Blowout fracture

A blowout fracture is a fracture of the walls or floor of the orbit. Intraorbital material may be pushed out into one of the paranasal sinuses. This is most commonly caused by blunt trauma of the head, generally personal altercations. The term "blow out fracture" was coined in 1957 by Smith & Regan, who were investigating injuries to the orbit by placing a hurling ball on cadaverous orbits and striking it with a mallet. The force of a blow to the orbit is dissipated by a fracture of the surrounding bone, usually the orbital floor and/or the medial orbital wall. Serious consequences of such injury include diplopia on downward gaze if there is damage to the floor of the orbit.