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Today, we're honored to welcome
0:44
for a lecture on shoulder MRI.
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Dr. Pomeranz is the founder of MRI Online,
0:49
authored numerous medical textbooks in MRI
0:52
including The MRI Total Body Atlas.
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Avid conference lecture.
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Chairs fellowship training programs in
0:58
MR and advanced imaging.
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Chair of Naples Florida Community Hospital Network.
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CEO and medical director of ProScan Imaging.
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At the end of the lecture,
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please join Dr. Pomeranz in a Q and A session.
1:10
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1:11
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With that being said,
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we are ready to begin today's lecture.
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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.
2:24
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
2:35
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,
2:54
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,
3:23
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...
3:38
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.
4:19
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,
4:57
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.
5:17
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.
5:48
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.
6:31
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.
6:46
we have a somewhat different nomenclature.
6:48
Of course, if you rupture a round tendon,
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.
8:02
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
8:30
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
9:48
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
11:31
covering the rotator cuff crescent
11:35
And there is your posterior
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
12:06
They may penetrate cartilage or bone.
12:10
this is referred to as a rim rent
12:12
phenomenon or rim rent extension
12:16
Sometimes you can have very tiny tears;
12:19
usually they emanate from the posterior
12:22
rotator interval between the
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;
12:40
they're under surface;
12:41
they're known as supraspinatus tendon
12:43
articular surface tears,
12:46
You can have tears that involve the
12:49
footprint and tear off or
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
13:07
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.
13:23
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
13:35
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
14:08
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,
14:16
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
14:23
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
14:40
That may be a little bit
14:42
of an overstatement.
14:43
And then, here you see on
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.
15:02
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
15:37
just the tendon comes off the footprint. And
15:39
another phenomenon you'll encounter
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
16:19
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?
16:28
Retraction in centimeters or
16:30
based on anatomy. Eponyms.
16:32
The muscle. Is the muscle involved?
16:35
Is there fatty infiltration
16:38
and is it volumetrically compromised?
16:41
Other cysts, other signs of impingement.
16:43
Is there evidence of bursitis
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
17:13
making a zigzag towards
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
17:26
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.
17:37
you have tendon subunits.
17:38
So you can look inside the tendon and
17:41
typically, when you look
17:43
you're going to have this
17:45
where the subunit fibrils are going
17:48
to be parallel to one another.
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.
19:05
the fluid is homogeneous.
19:06
The parallel fibers of the tendon
19:09
and their thickness are preserved. No,
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
19:50
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
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,
20:14
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
21:14
Here's another one right at the
21:17
supraspinatus-infraspinatus
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
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
22:34
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
23:09
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
it was a career-ending thing for him.
23:27
I think, six or seven years in a row.
23:29
One of the best nose tackles
23:33
Here's another example of an eponym.
23:36
This is a footprint avulsion tear.
23:38
The T1, not so informative;
23:42
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
24:14
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,
24:37
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.
25:31
it can easily be confused
25:34
or latissimus dorsi tear.
25:36
The subscapularis is very weird because
25:39
it sends fibers over with the transverse
25:43
It sends fibers to the
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
25:55
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.
26:50
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
27:34
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,
28:28
But when you look at it
28:29
like the surgeon does,
28:30
you have a much different perspective.
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
28:42
Another one is the U-shaped tear,
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.
29:01
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
29:30
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,
30:06
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.
30:32
It's produced auto-acromionectomy
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
31:04
Biomechanical, usually young individuals
31:08
Anatomic impingement,
31:12
Older, older's probably over ninety.
31:13
But let's call older for
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
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,
31:41
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
31:53
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
32:58
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.
33:39
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
34:03
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,
34:23
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
35:11
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
35:50
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
36:09
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.
36:24
the subscapularis is a
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
36:59
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
37:10
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
37:35
We're going to look at the shape and
37:37
conformity and orientation
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.
37:53
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
38:04
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
38:33
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.
39:50
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.
40:02
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,
40:10
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
40:54
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.
41:15
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.
42:43
you get capsular detachment the
42:46
periosteum may elevate a bit.
42:48
And this is known as a posterior
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.
43:06
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
43:16
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.
43:39
The capsule is torn away from the
43:42
labrum, number one. How about the labrum itself?
43:44
It looks like mashed potatoes,
43:47
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.
44:31
we have six abnormalities
44:33
Not to mention the fact that the humeral
44:36
head looks like it's bouncing
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
44:55
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
45:35
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
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
46:31
You have periosteal fragmentation,
46:33
you have labral fragmentation,
46:35
you have capsule detachment,
46:37
and then it starts to look
46:39
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.
48:02
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,
48:30
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
50:03
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
50:20
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.
50:35
there is a little bit of
50:38
and in many individuals in
50:40
this very center of the glenoid,
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
53:02
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,
53:41
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
53:55
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
54:47
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
54:56
You've detached the ligament
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.
56:12
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
56:45
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.
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
57:19
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
ligament that sits underneath
57:39
But more about that on another day
57:42
just focusing labral ligamentous
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
57:57
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.
58:15
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
58:26
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
58:48
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.
58:59
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
59:43
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
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
60:25
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.
60:46
Here's the coronal projection.
60:47
We are well behind the biceps here.
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?
61:08
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,
61:39
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
61:55
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,
62:06
It's a longitudinal tear that
62:08
goes right into the biceps creating
62:11
a tram track appearance or orientation
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
62:55
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.
63:09
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.
63:36
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.
64:02
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.
64:56
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
65:14
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,
65:45
IGHL is fat, contracted.
65:47
It's pulled on this part of the
65:50
posterior stabilizing mechanism.
66:00
produced to periosteal detachment
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
67:12
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,
67:56
And if you look at the subscapularis
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
68:15
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.
69:09
when you're looking at biceps
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?
69:27
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,
70:47
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
the world. Have a great day. Thank you so much for the great talk. We learned a lot. And thanks for all participating in our Noon Conference. I remind you that you can access the recording of today's conference and all of our previous Noon Conferences by creating a free online MRI account. If you like to access our mastery series, courses, case series, and much more educational content with unlimited CME, you can sign up for a free 7-day trial of our MRI Online Premium Membership. You can learn more at mrionline.com with the url at the chatbox. Be sure to join us next week on Thursday, June 16th at 12 pm Eastern time for the lecture with
71:33
Dr. Giuseppe Brancatelli for a lecture on MRI
71:37
of Focal Liver Lesions with Extracellular
71:42
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71:43
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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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