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0:41

Today, we're honored to welcome

0:43

Dr. Stephen Pomeranz

0:44

for a lecture on shoulder MRI.

0:46

Dr. Pomeranz is the founder of MRI Online,

0:49

authored numerous medical textbooks in MRI

0:52

including The MRI Total Body Atlas.

0:55

Avid conference lecture.

0:56

Chairs fellowship training programs in

0:58

MR and advanced imaging.

1:00

Chair of Naples Florida Community Hospital Network.

1:03

CEO and medical director of ProScan Imaging.

1:06

At the end of the lecture,

1:07

please join Dr. Pomeranz in a Q and A session.

1:10

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1:11

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1:13

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1:15

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With that being said,

1:45

we are ready to begin today's lecture.

1:47

Dr. Pomeranz, please take it from here.

1:50

All right, we're talking MRI of the shoulder today.

1:53

This is not an intermediate...

1:57

This is an intermediate lecture.

1:58

It is not an introductory lecture.

2:01

And the shoulder is the most difficult

2:03

joint in MRI, followed by the hip.

2:07

These are my disclosures.

2:09

I have nothing else to disclose

2:11

other than what's been said.

2:12

And I'd like to start out

2:13

with this video of the great

2:15

pitcher or throwing athlete, Sandy Koufax.

2:18

And I'm going to stop this video if it will let me.

2:21

A little further in.

2:23

Right there,

2:24

where Sandy Koufax has his arm in the

2:27

abduction external rotation position.

2:29

In fact, the ball is on the opposite side of his

2:32

other ear, even though he is throwing

2:34

with his left arm.

2:35

So look at how much abduction and

2:37

external rotation he's in.

2:39

This is known as the cocking phase

2:41

of the throwing motion.

2:43

And this is where the infraspinatus and posterior

2:45

superior labrum get crushed in the

2:47

phenomenon of internal impingement syndrome.

2:50

Then as he follows through,

2:53

the dynamic phase,

2:54

we didn't catch because it's so fast.

2:56

But the follow-through phase is where

2:59

the anterior labrum and infraspinatus may be

3:02

affected in certain impingement-type conditions.

3:06

And we will talk about those a little later on.

3:08

But understanding the biomechanics of

3:10

the shoulder is integral and essential

3:13

in becoming a world-class,

3:15

excellent shoulder MSK radiologist.

3:18

Today, we're going to cover the rotator cuff,

3:20

the labrum and at the very end,

3:22

if time allows,

3:23

we'll speak briefly about Bennett Lesion.

3:27

X-rays, I don't routinely insist upon when I do MSK MRI,

3:31

including the shoulder.

3:33

Sometimes they can be helpful,

3:34

but more often than that, I...

3:36

not...

3:36

I don't need them.

3:38

I may use an X-ray to look at cortical flakes,

3:41

strange changes in the growth plate

3:44

to look at bone stock in the glenoid rim.

3:47

I may use it to look at the

3:49

matrix of a bone lesion.

3:51

This is an example of little league shoulder,

3:53

or proximal humeral epiphysiolysis,

3:56

where the physis has gotten very wide

3:59

laterally in this condition.

4:02

Which I'm not going to cover today

4:04

only to say that the X-ray can't have a rule,

4:07

but it's not essential

4:10

in the interpretation of shoulder MRI.

4:12

And here, you can see that the MRI shows not only

4:16

exactly what the X-ray showed.

4:17

But it clarifies.

4:19

Some of you might have looked at this and said,

4:20

"Oh, that's a tumor."

4:21

No, it's not a tumor.

4:23

It's simply the growth plate widened

4:25

laterally due to failure of ossification.

4:28

And this occurs as a result of

4:31

repetitive metaphyseal insult

4:33

interrupting the metaphyseal blood supply,

4:36

and not allowing the proliferating cartilage to ossify

4:41

the cartilage cells stack up and you get a

4:43

very wide physis and you can have an

4:46

asymmetrically elongated shoulder.

4:48

So, let's turn our attention

4:50

now to the rotator cuff.

4:53

Part one, as we said we would,

4:55

there are two

4:57

basic types of tendons in the shoulder.

5:00

There are flat tendons,

5:01

supraspinatus and infraspinatus,

5:03

teres minor, and subscapularis.

5:05

And there are round tendons

5:07

like the biceps long head.

5:08

Let's start with the flat tendons.

5:11

We're going to focus on, first, tendon tear length.

5:15

Length is A to P,

5:17

anteroposterior to posterior

5:18

as depicted by our green arrow right here.

5:23

So this would refer to its completeness.

5:25

So we could have a complete A to P

5:27

tear of the supraspinatus,

5:29

we could have a complete A to P tear

5:31

of the infraspinatus, and so on.

5:33

Completeness is not synonymous with depth.

5:36

So you could peel off the whole under

5:38

layer from back to front,

5:40

and you would have a partial thickness complete tear.

5:44

Complete A to P.

5:46

Then you have width.

5:48

Some people refer to full-width retraction or retraction.

5:53

I like the term retraction or

5:54

mediolateral retraction.

5:57

So this would be a coronal projection.

5:59

This is depicted with our red arrow.

6:01

You're looking coronal here.

6:03

You're looking sagittal here.

6:04

So in the coronal projection,

6:06

you might describe in centimeters how

6:08

much retraction you have

6:10

or it's perfectly acceptable to say that you retracted

6:13

just medial to the acromioclavicular joint

6:15

and use some other anatomic reference.

6:18

Then you've got depth in blue.

6:21

Depth is very self-explanatory,

6:23

but we do break down depth into nominal

6:26

less than 25% percent.

6:28

25% to 50%,

6:30

greater than 50%,

6:31

and then near full depth,

6:33

as well as full depth,

6:34

and some of this is subjective.

6:37

But the majority of it,

6:38

you'll be able to visualize and analyze

6:40

in multiple projections.

6:42

Let's turn our attention to round tendons.

6:44

In a round tendon,

6:46

we have a somewhat different nomenclature.

6:48

Of course, if you rupture a round tendon,

6:50

that's pretty easy;

6:51

let's talk about partial thickness tears

6:53

of these round tendons. If these tears,

6:57

which can be quite laminar or linear,

7:00

go through two surfaces,

7:02

it doesn't matter whether it's A to P

7:04

or medial to lateral,

7:04

we call this a split tear.

7:07

If these laminar tears are interstitial,

7:10

we call them interstitial tears or

7:12

concealed interstitial delamination tears.

7:15

They can go in any direction.

7:17

If they are surfacing on one surface alone,

7:20

we call them surfacing delamination tears.

7:23

We don't use the term "split" here

7:25

unless two surfaces are involved.

7:30

Now, you can see that the subunits of

7:34

the tendon, the so-called fibrils.

7:36

The tendon's subunits may be spared,

7:39

and you may be tearing through the collagen

7:41

and the interstitium of the macro tendon without actually

7:46

affecting the subunits.

7:47

When the subunits are affected,

7:50

you can actually look inside the tendon

7:52

and you'll see these tendons do

7:54

a little dipity doo or bend,

7:56

and we call this tendon crimping.

7:58

You can also see tendon crimping positionally.

8:01

If you put the,

8:02

you know,

8:02

the arm in one extreme location or the other,

8:05

some tendons will tend to fold up.

8:07

So crimping is not necessarily pathologic,

8:10

but it certainly can be.

8:12

Crimping is just a synonym for

8:14

micro retraction or microfolding.

8:17

Here's a coronal diagram demonstrating

8:20

the supraspinatus rotator cuff with the bursa on top of it.

8:24

Here's the subdeltoid bursa.

8:25

Here's the subscapularis,

8:27

which is an up-and-down tendon

8:29

with its footprint.

8:30

Here's the rotator cuff with its footprint.

8:32

And we demonstrate for you the arc

8:34

shaped coracohumeral ligament,

8:38

which passes through this space,

8:39

known as the anterior rotator interval,

8:43

which contains the biceps right there.

8:45

The crossing over top of the biceps, and anterior to it,

8:49

and then becoming the undercarriage,

8:51

or underbelly of the rotator cuff

8:53

is the rotator cuff cable.

8:56

The cable is just a thickened condensation of the CHL.

9:01

When it's very, very wide medial to lateral;

9:04

we call that a cable-dominant cuff

9:06

and those are less likely to retract.

9:09

The thinner tissue lateral to it

9:11

is known as the rotator cuff crescent.

9:14

Here's a diagram demonstrating

9:17

the parallel subunits of the intra-substance

9:22

of the tendon. Here's the supraspinatus.

9:24

Here's its footprint on the humerus.

9:26

This is not an articular surface.

9:29

This is a humeral surface.

9:30

There's no cartilage here;

9:32

cartilage doesn't start till over here

9:35

and coursing underneath in the coronal projection is RC.

9:40

That does not stand for the rotator cuff;

9:42

that stands for the rotator cable,

9:44

which is coming from anterior to

9:47

posterior in an arc.

9:48

And more on that in a few moments.

9:52

And here is the very moment.

9:54

There's an axial projection on the viewer's left

9:59

demonstrating the supraspinatus,

10:02

and the supraspinatus can have several muscle subunits

10:06

and it can have several different tendon subunits.

