A 30-year-old man comes to the emergency department due to left eye pain after being involved in a street fight. He received a fist blow to the left eye and has since had pain and diplopia. Past medical history is notable for 2 previous gunshot wounds. The patient does not smoke cigarettes but has a history of heavy alcohol intake and frequent marijuana use. On examination, there is significant soft tissue swelling around the left eye. Visual acuity is normal, but extraocular motility of the left eye is limited. Pupillary reflexes are normal. Coronal CT scan of the orbits is shown in the image below. The orbital contents of this patient are most likely to herniate into which of the following sites?

Question

A 30-year-old man comes to the emergency department due to left eye pain after being involved in a street fight.  He received a fist blow to the left eye and has since had pain and diplopia.  Past medical history is notable for 2 previous gunshot wounds.  The patient does not smoke cigarettes but has a history of heavy alcohol intake and frequent marijuana use.  On examination, there is significant soft tissue swelling around the left eye.  Visual acuity is normal, but extraocular motility of the left eye is limited.  Pupillary reflexes are normal.  Coronal CT scan of the orbits is shown in the image below.  The orbital contents of this patient are most likely to herniate into which of the following sites?

Quizplus · Accepted Answer

The orbit is bound superiorly by the thick orbital plate of the frontal bone and laterally by the thick bone of the zygoma and greater and lesser sphenoid wings. In contrast, the orbital floor is composed of a very thin layer of bone that separates the orbit from the air-filled maxillary sinus. Similarly, the orbit's medial wall is composed of the thin ethmoid and lacrimal bones, which separate it from the ethmoid air cells. Blunt trauma to the eye causes a rapid increase in pressure that typically does not rupture the globe but is transmitted posteriorly into the orbit. The weakest plates of bone in the orbit, the medial and inferior walls, are common sites of fracture. Fracture is typically evident on radiographic imaging, and fluid (eg, blood) or herniation of the orbital contents can often be visualized in the adjacent normally air-filled sinuses. (Choice A) The ethmoid air cells are medial to the orbit. They are unaffected in this patient, but they can be affected in blowout fractures of the orbit's medial wall. (Choice B) The frontal sinus is not pictured above. It lies in the medial part of the supraorbital frontal bone. (Choice C) The inferior nasal conchae form part of the nasal turbinate system. They are not air-filled sinuses. (Choice E) The sphenoid sinuses (not pictured above) lie anterior to the optic chiasm and are not in close relation to the orbit. Educational objective: Blunt trauma to the globe can cause orbital blowout fractures. These fractures most commonly involve the medial or inferior orbital walls due to the thin bone bordering the ethmoid and maxillary sinuses.

A 30-Year-Old Man Comes to the Emergency Department Due to Left