PMC:3945237 / 15851-16657 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/3945237","sourcedb":"PMC","sourceid":"3945237","source_url":"https://www.ncbi.nlm.nih.gov/pmc/3945237","text":"CT scans do not demonstrate the early vascular and marrow abnormalities that result in osteonecrosis [21].Osteoporosis is the first visible sign. Later, the central bony asterisk is distorted, appearing as clumping and fusion of the peripheral asterisk rays. Clumping appears as spots or as hyperdense \"roads\" of various width (figure 9). This represents changes in the sclerotic interface between necrotic and viable bone and is analogous to the line of low signal surrounding the necrotic bone seen on MRI images. Early signs are caused by microfractures resulting from reduced mechanical load of dead bone trabeculae, altering the shape of the asterisk. Signs also are related to new bone formation on the dead trabeculae. The lucent cystic region, representing the reparative zone, may be appreciated.\n","tracks":[]}