Rapid screening for the posterior fat pad sign in suspected pediatric elbow fractures using point-of-care ultrasound: A "FAST exam" for the traumatized elbow

Abstract

Purpose Children with elbow injuries frequently present to the emergency department for evaluation. Fractures of the elbow are sometimes not visualized on plain radiographs and the only sign of an occult fracture is an elevated posterior fat pad that normally sits within the olecranon fossa. The elevated posterior fat pad sign is highly sensitive and its absence likely rules out fractures of the elbow and can be readily visualized by ultrasound. Lipohemarthrosis within an elevated fat pad can also be visualized by ultrasound, but not by X-ray. This finding with an elevated posterior fat pat adds additional specificity to rule in elbow fractures. Methods We report the use of point-of-care ultrasound to rapidly screen for the presence of the posterior fat pad sign and lipohemarthrosis in a series of children presenting with elbow injuries to the emergency department. Results Point-of-care ultrasound identified elevated and normal posterior fat pads that correlated with X-ray. Lipohemarthrosis within an elevated fat pad was also detectable by ultrasonography. Conclusions Knowledge of whether a posterior fat pad is elevated or not and noting the presence of lipohemarthrosis by using point-of-care ultrasound may be helpful to expedite diagnosis and treatment of these patients, especially in settings with no access to plain radiography. © Springer-Verlag 2010.