What is avascular necrosis?
When the blood supply to the bone tissue decreases or is completely cut off, the tissue starts to degenerate and ultimately dies. This is called avascular necrosis or osteonecrosis. Death of bone tissues may cause tiny cracks or breaks in the bones and eventually lead it to collapse completely. The hip joint is one of the most commonly affected regions in the body.
How does it happen?
The blood flow to a section of the bone can be interrupted if the bone is fractured or the joint is dislocated. Cancer treatments that involve radiation can also weaken bones and harm blood vessels. Excessive alcohol intake or long term use of high-dose steroid medications can also cause avascular necrosis. Some medical conditions, such as sickle cell anaemia or Gaucher’s disease, can increase the pressure inside the bone, making it more difficult for fresh blood to enter it. While it can happen to anyone, it is more commonly seen in men between the ages of 30 to 60 years.
A person’s risk of developing avascular necrosis may be alleviated by certin diseases, medical treatments or personal habits.
Excessive drinking – Too much alcohol consumption may build up fatty deposits in your blood vessels which can restrict blood flow to the bones.
Medication – Steroids such as corticosteroids that are taken at high doses and for a long period of time can increase the amount of fat in the blood, causing blockage of blood vessels. Biphosphonates, used to treat osteoporosis, can sometimes lead to osteonecrosis when used in high doses.
Medical conditions and procedures – Some medical conditions such as HIV/AIDS, lupus, diabetes, sickle cell anaemia and procedures such as radiation therapy, dialysis and kidney or other organ transplants can predispose one to the risk of avascular necrosis.
Signs and Symptoms of the disease
Usually, no clear symptoms are visible in the early stages of avascular necrosis of the bone. However, as the disease progresses, the patient may experience pain in the affected joints, especially when you put weight on it. As the disease worsens, the joint may hurt even when the patient is not moving or simply lying down.
The joints that are most likely to be affected are the hips, shoulders, knees, hands and feet. Usually the pain will start off being mild but may develop into a severe ache with time. The pain associated with avascular necrosis of the hips may be focused in the groin, thigh or buttock. Some can experience pain and avascular necrosis in either one side or both.
If you are experiencing persistent pain in any of your joints, you should see a doctor about it. If you believe you might have a broken bone or a dislocated joint, even though you have not experienced any force trauma, you should immediately seek medical attention. If left untreated, the pain will only worsen with time and eventually the bone may collapse. If the bone becomes distorted, it may cause severe arthritis.