0:00

This 25-year-old has pain when swinging the arm.

0:05

There's actually no history of discrete

0:07

collision or catastrophic trauma, and that's

0:10

usually the case, uh, for this type of lesion.

0:14

So the patient's young, 25 years of age,

0:17

and we've got a labeled image on your left.

0:21

On the right side, we've got a gradient echo,

0:24

a simple standard water-weighted gradient echo.

0:27

And, um, let's scroll it a little bit.

0:32

And let's you get a feel for, um, the labrum.

0:37

And you can see we've labeled the

0:39

labrum at the area of interest.

0:42

And again, the, the labrum is abnormal at one slice down.

0:46

So we'll go to the exact same slice and then one slice down.

0:49

Back, down.

0:51

And then things look a bit normal again.

0:53

In fact, they are normal.

0:55

Nice black labral ligamentous complex.

0:58

This is a 1 Tesla.

0:59

High field open.

1:01

So we're looking at a partial rim

1:03

tear that involves the labrum.

1:06

Now I'm going to take my drawing tool out and I'm going to

1:10

draw over this image here and use it as my reference point.

1:15

I'll make my scapula nice and orange and then I'll

1:19

take a nice color and make my labrum here and then

1:23

I'll make my labrum over here and then I'll make

1:28

my hyaline cartilage aquamarine blue just for fun.

1:33

for consistency.

1:35

And, um, let's talk about this particular

1:38

lesion, which is known as a glenolabral articular

1:42

disruption, a type of rim injury that is incomplete.

1:46

So if I, if I blew up my labrum, I'd say,

1:49

well, what's happening in the labrum?

1:51

I'm having a partial tear in the labrum.

1:55

It's coming from the inside out.

1:57

And frequently, it'll clip the tissue.

1:59

The base of the aquamarine blue hyaline

2:02

cartilage, which is going to be over here.

2:04

So you get a little bit of cartilaginous

2:06

involvement, and then your tear, which

2:08

is in green, goes right into the labrum.

2:14

How is that any different than a, a true Bankart lesion?

2:18

And a true Bankart lesion is, is

2:20

actually an avulsion type of labral tear.

2:23

That's how it was originally described.

2:26

And if we took our green arrow, sorry, our green

2:29

label, and we made a true Bankart, it would go all

2:32

the way through, out the other side of the labrum.

2:36

Now, what, what happens here, what

2:39

happens over here to the labrum?

2:42

It merges imperceptibly with

2:44

capsular tissue, and with periosteum.

2:48

And often you can't separate them apart.

2:50

So let's make our periosteum, Uh,

2:53

let's try deep blue in honor of IBM.

2:57

There's deep blue right there.

2:59

And, so your true Bankart lesion, which again we'll

3:05

make in, in green, uh, I'll make it a lighter green

3:08

this time, and it, it can go through the periosteum.

3:12

So it doesn't have to go through the labrum.

3:14

So avulsion through this area or this

3:17

area is consistent with a true Bankart.

3:22

Now the next question you're probably gonna ask

3:24

me is what's the definition of a Perthes lesion.

3:31

Let's, let's do that.

3:32

I'm gonna have to take my eraser out.

3:34

I think that's it right there.

3:37

Nice erasing.

3:39

Love this little system here.

3:41

Of course, I'm an artist at heart.

3:44

A failed artist, but, uh, so I love to draw.

3:48

And, um, let's make our labrum again.

3:53

And here's our, here's our labrum.

3:55

This time I'm going to have to put some glenoid

3:57

tissue in there, so let's put our glenoid tissue in.

4:02

And then we've also got some aquamarine hyaline cartilage

4:05

in there, and sometimes it'll be a fuzzy transition

4:08

into the labrum, sometimes it'll be quite abrupt.

4:12

And our labrum is going to transition

4:14

into the capsule and the periosteum.

4:17

So in a Perthes lesion, you do not

4:20

have a through and through tear.

4:23

You have a tear that goes into the labrum,

4:25

But then dissects underneath the periosteum.

4:29

But there's still a periosteal unit that stays intact.

4:34

So if we said, okay, what does the tear actually look like?

4:38

I'm going to take a tear color that's consistent.

4:41

Let's go with, um, let's go with dark green again.

4:45

So I'm going to take my dark green.

4:48

My tear goes into the labrum and then it makes a,

4:51

a turn medially and goes underneath the periosteum.

4:55

It'll lift the periosteum up.

4:57

And sometimes even the periosteum will puff up like this.

5:02

It'll get lifted all the way up, but still attached.

5:05

And filling it in will be this inflammatory

5:08

material, and injurious material, that

5:11

gives you a little pseudomass right there.

