Point-of-Care Ultrasound: Sonographic Posterior Fat Pad Sign: A Case Report and Brief Literature Review.

BACKGROUND: Diagnosis of elbow fracture can sometimes be difficult with plain radiography due to overlapping bones, growth plates, and maturing bones in the pediatric population. The radiographic posterior fat pad (PFP) sign is one of the frequently referenced indirect signs of an occult elbow fracture. This sign can be falsely negative if the sign is subtle, and can be falsely positive when the position of the elbow is not flexed at 90 degrees.

CASE REPORT: We discuss a case in which sonographic PFP sign helped to diagnose an elbow fracture. A 57-year-old female presented to the emergency department (ED) after a fall on an outstretched hand. The point-of-care ultrasound (POCUS) was completed identifying an elevated PFP and an anechoic joint fluid collection with innumerous floating hyperechogenic spicules visualized in the olecranon fossa. Diagnosis of a radial head fracture was later confirmed by plain radiograph. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The increase in use and availability of POCUS in the ED makes this a very practical application. Our ability to rapidly perform the ultrasound of the elbow may allow us a more rapid diagnosis of pathology, as well as provide a way to further triage our patients. With time, it may even allow us to avoid routine use of plain radiography.