10:09

Look at this very long tendon;

10:10

intermediate length tendon;

10:12

multiple short tendons.

10:14

So tremendous variability in the number

10:16

and length of tendons of every

10:19

single muscular structure.

10:20

Here's the infraspinatus with another interval,

10:23

the posterior interval in the back

10:26

between the supraspinatus and the infraspinatus.

10:29

Remember, there's also an interval in the front;

10:31

look at the sagittal projection for a minute.

10:33

Here is the subscapularis.

10:35

Here's a space or interval.

10:37

There's the supraspinatus;

10:38

so this would be the anterior interval.

10:41

This over here would be posterior interval.

10:43

The anterior interval is bounded,

10:45

as we said previously,

10:47

by the coracohumeral ligament.

10:50

Which continues on as the undercarriage

10:53

of the rotator cuff, the deepest layer.

10:56

And this is known as the rotator cuff cable.

10:59

Above it is the supraspinatus myotendinous unit.

11:03

Forms the anterior boundary of the

11:05

interval which houses the biceps tendon

11:08

and the superior glenohumeral ligament,

11:11

which forms a little sling underneath

11:14

it in the axial projection.

11:17

Just medial or medial to my blue arrow.

11:20

You can see this arc-shaped dark

11:23

condensation right here,

11:24

and you are seeing the rotator cuff

11:26

cable with my big fat arrow

11:30

right here,

11:31

covering the rotator cuff crescent

11:33

more peripherally.

11:35

And there is your posterior

11:37

interval space.

11:39

So let's turn away from the cable guy

11:41

now and go to another name game.

11:44

And we're going to look at the some

11:46

eponyms that we use to describe the

11:49

cuff. First, the footprint tear.

11:51

This is the footprint.

11:52

It is not articularly cited.

11:54

Tears here are obscured from view to the

11:57

surgeon, unless they pass

11:59

through the bursal surface.

12:00

That's why they're often referred to

12:02

as footprint concealed interstitial

12:04

delamination tears.

12:06

They may penetrate cartilage or bone.

12:09

And when they do,

12:10

this is referred to as a rim rent

12:12

phenomenon or rim rent extension

12:14

of that tear.

12:16

Sometimes you can have very tiny tears;

12:19

usually they emanate from the posterior

12:22

rotator interval between the

12:23

supra and infra.

12:25

And you get a small thin area of the

12:28

section of synovial fluid into

12:30

the myotendinous unit,

12:31

forming a cyst known as a

12:34

sentinel cystic tear.

12:35

You can have tears that involve the

12:38

articular surface right here;

12:39

they're very small,

12:40

they're under surface;

12:41

they're known as supraspinatus tendon

12:43

articular surface tears,

12:46

or STAS lessions.

12:46

You can have tears that involve the

12:49

footprint and tear off or

12:51

vuls and retract.

12:53

These are known as partial articular-

12:55

sided supraspinatus tendon avulsions.

12:58

You can have the same thing happen

12:59

upside down in the outer layer.

13:02

Then you can have an articular

13:04

surface tear,

13:05

so-called STAS type

13:06

lesion,

13:07

but now it has interstitial extension.

13:10

So we call that a partial articular-sided

13:12

tear with interstitial extension also known as a PAINT lesion.

13:17

Let's turn our attention now to the cuff zones.

13:20

As you all know,

13:21

tendons go

13:23

from muscle to bone; occasionally,

13:25

they'll go to other structures.

13:27

So on the bone side,

13:28

you've got tendon then muscle.

13:30

The muscle continues on,

13:31

then you have a myotendinous unit,

13:33

and then you have some

13:34

zones of the cuff:

13:35

medial to the myotendinous junction,

13:38

medial to the bare area,

13:39

at the level of the bare area,

13:41

and then the footprint,

13:43

and you have an upper footprint

13:45

and a lower footprint.

13:47

The upper footprint lateral to the bare

13:49

area. So some of you are saying, "Well,

13:51

what's the bare area?" The bare area

13:54

is an area right here that is devoid

13:56

of this blue highlight cartilage.

13:58

Now in children and young adults,

14:00

you don't have much of one;

14:02

but as you get older,

14:04

this pulls away a little bit and widens.

14:06

So it gets a little wider

14:07

when you're older,

14:08

and it's also wider in the back

14:11

than it is in the front.

14:12

So the bare area, devoid of cartilage,

14:15

enlarges with age,

14:16

and you'll see a little

14:17

fluid settle in here.

14:18

And a common mistake is to call that an

14:20

undersurface tear or a STAS

14:22

lesion.

14:23

More on that in a moment.

14:24

Another term you'll hear is the critical zone.

14:26

The critical zone is approximately ten

14:28

times medial to the footprint.

14:29

It encompasses the level of the bare area and

14:31

little bit of the area medial to

14:34

the bare area of the rotator cuff.

14:36

It is said that this is a weakened area

14:38

of the cuff where tears

14:39

are prone to occur.

14:40

That may be a little bit

14:42

of an overstatement.

14:43

And then, here you see on

14:45

the left-hand side

14:49

the cable dominant area of the cuff

14:51

and the crescent dominant area

14:52

of the cuff. And remember,

14:54

when the cable is very wide,

14:56

the tears tend to retract a bit less.

15:00

Here are some other

15:02

important descriptors that you may hear.

15:05

One of them includes a very thin tiny

15:09

pinhole-like configuration of the tear. It can

15:11

be straight. It can be circuitous. It can be partial depth. It can be full depth.

15:14

And I use the term pinhole tear,

15:18

which is my way of denoting

15:20

this is a tear that can potentially heal on itself and in

15:23

no way is associated with retraction.

15:26

These pinholes can go up and down.

15:28

They can go side to side.

15:29

So they can be vertical.

15:31

They can be horizontal.

15:32

A common tear is the teno-osseous avulsion

15:35

where you have not taken

15:36

a piece of bone,

15:37

just the tendon comes off the footprint. And

15:39

another phenomenon you'll encounter

15:42

is a ghost tendon

15:44

where the tendon just appears to

15:46

disappear. Where did it go?

15:49

It's often infiltrated by something;

15:51

most commonly in middle-aged women in

15:54

the left arm. Adhesive capsulitis renders

15:57

the tendon invisible unless

15:59

you perform the right sequence.

16:01

This can also happen with gout

16:02

and a few other phenomena.

16:05

So with the rotator cuff,

16:06

what's involved? We have a checklist.

16:08

We have the supraspinatus,

16:09

the infraspinatus, the subscapularis,

16:11

the teres minor, the biceps long tendon,

16:14

and the joint capsule including the CHL

16:17

or rotator cable.

16:19

We're going to look at length from A to P.

16:22

We're going to look at depth in percent.

16:24

Is it full depth? Is it partial depth?

16:26

How deep is it?

16:28

Retraction in centimeters or

16:30

based on anatomy. Eponyms.

16:32

The muscle. Is the muscle involved?

16:35

Is there fatty infiltration

16:37

of the muscle

16:38

and is it volumetrically compromised?

16:41

Other cysts, other signs of impingement.

16:43

Is there evidence of bursitis

16:45

or bursal fluid?

16:48

Let's take a start right here.

16:49

This is a very young individual.

16:51

So you can see hyaline cartilage is

16:53

present almost all the way to the

16:55

footprint; here is the footprint,

16:56

maybe just a tiny area devoid

16:58

of hyaline cartilage.

16:59

It's a little brighter over here.

17:01

That is totally normal.

17:03

Contrast that with this

17:04

younger patient where we do have a

17:07

little bit of a glow right here,

17:08

but look inside the tendon.

17:10

You see this and then

17:12

this and then this,

17:13

making a zigzag towards

17:15

the bursal surface,

17:17

but not producing any fluid

17:18

in the bursal surface.

17:20

And we would call this a circuitious greater

17:21

than fifty percent depth

17:23

pinhole-type tear.

17:26

Now remember.

17:26

We said you can have multiple muscles.

17:28

You can have multiple muscle fascicles.

17:31

You can have multiple tendons and

17:32

multiple tendon fascicles.

17:34

And then within...

17:36

within the tendon,

17:37

you have tendon subunits.

17:38

So you can look inside the tendon and

17:41

typically, when you look

17:42

inside the tendon,

17:43

you're going to have this

17:44

parallel phenomenon

17:45

where the subunit fibrils are going

17:48

to be parallel to one another.

17:50

In this case,

17:51

that is clearly not the case.

17:54

You can see the cable kind

17:56

of folded over on itself.

17:57

Everything looks interstitially

18:00

disorganized. On the T2 everything looks somewhat

18:02

black because there's a great deal of

18:05

fibrous tissue attempting to support

18:07

and replace the rotator cuff.

18:09

And I often use the term in a situation

18:12

like this confluent interstitial

18:14

tendinopathy with tendon fibril failure.

18:18

This is not dissimilar to what you

18:19

might see in adhesive capsulitis

18:21

or gout, the sort of disappearing tendon.

18:25

Except when you look through it

18:27

on the water-weighted image,

18:28

the tendon fibrils will be parallel.

18:30

They'll be separated from one another

18:32

due to the interstitial connective

18:35

tissue collagen infiltration,

18:37

but the fibrils will be preserved.

