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Case 2 - Orbital Apex and Roof Fracture

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This was a young child who fell out of a stroller

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and landed and hit the facial structures.

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And this case will demonstrate some of the

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more unusual types of orbital fractures.

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So I'm just going to focus on the axial CT scans

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and point out a few findings.

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So obviously,

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first thing we will see is the air fluid level in the

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right maxillary antrum and the left maxillary antrum.

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We see that the patient has nasal bone fractures,

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which we'll discuss in a moment.

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But let's focus on the orbit.

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So as we come up further superiorly on the right side,

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focusing there,

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we see some air at the foramen rotundum.

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We see some air coursing to the superior orbital fissure,

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and we see some air cutting across the

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anterior clinoid process.

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This is a fracture which is crossing the orbital apex.

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Here is the optic nerve canal, the optic canal.

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And the fracture goes just above the optic canal

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with small areas of air seen in that location.

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You notice that it communicates across to the

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medial orbital wall at its posterior most portion.

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This is a very unusual location for

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a fracture at the orbital apex.

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But it points out what the risk factor is, that this

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can then, at this narrowest portion of the orbit,

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lead to a compression of the optic nerve

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when you have a hematoma there.

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Although we will talk a little bit

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more about this case later on

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when we're talking about the other types of fractures.

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I do want to point out that this patient also has

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a fracture which goes across the top of the

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orbit. So orbital roof fractures.

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These are usually when there is a big pressure in the

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orbital space that drives the fracture generally

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superiorly into the intracranial compartment.

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So we have to be very careful here about our coronal images.

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I want to point out that these are the thin section,

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0.75 millimeter thick sections. I've shown you

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previously coronal and sagittal reconstructions.

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You notice that the coronal and sagittal reconstructions

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are two millimeter or three millimeter

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in some of the examples I gave you.

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It is not uncommon for me to make my own coronal and

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sagittal reconstructions from the 0.75 mm.

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So that way I have even thinner section than what is

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provided to me by the technologists or

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the scanner that are two to 3 mm.

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So if you need that higher resolution,

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take those thin sections at 0.75 and

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reconstructive and coronal, and sagittal also in thin section.

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Here we can see a large laceration with a foreign body

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over the forehead. Let's look at the coronal reconstruction.

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So in this example, you can see the orbital roof fracture,

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which is shearing off a portion of the anterior clinoid

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process, and we are... here is the optic canal.

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So in point of fact,

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the fracture doesn't actually cross the optic canal.

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It's just in close proximity to it.

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But we do see the fracture involving the roof

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of the orbit. Note the small amount of air.

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I'll magnify that for you.

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So here's the small amount of air.

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Again, whenever I see that,

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I'm going to be very suspicious of an adjacent

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fracture. And here that fracture is.

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And the next thing we want to do is

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to look at the soft tissue windows.

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Why do we want to look at the soft tissue windows?

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We want to look of the orbital apex to see whether this optic

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nerve is being compressed at all by adjacent

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hemorrhage associated with the fracture.

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And this is about as good as you're going to see symmetry

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from side to side in the orbital apex.

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So, in point of fact,

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there isn't a large hematoma associated with this fracture

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that was involved in the interclinoid and the

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soft tissues just adjacent to the optic canal.

Report

Faculty

David M Yousem, MD, MBA

Professor of Radiology, Vice Chairman and Associate Dean

Johns Hopkins University

Tags

Neuroradiology

Head and Neck

Emergency

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