Radial head fractures are relatively common injuries, typically after indirect trauma to the elbow, for example a fall.

An effusion is often the sign that there is an undisplaced fracture, as fluid in the joint capsule elevates the fat pad.

This can be seen even without an obvious fracture so is an important area to review. This case was recalled for further imaging due to ongoing pain and shows a clear fracture at the radial head which was not appreciable on the original imaging.