18:39

That's not present here.

18:41

This is a mechanical process

18:43

you are looking at. There's an example of

18:45

a patient with an articular sided tear

18:47

with interstitial extension medially,

18:50

a so-called partial articular side

18:52

of tear with interstitial extension

18:54

known as a PAINT lesion.

18:56

Let's compare this next case,

18:58

a patient with a bare area

19:01

devoid of hyaline cartilage

19:02

where fluid likes to settle.

19:04

The fluid is flat,

19:05

the fluid is homogeneous.

19:06

The parallel fibers of the tendon

19:09

and their thickness are preserved. No,

19:12

this is normal.

19:13

It is not an undersurface tear or STAS lesion.

19:15

This is. This is because it

19:18

makes a little mountain.

19:20

It pushes the tendon up.

19:22

It encroaches on the undersurface of the

19:25

tendon. Its heterogeneous internally.

19:27

STAS lession, normal on the viewer's left.

19:31

Now, this would have been a STAS lesion,

19:33

had it been over here

19:34

in the articular surface;

19:36

but it's not on an articular surface,

19:39

it's on the lateral shelf or

19:41

footprint of the humerus.

19:43

So here we don't use the term STAS lesion,

19:46

we call this a concealed interstitial

19:48

delamination tear.

19:50

If you went arthroscopically in,

19:51

you couldn't get to it.

19:53

You'd be blocked by this fiber.

19:54

If you went in this way,

19:56

you couldn't get to it.

19:57

You'd be blocked by the

19:59

superficial fibers.

20:00

And there is some bony

20:02

rim rent type extension

20:03

which is common in impingement syndrome.

20:06

Here is a pinhole tear, very very razor thin.

20:09

This one a horizontally oriented,

20:11

slightly circuitous up and down,

20:13

pinhole tear.

20:14

It perforates the bursal surface

20:17

also suddenly and produces

20:19

a little bit of bursal fluid as it

20:21

frequently does with some areas

20:24

of rim rent penetration.

20:26

You can see the subacromial

20:30

coracoacromial ligament

20:31

likely responsible for this

20:33

impingement syndrome.

20:35

Here's another example of a partial, a family of partial

20:38

thickness tears. There's the bare area. No,

20:42

that's not an undersurface tear.

20:44

This is an adult. Yes,

20:46

there's a tiny little slap lesion,

20:47

but over here is a bursal-sided tear

20:50

that is more superficially located.

20:53

And when they are more superficial,

20:56

they tend to have this sort of gull wing

20:58

paraglider type configuration.

21:00

There's a wing of the bird.

21:02

There's a wing of the bird,

21:03

superficially located.

21:04

There was no bursal fluid.

21:07

There were a few fibers on top.

21:09

But it was a partial thickness more

21:11

bursal sided tear demonstrating

21:13

that phenomena.

21:14

Here's another one right at the

21:16

posterior interval

21:17

supraspinatus-infraspinatus

21:18

conjoint region.

21:22

This is connective tissue right here.

21:24

And there's some bright

21:25

signal underneath it.

21:26

If you look very carefully,

21:28

there's a dot. No, that's not a vessel.

21:30

That's a little bit of synovial fluid

21:33

accumulating through a microscopic hole

21:36

and working its way out of that

21:39

hole slowly over time.

21:40

It's a little easy to see in the

21:42

substance of the conjoint right here.

21:45

And then when you look more medially at the

21:48

infraspinatus myotendinous junction

21:51

which is where the majority of

21:53

these occur, by the way,

21:54

much more common than the other

21:56

rotator cuff tendons,

21:57

you see the myotendinous

21:59

unit has a friend,

22:01

and the friend is this pseudo-cyst which

22:04

arose from the rotator cuff perforation

22:07

at the rotator posterior interval. Now,

22:10

if you give this to a pathologist,

22:12

this sentinel cystic delamination tear is

22:16

identical histologically

22:18

to a ganglion pseudocyst,

22:20

and it is identical to a paralabral

22:23

cyst. So these are radiologic diagnoses.

22:26

You make a huge difference in the words

22:29

you use when chosen properly

22:32

or improperly.

22:34

Here is a PASTA lesion

22:36

with the eponym defined

22:37

above. There's the outer shell of the

22:41

PASTA. There's the undersurface of

22:43

the PASTA. In this 32-year old

22:45

professional football nose tackle

22:47

three hundred pounds,

22:49

the cuff is a little thin for

22:51

three hundred pounds.

22:52

And where is the undercarriage of

22:55

the cuff and the rotator cable?

22:57

It is over here. Right there,

23:00

retracted as the deep portion of the some

23:03

which has come off the footprint and

23:05

now is located medially. There

23:07

it is again.

23:09

He had the same thing in

23:10

the opposite shoulder.

23:12

He played a full season with both of

23:15

these partial thickness tears,

23:16

although not effectively.

23:19

And eventually the right one completely

23:21

ruptured; he had surgery.

23:23

And unfortunately,

23:23

it was a career-ending thing for him.

23:26

He was an all-pro,

23:27

I think, six or seven years in a row.

23:29

One of the best nose tackles

23:31

in all of football.

23:33

Here's another example of an eponym.

23:36

This is a footprint avulsion tear.

23:38

The T1, not so informative;

23:41

but certainly

23:42

the T2 and proton density water-weighted

23:44

fat suppression image in the middle

23:47

shows the stubby rotator cuff,

23:49

and then it doesn't fan out and attach

23:52

to the shelf of the humerus.

23:54

It's torn and just kind of hanging

23:56

right there like a hanging chad,

23:58

and there's some fluid underneath it,

24:01

behind it, and through it,

24:03

a rotator cuff footprint avulsion tear.

24:07

There it is in the sagittal projection.

24:08

All of this tissue should camp right

24:11

down on the anterior surface

24:13

of the humerus.

24:14

There's a pitfall and avulsion of the

24:17

rotator cuff demonstrating a wide

24:20

tear from here to here.

24:22

So if we were going to measure it,

24:24

I'd measure it there and there,

24:26

I get about two centimeters.

24:27

I usually add a centimeter for the

24:31

curvature of the humeral head,

24:33

so about a three-centimeter tear,

24:34

and some of you are saying to yourself,

24:36

"Well,

24:37

what is this thing? Isn't that

24:38

a little bit of rotator cuff tendon?"

24:40

Yeah, it is. It's a shard of the tendon,

24:43

and it's completely broken free.

24:45

It's not attached to anything.

24:46

It's just floating in the hole.

24:49

So for all intensive purposes,

24:51

it is debris filling the hole, producing

24:55

a pseudo-tendon, if you will.

24:58

Here is a subscapularis tear.

25:01

These are a little bit different.

25:04

The subscapularis runs from superior to

25:07

inferior. So it's also a flat tendon,

25:11

and it has an upper fiber

25:13

that is mostly tendinous,

25:15

then a second group of fibers that

25:18

are tendinous and muscular,

25:20

a third group that are tendinous and

25:21

muscular, and then the fourth group,

25:23

the lowermost portion of the

25:26

subscapularis. This portion right here

25:27

where my pinky is mostly muscular.

25:30

When this tears,

25:31

it can easily be confused

25:33

with a teres major

25:34

or latissimus dorsi tear.

25:36

The subscapularis is very weird because

25:39

it sends fibers over with the transverse

25:41

ligament over here.

25:43

It sends fibers to the

25:45

lesser tuberosity.

25:46

It has a high propensity to tear

25:49

interstitially, which it has done.

25:51

Here are some of the deep lesser

25:53

tuberosity fibers.

25:55

The superficial fibers have separated

25:57

from the deep fibers,

25:59

allowing the poor unfortunate fat swollen

26:02

and interstitially torn biceps to

26:05

migrate interstitially into the waiting

26:08

arms like a fish mouth

26:10

of the subscapularis.

26:11

And this is the most common type of

26:14

biceps pully mechanism, biceps dislocation

26:18

subscapularis tear. Occasionally,

26:20

the biceps will dislocate on top.

26:23

Sometimes, it will dislocate underneath.

26:24

You might say, "Well,

26:25

how does it get underneath?"

26:27

The subscapularis comes off, the biceps

26:29

dislocates into the joint,

26:31

the subscapularis reattaches itself

26:33

as if it's never left.

26:35

And you're sitting there wondering how in

26:37

the world the biceps make it inside the

26:40

joint. Here's a bit easier one.

26:42

Here's the subscapularis.

26:43

It should be a nice flat fan shaped

26:47

attachment to the lesser tube.

26:48

It's not.

26:50

And the entire subscapularis is

26:52

off all the way from the top,

26:54

all the way to the bottom.

26:56

And here's a coronal projection

26:58

showing you a big hole which is

27:00

this white area right here.

27:02

And if we outline the hole like this,

27:05

some people say it's analogous to the

27:07

state of Nevada or an earlobe.

27:10

I don't think it really looks

27:11

much like an earlobe.

27:13

But here are the subscapularis fibers

27:15

and when they rupture,

27:16

they tend to float upward in

27:19

an acromial orientation.

27:21

There's another rotator cuff tear with

27:23

a very low line acromion and a thick

27:26

coracoacromial ligament,

27:27

resulting in impingement syndrome.

