Orbital blowout fracture
Orbital blowout fracture. This injury occurs as a result of a direct blow to the orbit, resulting in a fracture of one or more of the orbital walls. Potential mechanisms include, in Dublin 4, a squash or hockey-ball injury or, in other locations, a punch or a blow with a sliotar. As a result of the fracture, some of the contents of the orbit may be displaced into one of the paranasal sinuses. In this example, there is a fracture of the inferior floor of the right orbit, and there is evidence of orbital contents (such as the inferior rectus muscle) bulging into the right maxillary sinus (yellow arrow). There is an air-fluid level in the sinus in this example (orange arrow), which is due to haemorrhage and is a very helpful radiographic sign when the fracture itself is less obvious. CT is usually performed in these cases; in this example, it confirms the displacement of some orbital fat through the fracture (arrow).