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Okay, this is a 17-year-old wrestler.

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He's had some shoulder discomfort and he experienced

0:08

an acute event while he was on the mat.

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Although he didn't report an overt

0:13

dislocation and did not have to be relocated.

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Let's begin with our axial gradient echo image.

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And he's got a little bit of infolding in

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the capsule, and that is reflected by this

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volume-averaged area of capsular tissue.

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It's getting trapped inside and producing

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a little bit of swelling and edema.

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That is actually not where his

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physical examination is positive.

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He lifts a lot of weights.

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You can see how muscular he is.

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Let's go to the coronal projection for a moment.

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The proton density fat suppression.

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Now one of our cardinal rules is when you go

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from anterior to posterior, you should not see

0:55

a cleft or signal appear in the superior labrum.

0:58

And we are going from anterior, that's a recess, to

1:02

posterior, and we suddenly see within the labrum,

1:05

within the triangle, focal signal intensity.

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So he's got a SLAP lesion.

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So is it a SLAP II, just superior,

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or does it slide down the back?

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And it is sliding down the back,

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which is known as a SLAP VIII.

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One of the more common SLAP lesions, extremely

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common in young athletic boys who do a lot of

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weightlifting and physical pushing activity.

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So now let's turn our attention

1:37

back again to the axial projection.

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We'll start up high, where the SLAP lesion began.

1:43

Right there.

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You can see it as a whitish area.

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In fact, I'll color it in with my pen

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so you can see it a little better.

1:49

Right there.

1:50

Looks a little different than the

1:52

rest of the hyaline cartilage.

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Now, let's track it down.

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There it is again.

1:58

And this is all chronic.

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Let's keep going.

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Still present.

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There's a little bit of swelling in the periosteum.

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Let's keep going.

2:07

It's more slit-like now.

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Let's keep going.

2:10

Now it's more pouch-like.

2:12

Now it's very pouch-like.

2:15

So, the labrum is separated from the glenoid

2:19

by just a little bit, with a little pouch, with an

2:23

attachment to a lip of the periosteum, and you

2:26

might refer to this as a reverse Perthes lesion.

2:30

There are some that might call this a Kim's lesion.

2:34

I tend to call a Kim's lesion when

2:36

I don't have wrap around the back.

2:38

When I simply have separation here, rather than here.

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That's just how I do it.

2:44

So for me, a Kim's lesion is like

2:46

a baby reverse Perthes lesion.

2:50

So let's keep going, shall we?

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Let's keep going down.

2:53

There's our little pouch of separation,

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still with periosteal attachment, and still,

2:58

and still, and still, and then maybe not.

3:05

Definitely not.

3:06

There's a little space right here.

3:08

There's some stripped periosteum.

3:10

There's some stripped periosteum.

3:12

I think this image shows it the best.

3:14

So, now we're dealing with a posterior caudal injury, where

3:19

we have strengthened or worsened this peel-back effect.

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So, now the periosteum has come off a

3:27

little bit with, with the labrum itself.

3:32

And now we're starting to transition

3:34

into more of a polpsa lesion.

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A posterior labroperiosteal sleeve avulsion.

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To be differentiated, of course, from a palypso lesion,

3:44

where the labrum would be on and the capsule would be off.

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Posterior labrum intact, periosteal sleeve avulsion.

3:51

So you can see this young man sustained a minor injury on

3:57

top of another minor injury in the superoposterior labrum.

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So he started out with a superoposterior SLAP VIII,

4:07

he had a reverse Perthes lesion, and he progressed

4:11

that more caudally to a small polpsa lesion.