Flattening of the normally spherical femoral head indicates collapse. On radiographs, a subchondral lucent line may be seen, representing a fracture. When a patient with established AVN presents with acute pain, the suspicion and imaging should be directed toward finding articular collapse, which is often very subtle. Patients may go on for many years at the prior stage. At this point, patients may be asymptomatic. Typically, the surrounding marrow edema has resolved. The margins demonstrate the classic “double line sign” of Mitchell, representing the interface between living and dead bone with a rim of granulation tissue. The central signal is variable, often high on T1 (trapped/mummified fat) but occasionally bright on T2 or dark on all sequences (fibrotic). In stage 2 in which increased radiographic density is seen, MRI demonstrates a focal subchondral geographic signal abnormality, usually centered anterosuperiorly. In later stages, it is easier to document the finding as AVN. Waltham, MA: UpToDate Inc.Table 11-1 Modified Ficat Staging System for Avascular Necrosis of the Hip Radiologic evaluation of the acutely painful knee in adults. Clinical decision rule for knee radiographs. Prospective validation of a decision rule for the use of radiography in acute knee injuries. Stiell IG, Greenberg GH, Wells GA, et al. Derivation of a decision rule for the use of radiography in acute knee injuries. Diagnostic accuracy and reproducibility of the Ottawa Knee Rule vs the Pittsburgh Decision Rule. J Am Coll Radiol 2015 12:1164.Ĭheung TC, Tank Y, Breederveld RS, Tuinebreijer WE, de Lange-de Klerk ES, Derksen RJ. ACR Appropriateness Criteria Acute Trauma to the Knee. Tuite MJ, Kransdorf MJ, Beaman FD, et al. National Hospital Ambulatory Medical Care Survey: 2007 emergency department summary. Radiographic detection of hip and pelvic fractures in the emergency department. Prevalence of traumatic hip and pelvic fractures in patients with suspected hip fracture and negative initial standard radiographs-a study of emergency department patients. ĭominguez S, Liu P, Roberts C, Mandell M, Richman PB. Imaging Evaluation of the Painful Hip in Adults. ACR Appropriateness Criteria® Acute Hip Pain-Suspected Fracture. Declining hip fracture rates in the United States. Therapies for treatment of osteoporosis in US women: cost-effectiveness and budget impact considerations. Tosteson AN, Burge RT, Marshall DA, Lindsay R. Less than 12 or greater than 50 years old.Īnyone who cannot take 4 weight-bearing steps in the emergency department The sensitivity is not quite as high as the Ottawa Knee Rule, however, its simplicity may be preferable. Anyone who meets the following criteria should be evaluated with a knee x-ray. The sensitivity of this decision rule has been reported at 92%. Pittsburgh Decision tool: for acute knee trauma. Several studies have found a 100% sensitivity for acute fracture using this rule (…that’s pretty good).Ĭannot walk in the emergency department (after taking 4 steps) If any of the following criteria are met, knee x-ray should be obtained. Ottawa Knee Rule: for patients older than 18 years of age with acute knee pain. While using these rules may assist ED physicians to decide when to forgo a plain film, the radiologic evaluation of acute knee pain should always begin with an x-ray. There are two clinical decision tools for acute knee pain. Acute knee pain is most often caused by trauma, followed by infection and crystal-associated inflammation. Unlike hip pain, knee pain is more common in the pediatric and adolescent populations. In fact, one study found that over 500,000 visits per year were attributed to knee pain. Acute knee pain accounts for a large number of emergency department visits.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |