What is avascular necrosis?
Avascular necrosis occurs due to a lack of blood flow to the bone. As a result, bone cells die and deteriorate, causing pain and inflammation in the joints. You may develop avascular necrosis in one or more of your bones. This disease often spreads in the upper part of the femur (thigh bone). Other common sites include the upper arm, knee, shoulder, and ankle. It can affect men and women at any age, but it most often occurs in the thirties, forties, or fifties.
What causes avascular necrosis?
There are several causes of avascular necrosis. One cause is any disease that leads to reduced blood supply to the femur, resulting in avascular necrosis. Injuries to the femur and fractures of the femoral neck can damage blood vessels. Dislocation of the hip joint can tear blood vessels. Taking corticosteroids such as prednisone or methylprednisolone is one of the most common medication-related causes of avascular necrosis. Smoking narrows blood vessels, thus reducing blood flow to the hip area. Excessive alcohol consumption damages blood vessels and leads to avascular necrosis. Certain groups, such as deep-sea divers and miners exposed to air pressure changes, are at high risk for blood vessel damage. There is a long list of other diseases associated with avascular necrosis of the femoral head, including leukemia, sickle cell disease, and HIV infection.
Which joints are affected by avascular necrosis?
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Joints most susceptible to avascular necrosis: hip, knee, and shoulder.
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Joints less susceptible to avascular necrosis: ankle, feet and hands, jaw, spine, and wrist.
How is avascular necrosis diagnosed?
If avascular necrosis is suspected, your doctor may ask you to undergo one or more of the following tests: X-ray, magnetic resonance imaging (MRI), bone scan, computed tomography (CT scan), or biopsy (tissue examination) in rare cases.
What are the treatment options for avascular necrosis?
(A) Non-surgical treatments: Safe weight-bearing aids such as a cane, crutches, or a walker can help relieve pain caused by avascular necrosis.
(B) Medication therapy: There are no specific medications to prevent or treat avascular necrosis.
(C) Surgical treatment:
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Core decompression: A surgical procedure that involves placing a bone graft outside the painful area. This helps reduce pain but only for cases that have not progressed to an advanced stage.
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Bone grafting: Used when part of the bone has died but has not healed spontaneously. One method is to surgically remove the dead bone and fill the void with a bone graft taken from another part of the patient’s body or from a bone bank.
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Osteotomy: Avascular necrosis often occurs in weight-bearing bones. In some cases, the bone below the affected area is cut and reshaped to allow new bone to grow.
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Resurfacing of the femoral head: This involves placing a metal hemisphere over the femoral head that matches the original size of the femoral head.
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Femoral head replacement: This procedure involves complete replacement of the hip hemiarthroplasty.
How can I prevent avascular necrosis?
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To avoid avascular necrosis caused by corticosteroid medications, doctors only use such drugs when necessary, prescribe the lowest effective doses, and limit the duration of use.
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To prevent avascular necrosis resulting from decompression sickness, people working under pressure in high-pressure environments should follow proper decompression procedures in daily life.
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Avoid excessive alcohol consumption and smoking.
