Seen in the ED: Name this Elbow Injury

A 20-something young man is in the ED after a fall off a scooter while doing tricks. What do you see on the x-ray? What type of injury is it?

Patient history. A man in his 20s presents to the emergency department (ED) for elbow pain and deformity after a fall from a scooter while doing tricks. He denies any neck or back pain or other complaints and was wearing a helmet but no elbow pads or other protective gear.

Vital signs & physical examination. Vital signs are normal. Physical exam is otherwise normal except for tenderness and swelling to the elbow. His distal neurovascular exam is intact

Relevant test results. Imaging, below.

What is the most likely diagnosis?

Find more puzzling presentations in Patient Care's collection of Dr Pregerson's "Seen in the ED" cases.