe osteoarthritis (Stage IV).
How is hip osteonecrosis diagnosed?
Dr. Danoff will start by asking you a series of questions to better understand your current bone and joint health and your history pertaining to your hip condition. In addition to a medical history, a thorough physical evaluation will be performed, during which he will assess your walking, range of motion, and strength around the hip. X-rays are important part of your evaluation to look at the status of your hip joint. MRI is also useful to stage the disease and provide a prognosis.
How is hip osteonecrosis treated?
Osteonecrosis is a progressive disease that often requires surgical intervention to prevent the progression of disease or to treat the pain. The hip joint can be potentially preserved if the disease is diagnosed and treated in early stages.
There are several different surgical procedures used to treat osteonecrosis of the hip.
This procedure involves drilling one larger hole or several smaller holes into the femoral head to relieve pressure in the bone and create channels for new blood vessels to nourish the affected areas of the hip.
Core decompression may prevent osteonecrosis from progressing to severe arthritis and the need for hip replacement in some cases. This depends upon the stage and size of the osteonecrosis at the time of the procedure. It takes a few months for the bone to heal and, during this time, you will need to use a walker or crutches to avoid putting stress on the damaged bone.
When osteonecrosis is diagnosed after collapse of the bone of the femoral head, core decompression is not usually successful in preventing further collapse. In this situation, the patient is best treated with a total hip replacement.
In this case Dr. Danoff may recommend a total hip replacement. In this procedure, the hip joint is completely replaced with a new socket (acetabulum) and ball (femoral head).
If you would like to know more about hip replacement surgery CLICK HERE