5:13

So, the Perthes lesion differs significantly from

5:18

the true Bankart, in that it is not an avulsion.

5:21

It can occur from a dislocation or a minor trauma.

5:25

Usually GLAD lesions, glenolabral articular

5:28

disruption, like this lesion, where the periosteum

5:31

is intact, and there's a partial rim tear starting

5:35

at the base of the cartilage going into the labrum.

5:38

These are most often seen in lower grade

5:42

types of injuries, lower velocity injuries.

5:45

And the patients usually have odd complaints, you know.

5:48

Pain when swinging the arm, pain when internally rotating.

5:52

When they rotate the arm, they feel like the shoulder

5:54

is giving way, but when you examine it, they don't lock.

5:57

They don't dislocate on physical examination,

6:00

but they do have some degree of loosening.

6:03

And sometimes, even on MRI, if you internally and

6:06

externally rotate the shoulder by putting the arm behind

6:10

the back, with the thumb up and the thumb down, As the

6:14

humerus rotates this way, like this, in and out, the

6:19

labrum will swing in and out, and it'll get caught, and

6:22

the patient may experience a tiny little click, or a

6:25

sensation of a click, or you may even hear an audible sound.81 00:04:12,095 --> 00:04:14,825 And our labrum is going to transition

4:14

into the capsule and the periosteum.

4:17

So in a Perthes lesion, you do not

4:20

have a through and through tear.

4:23

You have a tear that goes into the labrum,

4:25

But then dissects underneath the periosteum.

4:29

But there's still a periosteal unit that stays intact.

4:34

So if we said, okay, what does the tear actually look like?

4:38

I'm going to take a tear color that's consistent.

4:41

Let's go with, um, let's go with dark green again.

4:45

So I'm going to take my dark green.

4:48

My tear goes into the labrum and then it makes a,

4:51

a turn medially and goes underneath the periosteum.

4:55

It'll lift the periosteum up.

4:57

And sometimes even the periosteum will puff up like this.

5:02

It'll get lifted all the way up, but still attached.

5:05

And filling it in will be this inflammatory

5:08

material, and injurious material, that

5:11

gives you a little pseudomass right there.

5:13

So, the Perthes lesion differs significantly from

5:18

the true Bankart, in that it is not an avulsion.

5:21

It can occur from a dislocation or a minor trauma.

5:25

Usually GLAD lesions, glenolabral articular

5:28

disruption, like this lesion, where the periosteum

5:31

is intact, and there's a partial rim tear starting

5:35

at the base of the cartilage going into the labrum.

5:38

These are most often seen in lower grade

5:42

types of injuries, lower velocity injuries.

5:45

And the patients usually have odd complaints, you know.

5:48

Pain when swinging the arm, pain when internally rotating.

5:52

When they rotate the arm, they feel like the shoulder

5:54

is giving way, but when you examine it, they don't lock.

5:57

They don't dislocate on physical examination,

6:00

but they do have some degree of loosening.

6:03

And sometimes, even on MRI, if you internally and

6:06

externally rotate the shoulder by putting the arm behind

6:10

the back, with the thumb up and the thumb down, As the

6:14

humerus rotates this way, like this, in and out, the

6:19

labrum will swing in and out, and it'll get caught, and

6:22

the patient may experience a tiny little click, or a

6:25

sensation of a click, or you may even hear an audible sound.

6:30

So this is known as functional instability.

6:33

It's a type of micro instability.

6:35

It's anterior quadrant, and one of the causes

6:40

of this type of instability is the GLAD lesion.

6:44

So in summary, you've gotten a definition of a true Bankart

6:47

lesion, the periosteal type, or the soft Bankart type.

6:51

You can also have a bony Bankart, which

6:53

we're not going to discuss right now.

6:55

We talked about the Perthes lesion, originally

6:58

described, by the way, in 1906, a long, long time ago.

7:02

So this isn't something new.

7:04

That we created in the Perthes lesion.

7:07

The periosteum remains intact.

7:10

And there's a partial tear of the labrum

7:12

with the section underneath the periosteum.

7:15

And then we talked about the GLAD lesion.

7:18

In which the periosteum isn't elevated.

7:21

There's just a partial rim tear into the labrum.

7:24

It doesn't go through.

7:25

It doesn't elevate the periosteum.

7:27

And just as a caveat.

7:29

Uh, any variations of these can occur posteriorly.

7:32

But the one that's most famous.

7:35

is the reverse Perthes lesion, also

7:37

known as the Kim's variant lesion.

7:40

And that'll be a story for our

7:42

posterior instability discussion.

7:45

Let's move on, shall we?