27:29

And there is your rotator cuff.

27:32

The mediolateral dimension

27:33

is right here.

27:34

You'd have to measure the length

27:37

in the AP projection.

27:39

But you can see how tight this space is

27:42

and when the patient picks their arm up,

27:45

the spur impacts that spur and just

27:48

is ruinous for the rotator cuff.

27:50

Let's skip over this slide,

27:52

and that prior slide is an illustration

27:55

in the axial projection of what

27:57

I'm about to show you now.

27:58

This is another axial projection at the

28:02

top of the shoulder demonstrating

28:04

one of the cardinal orthopedic shapes of

28:07

rotator cuff tears called the

28:09

L or upside-down L shape.

28:12

So this is a big fat hole looking from

28:14

the top down. Why do we want to do this?

28:17

We want to do this because

28:19

this is how the orthopedic

28:20

surgeons see the tear.

28:21

This is how you see the tear in the

28:23

sagittal projection. Here's the tear,

28:25

here's the tear, here's the tear,

28:27

very different.

28:28

But when you look at it

28:29

like the surgeon does,

28:30

you have a much different perspective.

28:32

Now,

28:33

there are a couple of other shapes that

28:34

the surgeons are fond of and

28:37

like you to describe.

28:38

One is the C-shaped tear,

28:40

I'm going to show you one

28:41

in a few minutes.

28:42

Another one is the U-shaped tear,

28:44

right there.

28:45

Now, why,"Why is this important?",

28:48

somebody asked previously, because the

28:50

surgeon does not want to... Let me see

28:52

if I can get my colors here.

28:54

The surgeon does not want to go in and

28:56

do this. They don't want to take this

28:58

and sew it back over here.

29:00

If you do that,

29:01

you're going to overstretch the cuff.

29:02

That is what's called the

29:04

non-anatomic repair,

29:06

and it's not going to hold.

29:07

So they have to have an excellent three-

29:09

dimensional top-to-bottom

29:11

perspective of the tear.

29:13

So what they actually have to do is

29:15

interpose the tear like this,

29:17

like closing the zipper on a pair of pants,

29:19

and then they may tug it

29:21

over a few millimeters

29:22

and sew this reposition from A to P

29:25

back to its position over here. So again

29:28

the goal

29:30

of the repairs, an anatomic repair,

29:31

and the best way to do that is to

29:34

understand the shape in

29:35

the axial projection.

29:36

So don't ignore the axial projection

29:39

in your assessment of these tears.

29:42

Here's a massive rotator cuff tear. T1, T2, PD, FAT, SAT.

29:48

And there's a giant hole in the rotator

29:50

cuff. Some of you may be saying, "Well,

29:52

really, what's that?

29:54

Isn't that a piece of tendon?" No.

29:55

That is the delaminated deltoid.

29:58

The patient has a basically lost

30:00

their acromion. It's been eroded.

30:02

They have no rotator cuff, no supra, no infra, no teres,

30:05

no subscap.

30:06

The only thing left holding a shoulder

30:08

together is the deltoid and it fails,

30:11

the deep fibers flop down into the hole

30:14

and simulate rotator cuff tissue

30:16

which is most unfortunate.

30:18

There's a coronal projection of another

30:20

massive tear. When do we use the term

30:22

massive? Complete, full thickness, retracted, multi-tendon tears.

30:27

Here's the humeral head, no longer

30:29

centered with the glenoid.

30:31

It's bouncing up.

30:32

It's produced auto-acromionectomy

30:34

and in abduction.

30:36

This friction phenomenon has produced a

30:39

giant intraosseous ganglion

30:41

of the greater tuberosity.

30:43

No, it's not a tumor.

30:45

It's a bone and pseudo cyst,

30:46

very analogous to the ganglion that

30:49

you see in the soft tissues.

30:52

Let's turn our attention now to impingement.

30:55

I break impingement down after my

30:58

thirty-five to forty years in this field

31:00

into biomechanical and anatomic

31:03

impingement.

31:04

Biomechanical, usually young individuals

31:05

under age thirty.

31:08

Anatomic impingement,

31:09

older individuals.

31:12

Older, older's probably over ninety.

31:13

But let's call older for

31:15

today over fifty.

31:16

And then you've got mixed biomechanical

31:18

and anatomic impingement in people

31:20

between thirty and fifty.

31:22

So biomechanical impingement:

31:24

internal impingement, cocking

31:26

and external rotation,

31:27

so called a bear near impingement

31:30

position,

31:30

like Sandy Koufax at the beginning

31:33

of the throwing motion.

31:35

And you have a posterior triad of posture,

31:38

superior labrum, infraspinatus,

31:40

and bony pitting.

31:41

You have the same thing in the front

31:44

with the mid phase or follow-through

31:47

biomechanical dysfunction in the

31:50

overhead throwing or javelin-throwing

31:52

motion.

31:53

Then you've got the older group of

31:55

individuals in which the impingement

31:57

is surely or mostly anatomic

31:59

because you're just not as vigorously active.

32:02

And this includes almost exclusively the

32:05

acromion and the coracoacromial ligament,

32:07

although occasionally, the coracoid can

32:10

produce abutment or impingement and rarely

32:13

the acromioclavicular joint.

32:15

So here is an example of a young man

32:17

played for the New York

32:18

Yankees Professional

32:19

American Baseball Team sent down to the

32:22

minor leagues for some rehabilitation.

32:24

Somebody at the local large university

32:27

hospital said the patient was a

32:29

dislocator. Well, he's not a dislocator.

32:32

But they thought that because of this

32:33

huge trough in the labrum. But in fact,

32:36

this is what overhead athletes get due

32:39

to repetitive external rotation

32:41

abduction positioning.

32:43

They get impaction-related troughs and

32:45

these troughs and pits eventually

32:48

evolve into pseudocysts.

32:50

The infraspinatus is frayed.

32:52

There's the fraying right there.

32:54

There's the fraying right there.

32:56

And here's a swelling of

32:57

the infraspinatus,

32:58

a swelling of the posterior labrum.

33:00

All part of the triad of internal

33:03

impingement syndrome due to biomechanical

33:06

assymmetry of musculature during

33:08

the overhead throwing motion.

33:11

The reader also said that the labrum

33:13

was too big. It was fragmented.

33:15

None of those were true.

33:17

You do get labra that are big,

33:19

but they're not too big for

33:20

a professional thrower.

33:21

The labra do get very big.

33:23

The ligaments hypertrophy a bit,

33:25

and it's very common to see this very

33:28

irregular pitted appearance within the labrum.

33:31

Some people refer to this as

33:33

degeneration. Most of the time,

33:34

this is related to dystrophic CPPD.

33:38

In contrast,

33:39

here is somebody with biomechanical

33:42

decentering of the humeral head

33:44

during the throwing motion.

33:45

The acromion is fine.

33:47

The ligaments are fine.

33:48

There's nothing anatomically wrong.

33:50

It's a biomechanical problem. And anteriorly,

33:53

the patient through friction and

33:55

genetics has developed hydroxyapatite

33:57

deposition disease or HADD as a

34:00

manifestation of their external

34:02

impingement.

34:03

Now let's turn our attention to

34:05

anatomic impingement.

34:06

This is a person fifty-two years of age.

34:08

There is a large rotator cuff tear.

34:11

You can see one end of the cuff right

34:13

here. It should have attached over here.

34:16

And it's a result of this Kell-like

34:20

acromion. In the axial projection,

34:22

look right there.

34:23

There is your rotator cuff cable.

34:25

It's a little bit C-shaped. In

34:28

here's your crescent-shaped hole.

34:30

So this is a crescent-type tear seen in

34:33

the axial projection with a Keel-like

34:36

acromion producing subacromial

34:38

outlet-related impingement. This time,

34:41

the impingement is ligamentous.

34:43

No, that is not a spur.

34:46

Even though it's dark,

34:47

ligaments are dark also. Cortex is dark.

34:50

But you'll be able to follow this right

34:52

across the anterior shoulder to the

34:54

coracoid, so there it is, there it is,

34:57

there it is, there it is.

34:58

And your saying to yourself,

34:59

"But the tendinopathy is over here,

35:02

and the ligaments over here.

35:04

The pseudocyst from friction is over

35:06

here, but the ligaments over here.

35:08

But what about when you

35:09

pick your arm up?"

35:11

When you pick your arm up,

35:12

the tendon rubs against this thick

35:14

hypertrophied ligament.

35:15

There's the rest of the ligament as it's

35:17

starting to make its way

35:18

over in this direction,

35:19

and the cuff is just getting

35:21

hammered by that ligament,

35:23

and the interstitium of it is demonstrating

35:27

disorganization and interstitial tendon

35:29

fibril failure with pitting of the

35:32

humeral head. In the sagittal projection,

35:35

there's your CAL anteriorly.

35:38

And if you sit back for a minute

35:39

and just stare at the screen,

35:41

you see there is a very slight

35:43

depression on the rotator cuff.

35:45

Even though this patient doesn't

35:49

have their arm up.

35:50

So the arm is at the side in

35:51

the neutral position, yet

35:53

the patient still demonstrates this

35:56

pressure on the rotator cuff.

35:58

Let's skip over the different

35:59

types of coracoacromial ligaments.

