This is done only when the disease is limited ...

Osteonecrosis (ON) is a focal infarction of bone that may be caused by specific etiological factors and may be idiopathic. This can lead to pain, limitation of movement, joint collapse, and osteoarthritis. Diagnosis by X-rays and MRI. In the early stages, surgical procedures may slow or prevent progression. In advanced stages, the joints may be required for pain relief and support functions. In the U.S., affects about 20 000 new patients a year. Hip (femoral head) most often affects, and knee and shoulder (humeral head). Wrists and ankles, rarely involved. It is unusual for ON involve the shoulder or the other, least of all affected areas without the hip are also involved. The most common cause of injury is ON. Nontraumatic ON affects men more than women, there are duplex

60% of cases and occurs mainly in patients aged 30 to 50 years. The most common cause of traumatic software is displaced subkapitalnyh hip fracture (see), with rare after mezhvertelnoy fractures. Frequency of ON after hip dislocation without notice high relief, early reduction occurs, the lower morbidity. Fracture or dislocation can lead to software compression or flagrant violation of the nearby blood vessels. Spontaneous knee (SPONK) localized on femoral condyles or tibial plateau in older women (sometimes men). SPONK believed that the destruction caused by the failure (such as fragility fracture caused by normal wear osteoporotic bone, which occurs without direct injury). Factors that cause or contribute to nontraumatic ON are listed in Table 1. The most common factors are:

25 mg / day for several weeks or months, resulting in a total dose usually

3000 mg. The risk also increases software when

500 ml ethanol / week), consumed for several years. Some genetic factors increase susceptibility to the software. Thin blood-clotting disorder due to deficiency of protein C, protein S, or antithrombin III or antykardiolipinovi antibodies (see

) can be detected in a high percentage of patients with ON. Some diseases that are allied with the software are treated with corticosteroids (eg, SLE), so it is not clear whether the increased risk through the use of corticosteroids or disorder. About 20% of cases of idiopathic. On the jaw has recently been lasix 40 mg reported in several patients who received high doses of bisphosphonates IV therapy (see Insert 1:

). About nontraumatic hip is bilateral in 60% of patients. Software includes the death of osteocytes and bone marrow. Mechanisms of nontraumatic software may include embolization of clots or lipid droplets, intravascular thrombosis, and extra vascular compression. After vascular image restoration processes are trying to remove necrotic bone and bone marrow and replace them with viable tissue. If a heart attack a little, especially if it is not subject to strong influence of gravity, this process can be successful. However, approximately 80% of cases, this process is not successful and myocardial gradually destroyed. Surface overlying the joints becomes flat and irregular, causing pain and increase eventually leads to osteoarthritis. Affected areas may remain asymptomatic for weeks or months after the vascular insult. Usually the pain, it develops gradually, although it may be acute. With the progressive collapse of the joint, pain increases and increases with motion and weight bearing and relieved by others. On the hip joint causing pain groin that may radiate into the buttocks or thigh. The movement is limited, and usually develops sluggishly. SPONK usually causes sudden pain without the prior knee injury. This pain is usually on the inside of the hip or knee joint plateau of the tibia and showing tenderness, joint effusion, painful movement and lameness. One of the humeral head often causes less pain and disability than the hip and knee involvement. In later stages of the disease, patients experience pain and reduced movement, while passive range of motion less affected than the active range of motion. Plain X-ray should be done first. They may show no abnormalities for months. The earliest records of localized outbreaks of sclerosis and lucency. Later, subchondral crescent sign may seem. Then gross collapse and flattening of the articular surface is visible, and advanced degenerative changes. When X-rays are normal or nediahnosticheskih, MRI, which is much more sensitive and more specifically, should be done. Both hips should be displayed. Bone scans are less sensitive and less specific than MRI. CT should rarely, but sometimes can be useful to identify joint collapse, which does not appear on plain X-rays. Laboratory studies are usually normal and great value in detecting ON. However, they can help identify the underlying disease (eg, breach of coagulation, hemoglobinopathies, lipid). Small, asymptomatic lesions may heal on their own and do not require treatment. Major injury as symptomatic and asymptomatic, with poor prognosis if untreated, especially when the head of the femur. Thus, early treatment to slow or prevent progression of joint and maintain desirable. Not completely effective treatment is yet. Non-surgical treatment includes drugs (eg bisphosphonates) and physical conditions (eg, electromagnetic fields and acoustic waves). Drug therapy and physical conditions have shown promise in limited studies, but are not currently public. Surgical treatment is most effective when you share collapse. They were used most frequently in treatment at the hip joint when the prognosis without treatment is worse than in other regions. Basic decompression procedure most often done, one or more nuclei of bone removed from the necrotic area or several small tracks or perforation made in an attempt to reduce intraosseous pressure and stimulate repair. Basic decompression is technically simple and complications is very low if the procedure is performed correctly. Protected weight bearing is necessary for 6 weeks. Most reports indicate satisfactory or good results in 65% of patients, including those whose hips have some degree of collapse, and in 80% of patients who have small hips, early lesions. Other established treatments include a variety of osteotomy of the proximal femur and bone grafts as vascular nonvascularized. These procedures are technically challenging, requiring protection of bearings weighing up to 6 months and has been done only in the U.S.. Reports are that their indications and efficacy. They should be made primarily on individual centers with surgical expertise and capabilities to achieve optimal results. The approach being evaluated is the introduction of autologous bone marrow necrotic lesions. If a big collapse of the femoral head and degenerative changes in vertluzhnoy cause sufficient pain and disability of the joints usually the only way to effectively relieve pain and increase the amplitude of movement. The traditional approach total hip arthroplasty. Good to excellent results achieved in 95% of the total hip and total knee replacement, the incidence of complications is low, and most patients resume daily activities within 3 months. Most prosthetic hip and knee last >> << from 15 to 20 years. Two options studied include surface replacement arthroplasty (SRA) and semi-SRA. SRA, which can be done, rather than total hip arthroplasty, include a 2 metal lid, one in vertluzhnoy basin and one in the femoral head, producing a metal-metal articulation. Hemi-bid involves placing a metal cap at only the femoral head. This is done only when the disease is limited to the femoral head and the waiting is the procedure. On lap and shoulder can be managed conservatively more often than the hip. Limited experience with basic decompression was promising. In advanced stages, partial or total joint arthroplasty may be indicated. Risk in due corticosteroids can be reduced to a minimum, using them only when the principal and giving them a low dose as necessary and in so short a time as possible. For the prevention of decompression sickness caused people should follow accepted guidelines for decompression when submerged and when working in tight conditions. Excessive drinking and smoking should be discouraged. Various medications (eg, anticoagulants, vasodilators, lipid lowering drugs) are currently estimated to prevent software in high-risk patients. Last full review / revision March 2008 Marvin E. Steinberg, MD.