Compound is an old term.
Open fracture is how it is described now.
Means the bone broke and tore the skin from inside-out.
Go to video at https://t.co/ameoYFCQs5 to see why fortunately this will not be an "Alex Smith" situation. WARNING: Graphic video.

— David J. Chao - ProFootballDoc (@ProFootballDoc) October 12, 2020