Bone infarction - Diagnosis

Imaging Studies:Plain radiography in diagnosing osteonecrosis is established. In the epiphyseal region is observed in the form of an arch injury, subchondral, associated with areas of opacity radiolucenta bone and bone areas of sclerosis or collapse. In a radiolucenta diametafizeala region is surrounded by a peculiar calcification and sclerosis or periostitis. In flat bones or complex radiolucenta stained and are often associated with sclerosis and collapse of bone fractures.In post-traumatic osteonecrosis of the infarcted bone is opaque, the femoral head is the most common location. Radiography in a few months after symptom onset shows crescent radiolucente parallel with subchondral collapse of the articular surface secondary necrotic bone.
MRI is useful in identifying changes in bone marrow. These changes occur 6-12 hours after stroke. Ischemia is detectable in osteophytes, osteoblasts and osteoclasts in two days. Describe the inflammatory response around the bone devascularizat with vascularitatii growth and granulation tissue. Features infarcted bone are low intensity spots. The most characteristic element is the appearance of a double linear hyperintense ring hipointens internal and one external. MRI is considered more sensitive than bone scintigraphy.
Echography and scintigraphy are used in combination to differentiate osteomyelitis from bone infarction in patients with sickle cell disease. It is useful in confirming and guiding aspiration fluid subperiostial to distinguish a hematoma from an abscess.bone scintigraphy to identify focal increased activity in spontaneous osteonecrosis of the knee before radiographic changes.Angiography: intramedullary phlebography is used in the diagnosis of bone infarct of the femoral head. This technique involves passing a needle trohanterian bone and injecting dye. Normal injection is painless and shows the venous drainage shaft without reflux or stasis. When is this injection of femoral head necrosis is painful and is followed by reflux in the shaft and stasis in 15 minutes.
The differential diagnosis is made with the following conditions: storage disease calcium phosphate, Legg-Calve-Perthes disease, Charcot joint, osteochondritis dissecans, fracture stress, inflammation, neoplastic processes, osteoporosis, osteoarthritis secondary.