Introduction of Avascular Necrosis in Bone
Avascular necrosis of bone (osteonecrosis, aseptic necrosis, osteochondritis dissecans) is death of bone tissue due to failure of the blood supply. Avascular necrosis is very common in people between the ages of 30 and 60 years. The disease is very often affects the thigh bone (femur) at the hip (the front of the femur). Often, both hips affected.
In people over 50 years old, usually caused by avascular necrosis of hip fractures but may be caused by diseases that block small blood vessels that supply until the end of long bones. For example, a compound made up of fatty emboli may obstruct blood vessels in people with liver become smaller which caused by alcohol. Femur at the knee are also commonly affected; arm bone in the shoulder is sometimes affected.
Doctors classify avascular necrosis according to whether or not caused by injury. Only the serious injuries that can cause interference; small cuts can not be. In general, fracture or dislocation, in which the blood vessels to the portion of bone is torn or physical injury, is a type of injury that can lead to avascular necrosis.
Cause of Avascular Necrosis in Bone
The cause of nontraumatic such as alcohol abuse, the use of high doses of corticosteroids (especially used in the long term), decompression sickness (which happens to divers who ascend to the surface too quickly), and sickle cell disease. Rarely, Gaucher disease, tumors (eg, lymphoma), and radiation therapy can cause avascular necrosis. Certain blood clotting disorders can also cause. In about 25% of patients, the cause is unknown.
Avascular necrosis knee can occur spontaneously, especially in women older than 55 years who do not have risk factors for the disorder. Some experts disagree whether spontaneous avascular necrosis knee avascular necrosis is really a disorder or another unknown.
Symptoms of Avascular Necrosis in Bone
In some people, severe pain down into helplessness as sudden – this person is often able to remember the exact day and hour when the pain began to emerge. Sudden arrival of this pain may occur when the blood supply is stopped. However, most people have avascular necrosis for some time before symptoms appear. The pain occurs when the bone to die finally broke. Caused such pain when standing, walking, or moving the affected bone and generally gets better when people rest.
In avascular necrosis hip, groin pain may extend the front and inside of the thigh or felt in the buttocks. People limp, try reducing all motion thighs. As the disorder progresses, the more likely a small hip fracture occurs and eventually decreases bone. The pain is also increasing, and thigh joints feeling stiff and lose some kind of movement.
Avascular necrosis knees often appear suddenly as severe pain constantly and slowly, usually g part of the knee. Approximately one third of patients, the knee joint swelling due to excess fluid. Avascular necrosis shoulder may result in mild or transient symptoms and may be barely visible. People typically reduces shoulder movements to avoid pain.
Diagnosis Avascular Necrosis in Bone
Because of avascular necrosis is often painless at first, often not diagnosed in the early stages. When avascular necrosis occurs due to a serious injury, interference can not be known by microscopy for days to weeks and can not be identified by X-ray until several months later.
Magnetic resonance imaging (MRI) is the best test to determine early avascular necrosis, so that complications (such as shrinking the front of the thigh bone) could be avoided. X-ray or CT scan is used to decide whether the bones are smaller, how to follow up interference, and whether the patient has osteoarthritis which associated with an affected joint.
Treatment of Avascular Necrosis in Bone
Simple treatments include the use of nonsteroidal anti-inflammatory drugs (NSAIDs) or other analgesics for pain and avoid carrying heavy loads or stretching the affected bones and joints. Often, this treatment should be carried out for 6 months or more. Exercise to increase the useful range of joint movement. However, this treatment is rarely adequate when done alone and do not eliminate the interference.
The simplest surgical procedure called core decompression, which involves taking a plug of bone from the affected areas. This procedure is very effective for early disease who have not developed in the direction of smaller bones; action even prevent become smaller. Core decompression may also be used for someone with less than 50 years of age whose bones had shrunk; treatment may delay the need for total joint replacement for a few years due to reduced patient pain or heal. The procedure takes less than an hour. People have to be on crutches for 4 to 6 weeks.
Another bone grafting procedures. For avascular necrosis in the hip, consisting of bone grafting tissue sampling bone with intact blood vessels from elsewhere in the body and connects the bone tissue and blood vessels near the hip. Grafts serve as infrastructure for the body to form new bone; however, that the surgery is successful, the body is forced to form a new blood supply. This surgery requires several hours. People have to spend a few months on crutches afterward.
If the core decompression or bone grafting performed before the bone shrinks, can help to prevent joint damage, especially if exposed to the hip or knee. Surgery is rarely needed when the initial shoulder was not affected due to shoulder the burden and often heal without surgery.
Procedures where bone cut (osteotomy as mentioned) is used to delay the need for joint replacement in people with age less than 50 years, the people who are already experiencing bone reduction. People who undergo an osteotomy is not eligible for core decompression or bone grafting because too many downsizing occurs. Typically, the location of avascular necrosis in the area of weight-bearing bone. In some cases, bone may be cut below the affected field and played or directed to some of the bones were not involved could be a new load-bearing area.
Total joint replacement is the only effective procedure when avascular necrosis is caused significant osteoarthritis joint on the other side. Although the success rate for this procedure is higher than 95%, physicians should carefully determine the decision recommends joint replacement for artificial joints do not last for ever, and the young people may have to be replaced at a later time. Therefore, for some of the younger people, many surgeons use a procedure called resurfasi the base of the femur when hip joint cavity is not exposed.
This procedure involves planting base metal cover behind the thigh bone (similar to the tooth cap than pulling teeth and dentures put). Several people undergo resurfacing procedure followed the base of the femur with total hip replacement.