36:00

Here is one that is bony with

36:03

a pincer-like architecture.

36:05

There is a spur from the

36:08

greater tuberosity.

36:09

A spur from the acromion.

36:11

You pick your arm up and you get spur on spur

36:15

and this pinch the rotator cuff and reduce it

36:17

just to a thin thread and essentially

36:20

full-thickness rotator cuff there.

36:23

Now,

36:24

the subscapularis is a

36:26

thing unto itself.

36:27

These are rather painful tears

36:29

even when they're small.

36:30

There is no good measurement for the

36:33

coracoid distance to the humerus.

36:35

So I just simply look at the tissues

36:37

underneath, and they look horrible.

36:38

I can't even find the biceps.

36:41

I don't see the fibrils of the

36:43

subscapularis, except this one.

36:45

It's just one big puffalump.

36:47

And the reason is when the patient

36:50

internally and externally rotates

36:53

the shoulder, look at the spur extending

36:55

off the humerus bangs

36:57

into the coracoid,

36:59

crushes the subscapularis in this

37:01

example of coracoid abutment

37:04

or impingement syndrome.

37:06

And as mentioned, you know the subscapularis

37:09

is rather complex.

37:10

It has four layers from top to bottom.

37:13

Its footprint is shaped like

37:14

the state of Nevada.

37:16

And it has fibers that go over the top of the

37:18

biceps contributing to the transverse

37:21

ligament with the pectoralis major

37:23

tendon and the greatest

37:24

contribution made by the coracohumeral

37:27

ligament and most of the footprint is

37:30

on the lesser tuberosity.

37:32

Let's turn our attention

37:33

now to the labrum.

37:35

We're going to look at the shape and

37:37

conformity and orientation

37:38

of the labrum.

37:40

We're going to look at microinstability

37:41

lesions and macroinstability lesions.

37:43

Those are associated more

37:46

frequently with dislocation.

37:47

And then we're going to look at inferior

37:51

labroligamentous injuries.

37:52

If we have time,

37:53

we'll talk a little bit about the

37:55

MGHL and SGHL. I'll just grab a little water.

38:01

So when you look at your

38:03

shoulder initially,

38:04

you'll tend to look at the T1

38:06

which is very anatomic. This also helps

38:08

you see fractures if you've got a

38:11

dislocated shoulder. Usually fractures at

38:13

the apex are not Hill-Sachs lesions.

38:16

They tend to be more related to SLAP

38:18

lesions. Most Hill-Sachs lesions are just

38:20

slightly off to the side at the eleven

38:22

o'clock position on the right,

38:24

at the one o'clock position on the left,

38:27

and most impingement-related troughs are

38:29

found very eccentrically

38:31

off to the side.

38:33

And this is pretty helpful in your

38:35

analysis of the shoulder skeletal

38:37

anatomy and dislocators.

38:41

So don't be scared by these diagrams

38:44

which show you double lesion, triple lesion,

38:45

Bony Bankart, Classic Bankart,

38:47

and single lesion or Perthes lesion.

38:50

Let's take another tact.

38:53

I'm not so interested in all of you

38:55

mesmerizing eponyms right now.

38:57

The tact we'll take is anatomy.

38:59

The capsule in green is attached to the labrum.

39:02

The labrum is attached to the glenoid.

39:05

The glenoid and labrum are attached

39:07

to the hyaline cartilage,

39:08

and the glenoid and the capsule are

39:12

attached to the periosteum.

39:15

If you just go down this checklist of

39:18

anatomy structures and describe

39:20

what's wrong, you really

39:21

don't have to memorize.

39:22

But let's just take an example

39:24

of two or three of these,

39:26

the Classic Bankart. In the Classic

39:29

Bankart, you have torn the labrum,

39:30

you have torn the periosteum. So we got

39:32

at least two things going on.

39:36

Now, in the typical double lesion,

39:37

we also have two things going on.

39:39

But this time, it's not a periosteum.

39:43

It's the capsule has separated from the

39:45

labrum and the labrum has separated from

39:46

the glenoid. Don't worry about it.

39:49

It's just the name,

39:50

two things going on here.

39:51

Two things going on here.

39:54

We've got a Bony Bankart. That's pretty easy,

39:56

just goes through the bone and produces

39:58

bleeding or fracture of the periosteum.

40:00

No problem there.

40:02

And then we've got this weird lesion

40:04

where the labrum has come off the

40:07

glenoid, but the periosteum is not torn,

40:09

it simply elevates.

40:10

So this is known as a single

40:12

lesion or Perthes lesion.

40:13

It can occur in the backward.

40:15

It's called the reverse Perthes lesion.

40:17

And some people refer to

40:19

that as a Kim's lesion.

40:22

Here are a few other examples

40:24

of lesions that can occur.

40:26

One I do want to point out is detachment of

40:28

the labrum with periosteal elevation

40:30

where the labrum tumbles medially and inferiorly

40:34

under the periosteum,

40:35

gets trapped underneath it.

40:36

This is known as the anterior labral

40:40

periosteal sleeve avulsion injury.

40:40

This one I'm going to show you

40:41

separately all by itself in a minute.

40:46

And this one I'm not so concerned about.

40:49

So let's take a look at an example

40:52

of an ALPSA lesion.

40:54

This is a patient with shoulder

40:56

dislocation. And remember,

40:57

the labrum is going to tumble medially.

41:00

So you may see it in the axial,

41:01

but it's also going to tumble inferomedially

41:04

in the axillary region.

41:05

And here is the labrum.

41:08

These are shards and fragments of periosteum that are

41:12

holding the labrum in place.

41:14

Inferiorly,

41:15

the labrum itself is somewhat fractured

41:17

looking. And normally,

41:19

the labrum would be over here. With

41:21

the labral ligamentous complex

41:22

looking something like this.

41:24

And of course, it doesn't look that way.

41:26

And there is the typical Hill-Sachs

41:28

fracture. It's not at the apex,

41:30

it's at the eleven o'clock position,

41:32

and unlike, say, pseudocysts which are chronic

41:36

due to friction and irritation,

41:38

there are microtrabecular fractures

41:40

under the depressed fracture

41:43

telling you that this is an acute major

41:46

traumatic event in the axial projection.

41:49

There is a paucity of labral tissue

41:52

where it should be. Normally,

41:53

it should be right here,

41:56

and instead, it's over here.

41:58

And this little linear black thing right

42:00

here is the periosteum keeping it in

42:03

place along with some of the fibers of

42:06

the subscapularis and the MGHL. So the labrum is

42:09

trapped medially and inferiorly.

42:12

And if we look at the sagittal projection,

42:14

we've got some nice labrum right here

42:16

and some nice labrum right here,

42:19

but right in between where the yellow

42:22

arrow is we're a labrum...

42:23

we've got no labrum.

42:25

And that's where the labrum tore off, is

42:28

disappeared and is ghosted and is medialized

42:31

in this ALPSA lesion.

42:34

Another interesting lesion that you may

42:36

see and hear about is the ALIPSA or POLPSA lesion.

42:41

In this scenario,

42:43

you get capsular detachment the

42:46

periosteum may elevate a bit.

42:48

And this is known as a posterior

42:50

labrum intact

42:52

periosteal sleeve or capsular

42:54

periosteal sleeve avulsion.

42:56

You'll hear the term "POLPSA" used. In the

42:59

front it's called an ALIPSA lesion.

43:02

Let's look at this rather complex case.

43:05

Don't get scared,

43:06

no matter what country you are in,

43:08

no matter what time zone you are in,

43:11

we can do this together.

43:13

I don't care if you eponym this

43:15

until kingdom come.

43:16

What I care about is the anatomy.

43:20

Let's look together.

43:21

Here is the posterior capsular

43:24

ligamentous complex, called the PIGHL.

43:28

This can contract and get scarred and

43:31

troughs more on that a little bit later.

43:34

But let's follow the capsule around.

43:36

Keep going, keep going, keep going.

43:38

Stops.

43:39

The capsule is torn away from the

43:42

labrum, number one. How about the labrum itself?

43:44

It looks like mashed potatoes,

43:46

doesn't it?

43:47

It doesn't have a nice triangular shape,

43:49

so there is a complex labral tear.

43:51

That gives us number two.

43:54

Then the labrum relationship to

43:56

the glenoid is disrupted,

43:57

so there's labral glenoid detachment, number

44:00

three. The periosteum it wiggles,

44:02

it squiggles, and then it stops.

44:05

It's fragmented right there, number four.

44:07

There's another piece

44:10

of the detached periosteum.

44:12

How about the skeleton? It's bent backwards

44:16

and slightly regular in contour, number five.

44:21

Oh, we're not done yet.

44:22

What about the hyaline cartilage?

44:24

Looks terrible here and here,

44:26

But especially right there, number six.

44:29

So all in all,

44:31

we have six abnormalities

44:32

in this patient.

44:33

Not to mention the fact that the humeral

44:36

head looks like it's bouncing

44:37

off the back or

44:39

it's sagging posteriorly in the space

44:41

with posterior glenoid

44:42

deficiency syndrome.

