Sonographic finding of a pulled elbow: the "hook sign"

Point-of-care ultrasound has become a useful clinical adjunct, especially in emergency medicine, because it is noninvasive, repeatable, and nonradiating. In cases of pulled elbow also known as nursemaid's elbow or radial head subluxation, diagnosis is usually performed clinically. However, there is the potential for a failed reduction or misdiagnosis. We introduce a potentially useful diagnostic finding for pulled elbow ("Hook sign") using point-of-care ultrasound in the emergency department.