Causes of avascular necrosis
By the development of avascular necrosis of the headthe femur can cause a variety of factors. Virtually any reason, contributing to a breach of the blood flow in the arteries of the femoral head can be the impetus for the development of avascular necrosis. So traumatic hip injuries can lead to disruption of the blood supply to the femoral head as a result of mechanical failure or arterial thrombosis. The most common injuries that lead to the development of avascular necrosis are hip fracture and hip dislocation. Aseptic necrosis develops after a few months, although the first clinical symptoms usually appear in patients much later (often in 1.5-2 years after the trauma).
Acceptance of some drugs can alsopromote the development of avascular necrosis. Most often aseptic necrosis develops in the long-term use of high doses of glucocorticoids for severe rheumatic diseases, asthma and others. It has been shown that treatment with short courses of hormonal therapy does not increase the risk of avascular necrosis of the femoral head. It is safe in this respect, a one- or two-fold intraarticular or periarticular administration of hormonal preparations for the treatment of osteoarthritis, bursitis, tendonitis and other inflammatory diseases of the musculoskeletal system. We trace a clear relationship between excessive alcohol intake and the incidence of avascular necrosis. Alcohol contributes to the damage of blood vessels, which can cause the development of ischemia femoral head necrosis and development. Increased incidence of avascular necrosis is seen in persons whose professional activity is connected with the high pressure (divers, miners). Improper blood decompression mode, fine air bubbles are formed, which can clog and damage the blood vessels, including the lead to disruption of blood flow in the arteries of the femoral head.
The symptoms of avascular necrosis
The first symptom is avascular necrosispain in the hip joint that occurs during the transfer of body weight to the "sick" leg. The pain may spread to the groin, buttocks, radiate (give) in front of the thigh. With the progression of the disease appears limp and impaired function (mobility) of the joint. In the later stages the pain can be saved and in peace, to promote sleep disturbance.
Diagnosis - aseptic necrosis
Diagnosis begins with avascular necrosisexamining a patient complaints, medical history and physical examination. The doctor will ask you about the presence of chronic diseases, taking drugs of occupational hazards. It may be asked about alcohol abuse. Physical examination includes inspection, palpation and joint study of its functions (angle abduction, flexion limbs, etc.). For clarification and confirmation of the diagnosis is necessary to conduct additional laboratory and instrumental methods of examination.
The X-ray area avascular necrosisfemoral head is determined, as a rule, at a sufficient duration of the disease. In the early stages of the disease X-ray examination of pathological changes in the bone can not be determined, in spite of the fact that the patient may have trouble severe pain in the joint. In the later stages of avascular necrosis joins osteoarthritis, and it is difficult to determine which of these causes of disease were observed in the patient's symptoms to a greater extent.
Radioisotope scan (scintigraphy)
In the absence of lesions onX-ray the doctor may prescribe radioisotope scan to confirm the diagnosis. In this method a drug containing a radioactive element (radiopharmaceutical) administered to the patient. After a few hours using a special gamma camera carried registration radioactivity in humans. In the absence of blood flow in the femoral head, this zone on a scintigram (image obtained by scintigraphy) are presented in the form of "cold" spots, since it is no accumulation of the radiopharmaceutical. After appearing in clinical magnetic resonance frequency of the destination of the radioisotope scan for the diagnosis of avascular necrosis has decreased significantly.
Magnetic resonance imaging
Currently, magnetic resonance imagingIt is the most frequently used research method for the diagnosis of the Academy of Sciences of the femoral head. The principle of magnetic resonance imaging is the imaging of tissues and organs of the body in the form of a series of sections with the help of electro-magnetic waves. It is the most informative and completely safe method of investigation. In MRI tomograms can be detected even minor areas with lack of blood flow and in the early stages of the disease.