44:44

And if we draw a line along the scapular

44:46

spine and a line perpendicular to that,

44:49

and then draw a line from the bony

44:51

labrum to the bony labrum,

44:53

we get an angle called the

44:54

retroversion angle

44:55

which normally is about three to six

44:57

degrees. This one is about fifteen degrees.

45:01

So we've got an abnormally retroverted

45:04

non-conforming glenoid.

45:06

What do I mean by non-conforming?

45:08

The humeral head should be perfectly in

45:11

the goblet of the cup. And it's not.

45:14

It is sagging posteriorly.

45:16

It's decentered in this patient with

45:18

posterior glenoid deficiency syndrome.

45:20

Here's the anterior labrum.

45:22

It's not uncommon to have clefts or

45:25

recesses in the anterior labrum between

45:28

the labrum and the glenoid.

45:30

So if I just saw that I wouldn't mind,

45:32

but I do mind the appearance

45:34

of the periosteum.

45:35

I do mind the separation of the

45:38

capsule from the labrum.

45:39

So that is very problematic.

45:42

But let's set that aside for a minute,

45:44

or even set aside the large effusion.

45:46

And let's keep going. As we come down,

45:48

the labrum should get bigger,

45:49

it should get blacker in the front,

45:51

and it does get a little bigger.

45:54

It doesn't get a lot blacker.

45:55

And we have this disorganized

45:57

periosteum right there.

45:58

You've got this capsular separation

46:00

from the labrum, right there.

46:01

So we have a very complex problem.

46:03

Let's keep going down.

46:04

It's getting bigger.

46:05

It's getting a little bit blacker. Well,

46:07

that's okay. This looks terrible.

46:09

That looks terrible.

46:10

The capsule looks terrible.

46:11

And then on the next cut,

46:13

just to help you with a sign.

46:15

It's not getting bigger and blacker.

46:17

It gets smaller and more

46:19

fissure looking,

46:19

so it's violating a very

46:22

serious cardinal rule.

46:24

And it's getting grayer and blobbier

46:27

and fluffier. If you will,

46:29

even though those aren't

46:30

scientific terms.

46:31

You have periosteal fragmentation,

46:33

you have labral fragmentation,

46:35

you have capsule detachment,

46:37

and then it starts to look

46:38

a little better,

46:39

even though it's not really attached

46:41

anymore. It gets a little blacker.

46:43

So that rule as you go from high to low,

46:45

the labrum should be a more consistent

46:48

nice black triangle with a labral

46:51

ligamentous attachment,

46:52

you know, nice and flush right on top of it or at

46:55

least medial to it. But flush with it.

46:58

This patient does have a partial rim tear

47:01

posteriorly with a little bit

47:03

of periosteal elevation, a posterior Perthes,

47:05

or reverse Perthes lesion to boot,

47:08

also known as Kim's lesion.

47:11

Here is a typical Bony Bankart. This

47:14

patient has a huge Hill-Sachs

47:16

lesion. You could measure it.

47:18

This one is about twenty-four

47:20

to twenty-six millimeters,

47:21

let's say, for example

47:23

from there to there.

47:25

And then, you would look over here and you see

47:26

this huge glenoid fracture. So any time

47:30

you have these two together like this,

47:32

you call this a bipolar lesion.

47:33

And then your next job is to determine

47:37

whether you have on-track

47:38

or off-track morphology,

47:40

meaning that the patient off-track is at

47:43

risk for repeated engagement and

47:45

repetitive spontaneous

47:47

passive dislocation.

47:49

You can learn more about this by turning

47:52

your attention to an article in the AJR

47:55

by Gyftopoulos and others

47:57

and Beltran and you'll be able to make

48:00

these measurements, if you want.

48:01

But generally,

48:02

if I have a shoulder with a Hill-Sachs

48:05

that approaches twenty-six millimeters

48:07

in length and I have lost more than

48:10

twenty-five percent of my

48:11

glenoid in the front,

48:13

my bony glenoid in the front or

48:16

my glenoid is not pear-shaped,

48:18

here's the pear. Normally,

48:20

the glenoid should look like this,

48:23

a little wider at the bottom,

48:24

a little more narrow at the top.

48:26

I'm trying a very good pear,

48:28

here's a pear.

48:30

But this one has an upside-down pear,

48:32

it's tapering at the bottom,

48:34

so pear-shaped labrum that's inverted,

48:36

greater than twenty-five percent loss

48:39

in the front with a Hill-Sachs that

48:42

approaches twenty-six millimeters.

48:43

There's a pretty good chance that I have

48:46

somebody who is a recurrent dislocator.

48:48

And do learn more about on-track,

48:51

off-track measuring with that article

48:53

that I gave you as a reference. There's

48:56

a big Hill-Sachs lesion,

48:57

there it is in the coronal projection at

49:00

the eleven o'clock position. There it is

49:02

with flatting in the sagittal position,

49:05

showing you typical architecture of

49:07

Hill-Sachs with the microtubecular

49:10

fractures underneath. Even though

49:12

this one is well-defined,

49:14

with sclerosis like you might see in the

49:16

trough of an impingement lesion,

49:18

you don't see these micro fractures

49:21

underneath when somebody is an impinger.

49:24

It's simply a low-grade repetitive

49:26

friction phenomenon. This one is huge;

49:29

it's markedly depressed.

49:30

And now you have to chase down what

49:32

the status of your glenoid is.

49:34

Let's look at some lesser labral

49:36

lesions, like the GLAD, the GARD, the Perthes,

49:38

and the Bennett lesion. First,

49:40

the GLAD lesion, a partial rim tear.

49:43

There's the partial rim tear,

49:45

doesn't come out the front,

49:47

and it does not affect the

49:49

periosteum. There's the diagram of it.

49:51

This can occur in either a

49:54

macroinstability dislocating shoulder

49:56

or a microinstability shoulder

49:58

where the patient reports clicking

50:02

that occurs,

50:03

and then their discomfort gives way

50:06

as soon as the click is over.

50:08

This is an abduction external rotation

50:11

position which often highlights with

50:13

a little bit of arthrography,

50:15

the labrum called the ABER view, ABduction

50:18

External Rotation.

50:20

Here's another either micro or macro

50:22

instability lesion called the "GARD"

50:24

lesion, a Glenoid Articulation Rim Divot.

50:28

This one dissects into the base of the labrum

50:30

and is starting to detach it from the

50:33

posterior aspect of the glenoid.

50:34

Now normally,

50:35

there is a little bit of

50:36

a ridge right here,

50:38

and in many individuals in

50:40

this very center of the glenoid,

50:42

not the case here,

50:43

you'll sometimes apt to

50:45

see a little notch here,

50:46

and that's known as the notch of Osaki.

50:49

But the notch of Osaki is never

50:51

accompanied by underlying edema;

50:52

it should be right smack dab in the

50:55

center. This is not the notch of Osaki.

50:57

This is a true divot in the glenoid.

51:00

Another labral lesion

51:02

which is more commonly seen in

51:05

microinstability, without dislocation

51:07

the macroinstability, is the Perthes

51:09

lesion. So here's your capsule, and there's your capsule,

51:12

capsule, capsule, capsule.

51:14

And now the capsule is flush on the base

51:17

of the labrum. That's normal,

51:18

even though it's distending.

51:20

There's your detached labrum.

51:22

There's your separation from

51:24

the underlying glenoid,

51:25

just a little bit of periosteal elevation.

51:27

So this would be your single lesion or your

51:31

Perthes-type lesion in the back,

51:33

the reverse Perthes lesion.

51:35

Here's an example of somebody

51:37

with functional instability.

51:39

This patient started out with a GARD lesion,

51:41

a lesion that looked like this

51:43

and then this piece swung forward

51:45

like a gate. There's the piece.

51:47

So when they internally

51:49

and externally rotate,

51:50

they have the sensation of locking the

51:52

shoulder, feels like it gives way;

51:54

but it does not dislocate,

51:55

and it doesn't truly lock.

51:57

This is the phenomenon of

51:59

functional instability.

52:00

Now sometimes when patients have

52:03

posterior glenoid deficiency syndrome,

52:06

it will suck the capsule into the joint.

52:08

So the capsule will do something like

52:10

this. It will come around, then

52:11

it will go like this.

52:12

It will make like a pseudo mass, and then

52:15

it will continue on this way.

52:17

It looks a little bit like what we call

52:18

the GLOM sign or the Glenoid Labrum

52:21

Ovoid Mass that you see with large

52:24

dislocations and tissue that swirls

52:26

around the detached labrum.

52:28

This sucking in of the anterior capsule

52:31

which can cause locking of the shoulder

52:33

is known as capsular intercalation,

52:36

another cause of functional instability.

52:40

Let's turn our attention

52:41

now to the famous and most important

52:44

inferior glenohumeral ligament

52:46

which is responsible for most of the

52:48

antero-inferior shoulder stability.

52:50

We got HAGL, BHAGL, AIGHL, RHAGL, GAGL,

52:52

and then some others for you here.

52:54

We're going to focus on these top six

52:55

and we're referring to the relationship.

52:59

Again, life's about relationships, so

53:01

is the IGHL,

53:02

the relationship of the IGHL

53:04

to the glenoid and the

53:09

relationship to the humerus.

53:10

So if we detach from the humerus, we call that a humeral avulsion of the glenohumeral ligament or HAGL.

