What is Bone Infarction & How is it Treated?
What is Bone Infarction?
Bone Infarction which is also known by the name of osteonecrosis or avascular necrosis is a pathological condition of the musculoskeletal system in which the bones in the body mainly the hips, shoulders, knees, and ankles start to die as a result of decreased blood flow to the joints of these bones resulting in complete breakdown of the bones.1 Under normal circumstances, new bone always keeps on replacing the old bones and this is a constant process. This keeps the bones strong and keeps the body stable musculoskeletally. With Bone Infarction, the breakdown of bones occurs at a faster rate than the rate with which it can be replaced by the new stronger bone causing the bones to become weak resulting in variety of symptoms and if appropriate treatment is not given to the affected individual then it may lead to complete breakdown of the bones and movement of the affected joint becomes very painful and difficult. Bone Infarction usually is seen in people in their 40s or 50s.
What Causes Bone Infarction?
As stated, Bone Infarction is caused due to decreased blood supply to the joints of the bone. The cause of this decreased supply is not clearly known as yet but there are certain factors which may lead to decreased blood supply to the joints of the bones causing Bone Infarction. These factors are:
- Excessive use of steroid medications
- Alcohol abuse 2
- Injury to the bone or joint
- Increased pressure within the bone.
Individuals who are undergoing radiation or chemotherapy for any form of cancer or have undergone an organ transplant like a kidney transplant are also at risk for developing Bone Infarction and hence Bone Infarction is seen in people suffering from cancer, lupus or HIV, vasculitis, osteoarthritis, osteoporosis, or certain blood disorders like sickle cell trait.
What are the Symptoms of Bone Infarction?
During the initial stages of Bone Infarction there are practically no symptoms to speak of. At maximum there may be some pain felt when putting some pressure on the joint but as the disease process gets worse the pain in the joint gets worse and it starts to become difficult to even move the joint. There may come a stage when the joint will pain even when the individual is at rest. With each passing day, the pain in the joint will start to worsen and as the bone and the joint start to break down the use of the joint becomes minimal. Citing an example, if there is Bone Infarction in the hips then ambulation will become extremely difficult for that individual.
How is Bone Infarction Diagnosed?
For diagnosing Bone Infarction, the doctor will take a detailed history of the patient inquiring as to when the symptoms started, were there any injuries to the joint in the recent past that may be causing the symptoms. A detailed physical examination will then be conducted to check for range of motion and stability of the affected joint. The doctor may also palpate the area to look for areas of tenderness. A range of motion check will also be done as a part of the physical examination to see if there is change in range of motion and to see if there is any reproduction of pain. Radiological studies in the form of x-rays, CT or MRI scan will also be done of the affected joint which will clearly show the areas of joint breakdown and thus confirm the diagnosis of Bone Infarction.3 Additionally a bone scan and a bone biopsy may be done to confirm the diagnosis of Bone Infarction.
How is Bone Infarction Treated?
The treatment for Bone Infarction is aimed at preventing the joints and bone from breaking down. If this condition is left untreated within a span of a couple of years, the patient will lose all use of the affected joint including mobility. In order to formulate the best possible treatment for the patient the doctor will first look for the age of the patient, the extent to which the disease has progressed, the extent of damage that has been done due to Bone Infarction, and the cause of the condition, if known. The main aim of treatment for Bone Infarction is:
- Make the joint usable
- Prevent further damage to the bone and joint.
For this both nonsurgical and surgical treatments will be tried depending on the stage of the disease process. To begin with, the doctor will start with nonsurgical approaches and if there is no improvement in the condition of the patient then surgery is the preferred route to go.
Nonsurgical Treatments for Bone Infarction: The nonsurgical treatments for Bone Infarction may help the patient for a short period of time but it does not cure the disease. The patient will first be prescribed NSAIDs in the form of Tylenol or ibuprofen to calm down the pain and swelling associated with bone infarction. For people who have clotting disorders blood thinners might be prescribed for prevention of blood clots which may block the supply of bone to the joint. The patient may also be prescribed cholesterol lowering medications in case if the patient gets this disease due to excessive use of steroids.
Another method used to treat Bone Infarction is to take as much weight off the affected joint as possible. If the bones affected are of the lower extremity or the hip then the doctor will recommend the patient to not be weight bearing on the extremity and to use supportive devices like a crutch to ambulate. This may allow the bone and the joint to heal. The patient will then be recommended to a physical therapist for range of motion and strengthening exercises to help increase range of motion of the affected joint.
If the above treatments are not found to be effective in reliving symptoms, then the doctor will take a surgical route for treatment of Bone Infarction. There are basically four types of surgical procedures done for treatment of Bone Infarction. These surgical procedures are:
- Core Decompression Surgery for Bone Infarction: This decompression surgery lowers the pressure built inside the bone and helps increase blood flow to the bone
- Osteotomy: This is a surgical procedure which helps reshape the bone so as to minimize stress on the damaged joint and thus prevent further damage to the joint and treat Bone Infarction
- Bone Grafting: In this procedure, healthy bone is taken from one part of the body and is replaced with the diseased bone. This allows the growth of new bones normally and thus treats Bone Infarction.