Children With Elbow Injuries and Sonographic Elevated Posterior Fat Pad but No Identifiable Posterior Fat Pad on Lateral Radiographs: A Case Series

Point of Care Ultrasound (POCUS) is used to evaluate the injured pediatric elbow. Standard of care, however, remains radiography. POCUS performed in the setting of normal radiographs have been obtained may demonstrate radiologic occult lipohemarthrosis indicative of occult fracture. We reviewed our pediatric emergency department (PED) POCUS archive for lipohemarthrosis, and then isolated those cases with normal elbow radiography. Radiography was deemed to be normal per the interpretation of the treating PED physician, and was reviewed for this series by an experienced ABR board certified pediatric radiologist. Fracture on POCUS was defined as fracture line or lipohemarthrosis in a posterior sagittal or transverse view of the distal humerus. Fracture was confirmed by signs of cortical healing on follow-up radiography, or clinical course consistent with fracture as documented by an orthopedist. We identified four children with elbow fractures who had no fracture line or elevated posterior fat pad on radiography but demonstrated lipohemarthrosis on POCUS. POCUS may elicit evidence of fracture even after normal radiography, and POCUS findings suggesting occult fracture may allow for more effective guidance on discharge.