53:13

If we take a piece of bone with it, right

53:19

there as we have, and it's retracted,

53:22

we call that a Bony HAGL.

53:24

If we tear on both sides,

53:25

we call that an anterior-inferior glenohumeral ligament tear

53:30

or Floating IGHL or AIGHL.

53:31

If it happens in the back,

53:33

it's a reverse HAGL or RHAGL.

53:35

If it happens on the glenoid side,

53:37

then it is a GAGL.

53:41

And you've already seen detachment of the labrum,

53:42

getting stuck underneath the periosteum

53:44

in the entity of the anterior labral

53:47

periosteal sleeve avulsion.

53:48

Let's look at some anatomy together.

53:51

Let's start out with the axillary

53:53

band of the IGHL.

53:55

There are three official bands.

53:58

But there's also a very far posterior

54:00

band that blends with the capsule that

54:03

is important in throwing athletes. Let's

54:05

focus on the three major bands. Here's

54:07

the axillary band distended by fluid. You

54:10

could see the continuity of the labral

54:13

ligamentous complex. You can't

54:15

really separate them.

54:16

And the nice broad footprint attachment

54:19

of the ligament of the axillary band of the

54:22

IGHL. Here's the posterior band

54:25

labral ligamentous complex; it comes

54:27

around and attaches to the humeral neck.

54:29

There's the anterior band; it's shorter,

54:31

it's stubbier as it should be,

54:34

it's got a very broad footprint and you

54:36

cannot really separate the labrum from

54:38

the IGHL very well in most cases.

54:42

So here's an example of somebody that

54:43

has detached the IGHL from

54:45

the humeral neck,

54:47

the so- called HAGL or humeral avulsion

54:50

of the glenohumeral ligament.

54:52

Here's one that is severely diseased.

54:54

You've detached the labrum

54:55

from the glenoid.

54:56

You've detached the ligament

54:59

from the labrum.

55:00

And this would be a GAGL, a glenohumeral

55:03

avulsion of the glenohumeral ligament, or a

55:06

GAGL-like lesion on the glenoid side.

55:08

Then it can happen right in the center

55:10

of the IGHL, as it has right here,

55:13

or you can have both the humeral side.

55:17

There's the humeral side. Yeah,

55:18

there are a few fibers hanging

55:19

on, just barely right there,

55:21

but look at the glenoid side.

55:24

It should go right there to the glenoid,

55:26

should go right here to the glenoid.

55:28

Here's where it is, floating right there.

55:31

There's one end, there's the other end,

55:32

it's a floating IGHL or "AIGL". These

55:38

inferior glenohumeral ligament injuries are

55:41

commonly associated.

55:41

Your next move is to look at

55:44

the MGHL and subscap,

55:46

and look for biceps dislocation.

55:48

The MGHL, hard to see, it's torn;

55:51

but the subscap, easy to see.

55:53

That's way off where it should be,

55:54

it should be attaching here.

55:56

And the biceps is medialized

55:57

and medially dislocated.

55:58

Here's a silly case. Somebody read

56:01

this as a shoulder dislocation.

56:03

It's a middle-aged lady,

56:04

she has decreased range of motion.

56:06

The history is the complete opposite of

56:09

what you would expect in a dislocator.

56:11

Now admittedly,

56:12

some dislocators will guard their arm

56:15

and keep it close to the body,

56:17

and report that they have decreased range of motion,

56:19

but that's really a mistaken identity

56:22

in terms of the history.

56:24

Here is the coronal projection of this

56:27

woman demonstrating some gray signal

56:29

that gets brighter and a little bit glowy

56:32

and on the T2 a little darker because it's made

56:34

of fibroinflammatory infiltrative

56:36

tissue that infiltrates the tendon in

56:40

the entity of adhesive fibroinflammatory

56:43

capsulitis.

56:45

And there's the glow worm that you see

56:47

all the way around the glenoid cup

56:50

which is pear-shaped,

56:52

the so-called corona sign of

56:54

adhesive capsulitis.

56:57

The middle glenohumeral ligament.

56:59

It is

57:00

inverse in size to the IGHL.

57:03

It's shape varies. It can be perforated.

57:06

It can have multiple slips.

57:08

Its course can be horizontal or oblique

57:12

which alters its appearance

57:14

in the axial projection.

57:16

It goes from the lesser tuberosity and

57:18

anterior labrum

57:19

to the scapular neck.

57:21

And I often don't spend a lot of time on it.

57:24

There's an MGHL stubby rupture right there.

57:27

Here's the other end of the MGHL,

57:29

and here's the hole, this thin linear

57:32

condensed anatomic area right

57:35

here is known as the oblique

57:36

fascicles or spiral

57:36

ligament that sits underneath

57:38

the subscapularis.

57:39

But more about that on another day

57:41

when we're

57:42

just focusing labral ligamentous

57:44

anatomy.

57:45

And here's a little bit of

57:47

blood filling out the

57:51

posterior recess of the shoulder.

57:54

The SGHL, it's takeoffs can

57:56

be from the biceps,

57:57

the anterior labrum or it can be common with

58:00

the middle glenohumeral ligament.

58:02

And when it's common with

58:03

the MGHL and the biceps,

58:04

this is known as a Buford Complex.

58:07

And you see a large cord-like structure

58:09

in the upper quadrant over here.

58:11

But that's not the case.

58:13

This is the SGHL

58:15

which should be a nice delicate

58:17

structure. It should come out like this.

58:19

And then it should parallel the course

58:22

of the biceps long head,

58:23

neither which is happening

58:25

very well here.

58:26

So the MGHL likes to follow the

58:28

undercarriage of the subscap.

58:30

The SGHL likes to follow over top up.

58:34

And then peripherally underneath

58:35

the biceps long head,

58:37

neither of those are occurring right here.

58:39

Here's your short stubby, SGHL

58:41

which is ruptured. And by the way,

58:44

the coracohumeral ligament

58:46

which becomes

58:48

the rotator cuff cable, intra articulate

58:49

is torn from its coracoid origin.

58:51

SLAP lesions. I'm going

58:52

to focus on six only.

58:53

The four

58:59

most classic types described by

59:01

Snyder and two common types.

59:04

Let's begin with the four

59:06

types of biceps origins.

59:08

It can start out from the posterior

59:11

aspect of the glenoid,

59:13

mainly posterior, mid and anterior.

59:15

Why is this important?

59:17

Because you're not allowed to have

59:19

a recess or a fissure or a sulcus

59:22

posterior to the biceps take off.

59:24

This is a very important rule.

59:27

So here's an example of a biceps that is

59:29

swollen. So you can see it really well,

59:31

it's not a normal biceps.

59:32

But this is an example

59:34

of an anterior takeoff

59:36

when you're looking in

59:37

the axial projection.

59:38

Now in the coronal projection,

59:39

there are two main subtypes

59:41

of biceps takeoff.

59:43

There's the SLAB type takeoff that takes

59:46

directly off the tip of

59:47

the labrum like this.

59:49

And then there's one that comes over the

59:50

top, it's this dark band highlighted by

59:54

our red arrow and then right underneath

59:57

it is a thin layer

60:00

that is bright.

60:01

And that's known as the sulcus type

60:04

origin of the biceps. Sulcus

60:07

origin, SLAB origin.

60:10

Here are some diagrams demonstrating the

60:13

superior labrum and here is the takeoff of the

60:17

biceps. This one's a little posterior, so

60:20

you can have a little sulcus right here

60:22

which should not go behind the takeoff

60:24

of the biceps. SLAP

60:25

1, fraying; SLAP 2, a fissure; SLAP

60:28

3, a bucket handle tear that

60:30

creates this funny looking round

60:32

Cheerio sign; and SLAP 4, tear of the

60:36

anterior labrum that tracks into the

60:39

biceps long head creating a set of

60:42

railroad tracks more peripherally.

60:44

Let's have a look.

60:46

Here's the coronal projection.

60:47

We are well behind the biceps here.

60:50

We've got a tear.

60:51

We've got a cyst in the front.

60:54

There's a sulcus type takeoff of

60:56

the biceps over the top.

60:58

We have some undersurface fissuring

61:00

right here. Is that real?

61:02

Well hard to say until you keep going.

61:05

It's real, but is it pathologic?

61:07

On the next cut,

61:08

we're behind the biceps

61:10

now, it's brighter and bigger and now

61:12

it's even bigger and now it's even

61:14

bigger and it has a paralabral

61:16

cyst associated with it.

61:18

This is an example of a SLAP 2. Let's

61:21

take a look at SLAP lesions on this

61:23

elegant video provided by Paul Favorito.

61:26

There's the normal labrum.

61:27

This is anterior. There's the biceps.

61:29

There's a normal indentation or

61:30

dippity-do known as the normal sulcus or

61:33

normal indentation. This is high.

61:35

This is low. This is anterior,

61:37

that's posterior.

61:39

Now,

61:39

we're on the undersurface of the labrum

61:41

and look how frayed it is.

61:43

But you can't pick the labrum up.

61:45

That's a one. Now you can pick the labrum

61:48

up. Watch and you'll see some blood

61:50

underneath, there it is.

61:52

And then as you go anterior, everything

61:54

is nice and tight.

