0:01

This was a patient who presented several days

0:04

after a traumatic event with a blow to the

0:10

occipital region and temporal

0:12

region on the right side.

0:14

The patient had conductive hearing loss in the

0:18

clinic and was sent for temporal bone CT.

0:23

This is a relatively subtle case in which

0:28

because it was not an acute fracture,

0:31

and what you see is an irregularity

0:36

along the temporal bone,

0:39

which is coursing right along this plane right here.

0:44

Here you can see the little small fracture line

0:48

along the mastoid portion of the temporal bone

0:51

that was indicative of the fracture.

0:54

And there may have been a little bit of

0:58

irregularity along the anterior margin

1:00

of the external auditory canal.

1:02

Sometimes you will see these little lines of the...

1:05

these lines along the

1:09

anterior margin of the external auditory canal.

1:11

They don't necessarily represent fractures.

1:14

It could just be some fissures.

1:15

But the important finding here was not so much

1:18

the fracture as it was a,

1:20

look at the middle ear ossicles.

1:23

So when we look at the middle ear ossicles,

1:25

what we see is a gap between the long process of

1:31

the incus and the capitulum of the stapes.

1:35

Let me really mag that up.

1:37

What I'm talking about is, here we have our head

1:40

of the malleus, short process of the incus,

1:42

the long process of the incus.

1:44

And normally you have a good-looking

1:46

incudostapedial joint,

1:49

particularly when you're using thin-section

1:51

images. These are 0.4 millimeter thick.

1:54

Let's look at the contralateral side for those

1:56

people who are wondering whether

2:00

I'm just making it up.

2:02

So, let me move over to the other side.

2:08

And here we have our incus coming down.

2:12

And look, the nice incudostapedial

2:14

joint right there.

2:16

Here's the capitulum near the crura of the

2:18

stapes. And that's a nice-looking joint.

2:21

Contrast that with this, where we have this gap.

2:25

So this is an example of incudostapedial

2:28

dislocation secondary to a fracture with a

2:32

patient who presented after a delay with

2:35

conductive hearing loss because, obviously,

2:37

the incus was no longer attached to the stapes.

2:41

The fracture site itself was obscured because it

2:44

was a delayed presentation with just a little

2:48

bit of a line here through the mastoid bone.

2:51

And again, the longitudinal or otic capsule

2:54

sparing fractures,

2:55

or the ones that are more commonly associated

2:57

with ossicular dislocations.