61:55

So this would be a SLAP 2. Only at

61:57

the top. If it's in the back, 2 B.

62:00

If it's in the front, 2 A.

62:01

If it's front to back, it's a 2 C.

62:04

Now, I don't have a 3,

62:05

but I do have a 4.

62:06

It's a longitudinal tear that

62:08

goes right into the biceps creating

62:11

a tram track appearance or orientation

62:13

of the biceps.

62:14

Those are your four major

62:17

types of biceps tears,

62:19

less the Type 3 which I'm going

62:21

to show you here in a minute.

62:23

There's a coronal projection

62:24

demonstrating a SLAP 2.

62:26

We're well behind the biceps.

62:28

We have a slightly complex appearance

62:30

to the posterosuperior labrum.

62:32

We don't see it go through and through,

62:34

but we do see a tear.

62:35

Don't call this a ganglion even though

62:37

histologically, it's identical to a ganglion.

62:41

The cyst is the dead giveaway that you

62:43

have a SLAP lesion and the most common

62:46

type to produce this is the SLAP two.

62:49

And you're behind the biceps

62:51

stated once more.

62:53

Here is a SLAP 3.

62:54

A big gap.

62:55

You've got a piece of labrum right here.

62:57

You've got a piece of labrum right here.

63:00

Like bucket handle tear.

63:02

And when you look at the axial projection,

63:04

you have a giant hole in the middle,

63:06

the so-called Cheerio Sign.

63:07

Piece of labrum,

63:09

piece of labrum, hole in the center,

63:12

the Cheerio Sign of a SLAP 3. Now,

63:16

some people will refer to this as the

63:18

fat Oreo cookie sign because there's

63:20

the dark portion of the cookie,

63:22

there's the other dark portion of the cookie,

63:24

and there's the cream of the cookie.

63:27

If you have a sulcus with one

63:28

of these or with the SLAP 2,

63:30

now you can have what's called

63:31

the Double Oreo Cookie Sign.

63:33

Here's your SLAP 4.

63:36

We start out all the way at the top.

63:39

There's our fat, swollen, inflammed

63:42

anterior takeoff of the biceps.

63:44

It's torn and we keep going and

63:47

this signal never stops.

63:48

There is your tram track right there.

63:50

There's one railroad track,

63:52

there's the other railroad track. There is junk in the

63:55

middle and it just keeps going and

63:57

going and going. Here it is,

63:58

there's the biceps again. Again.

64:00

Again.

64:01

Again.

64:02

Again and once more creeping underneath

64:05

and into the intertitium of

64:08

the subscapularis in

64:10

this patient that also has SLAP 4

64:12

with a biceps dislocation.

64:14

The two other common ones are a SLAP

64:17

2 that likes to go around the back,

64:19

the posterior quadrant. We see this in

64:21

weightlifters and military pressers,

64:23

and this is known as a SLAP 8.

64:26

And the other common one that you see in

64:29

degenerated shoulders; it's high, it's superior,

64:33

it's posterior, it's anterior,

64:35

it's posterior again,

64:37

it's still posterior. In the coronal

64:40

projection, it's posterosuperior.

64:41

In the coronal projection,

64:44

it's anterosuperior.

64:46

And somebody that has a SLAB-like

64:48

take-off of the biceps long head, it's a

64:51

SLAP 9 nearly three hundred and sixty

64:53

degrees of SLAP abnormalities.

64:55

And then finally,

64:56

we finish with a flurry

64:58

with the Bennett lesion.

64:59

These are either symptomatic or

65:02

asymptomatic lesions that are a result

65:04

of a contracted posterior

65:08

inferior glenohumeral ligament or capsule.

65:12

So we'll see what we mean

65:13

by this. Over here,

65:14

the capsule gets a little contracted.

65:16

So when the patient abducts the arm, were going to see this in the MRI in a minute,

65:18

they pull off the periosteum,

65:19

they produce an enthesophyte,

65:21

and they bleed into the periosteum and the

65:25

bleeding ossifies. This is not contrast,

65:27

even though we're doing an arthrogram.

65:30

This is ossification.

65:33

But here is the enthesophyte seen on the diagram.

65:34

But here's a real one.

65:37

Here's the axial projection.

65:39

Look how thick the capsule is,

65:41

the so called the IPIGHL,

65:43

the inferoposterior,

65:44

very far posterior.

65:45

IGHL is fat, contracted.

65:47

It's pulled on this part of the

65:50

posterior stabilizing mechanism.

65:53

It is

66:00

produced to periosteal detachment

66:02

with bleeding.

66:03

This is ossified and now we got

66:05

this big ossified lamina fragment. Here

66:07

it is posterior, mid and inferior seen

66:10

in overhead and throwing athletes,

66:12

the Bennett lesion. This one actively inflammed. So we covered three sections, the rotator cuff. I shared with you an understanding of round tendons, length, width, and depth; flat tendons, split tears, delamination tears, and so on. I gave you eponyms: PAINT lessions, STAS lessions, PASTA lesions, CIDs. And now we move on to the section about the labrum. We broke it up into basically a few parts. We talked about the labrum as it relates to dislocation and gave you some rules to deal with some of the labral variations. Then we went on to talk about IGHL and how IGHL injuries commonly occur with subscapularis injuries. We showed you HAGLs, and we showed you a GAGL and an AIGHL. And we talked a little bit about on track and off track and bipolar morphology for labral tears.

67:06

And then spent some time on SLAPs 1

67:08

through 4 and briefly

67:10

SLAPs 8 and 9.

67:12

And then finished very briefly with the

67:14

Bennett lesion unique to throwers,

67:16

it can be symptomatic or asymptomatic

67:18

occurring behind the posterior

67:20

glenoid. With that, I've given you my email if you have any questions and I'll take any question in the Q and A section. Not seeing anything coming in just yet, will give you a few minutes, seconds.

67:36

So Sammy, we often see high signal tear of

67:38

the very superior subscapularis

67:41

tendon on the sagittal images.

67:44

What do you make of it? Well, of course,

67:45

I'd have to see the case.

67:47

But the upper fibers of the

67:50

subscapularis, Sammy,

67:51

are more likely to tear because they

67:53

are almost purely tendinous,

67:54

they're thinner.

67:56

And if you look at the subscapularis

67:58

on the sagittal,

67:59

you'll see it widen as you go down.

68:02

So if you see some signal in

68:03

the upper subscapularis,

68:05

your next move is to look

68:07

at the rotator interval.

68:08

See what's going on with the

68:09

biceps and the SGHL interval?

68:12

Make sure your coracohumeral

68:14

ligament is intact.

68:15

Look for some interstitial extension

68:17

into the subscapularis and also

68:18

take a look at the coracoid. See how close it is to the humerus and perhaps you get abutment syndrome. Thank you for your compliment, Mohammed. very much appreciated. Gempy had a question. Doctor Sinhar. How to differentiate biceps tenosynovitis from fluid tracking into bicipital groove from joint effusion. Well, the best way is clinically. Well, I want to remind you that most patients with adhesive capsulitis will have a contracted capsule and they will force

68:51

fluid into the biceps sheath.

68:53

The fluid then dissects down and their

68:55

chief complaint is, "Doc,

68:57

I can't move my arm,

68:58

but I got pain going down my arm,

69:00

and I get numbness in my fingers," which

69:02

is kind of a weird finding or symptom. So I use the clinical a bit.

69:08

But also,

69:09

when you're looking at biceps

69:11

tenosynovitis,

69:12

you should look inside the fluid.

69:14

Is there synovial hypertrophy?

69:16

Is there synovial metaplasia?

69:18

Do you have vincula or attachment of the

69:22

biceps to the surrounding? Well,

69:23

and are these vincula too thick?

69:26

And lastly,

69:27

do you have some signal inside the

69:30

biceps which would tip you off that you

69:32

have pathologic fluid as opposed

69:34

to fluid that is tracked from the joint? Andrea, thank you for the compliment. Robert, also thank you for the compliment. Alright, with that... We have one more. Do you use neutral position for imaging or external rotation? I used neutral imaging. Some people used routinely the ABER position, the arm abduction and external rotation. I don't do that. I will bring the patient back for that. But because I've been doing this so long, I bring the patient back

70:05

maybe one in five hundred, for the

70:07

purposes of doing that to distract the

70:09

labrum, to look for minor labral tears.

70:11

Most of the time for me,

70:13

that's unnecessary. But I have no objection for you externally rotating.

70:17

But remember it does distort

70:19

the anatomy a little bit. It puts the rotator cuff on a little bit of a stretch, but it also rotates the biceps over and makes it

70:29

harder to look at intraarticular bicep labral anchor abnormalities.

70:32

Does the amount of fluid indicate biceps

70:36

tenosynovitis? And the answer is no;

70:38

the amount of fluid doesn't determine it.

70:40

It's those other things, internal

70:43

synovitis, synovial metaplasia,

70:45

thickened vinculas,

70:47

signal in the biceps. Suchen, thank you. Okay, with that we will call it a day. And thanks to the team in MRI Online for having me

71:06

and thanks to all of you around

71:08

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71:33

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71:37

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71:40

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71:42

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71:44

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71:46

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71:48

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71:48

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