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Ultrasound of the Rotator Cuff with MRI Correlation, Dr. Jon A. Jacobson (7/28/22)

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Today, we're honored to welcome Dr. Jon Jacobson

0:45

for a lecture on ultrasound of

0:47

the rotator cuff with MRI correlation.

0:49

Dr. Jacobson is a professor of Radiology

0:52

and Section Chief of Muscular Skeletal Imaging

0:54

in the Department of Radiology

0:56

at the University Of Cincinnati.

0:57

His academic achievements include over

0:59

250 peer-reviewed publications

1:01

and many invited national

1:03

and international lectures or workshops.

1:05

At the end of the lecture,

1:07

join Dr. Jacobson in a Q and A session

1:09

where he will address any questions you may

1:11

have on today's topic.

1:12

Please use the Q and A feature to submit your

1:15

question at any time during the lecture.

1:16

With that being said,

1:17

we are ready to begin today's lecture.

1:19

Dr. Jacobson, please take it from here.

1:22

Perfect.

1:23

Okay, let's get going here.

1:24

So, my name is Jon Jacobson.

1:26

I'll be talking about ultrasound of the

1:27

rotator cuff with MRI correlation.

1:31

A few disclosures I'd like to make.

1:33

First of all,

1:34

I want to mention that I put the syllabus of this

1:37

lecture on my website. There's the address.

1:41

I put other educational material related to

1:44

MS ultrasound on there as well,

1:46

but disclosures include consultant

1:48

for Bioclinica, Book Royalties and Elsevier.

1:50

Advisory Board: Phillips,

1:52

Medical Board: POCUSPRO.

1:54

I also have to disclose that

1:56

I no longer eat Skittles.

1:59

So, let's start out with a few general comments

2:01

about the rotator cuff.

2:03

Of course,

2:03

the rotator cuff consists of four different structures.

2:07

At the top, the supraspinatus.

2:08

In the front, the subscapularis;

2:11

posteriorly, the infraspinatus and teres minor.

2:13

Note: the biceps long head tendon coursing superiorly.

2:17

Also want to point out what's colored in light blue.

2:19

And that is the subacromial subdeltoid bursa.

2:21

As the name implies,

2:23

it not only is located under the acromion,

2:25

but wherever you see the deltoid,

2:27

which is removed on this image,

2:29

you'll have that bursa.

2:30

So, it covers many parts of the rotator cuff.

2:36

So, a few basics about ultrasound of

2:39

the musculoskeletal system.

2:40

Tendons are hyperechoic and fibrillar,

2:43

as indicated with the letter T,

2:45

showing the supraspinatus tendon.

2:48

Muscle is relatively hypoechoic,

2:51

although you can see the linear characteristic

2:53

fiber adipose layer is within the muscle tissue.

2:56

Note the echogenic contours of the bone.

2:59

Now, this is a very important point.

3:01

The bone landmarks are essential when performing

3:04

musculoskeletal ultrasound.

3:05

Really, for three reasons.

3:07

One reason is

3:10

that's how you get your orientation.

3:11

You can appreciate the humeral head and

3:14

the shelf of the greater tuberosity,

3:15

simulating what you see on an MRI.

3:18

The second is,

3:19

once you identify the specific bone contours

3:22

that are the footprints of the tendons,

3:24

then you know which tendon you're looking at.

3:26

And the third point, as we age,

3:28

the tendons tend to wear out, or with attrition,

3:31

they occur at those footprints.

3:33

So this is where the money is going to be most

3:35

of the time when looking for pathology.

3:37

So, bone landmarks are really critical.

3:40

Now, there's an artifact that we have to talk about

3:43

when performing musculoskeletal ultrasound,

3:44

and it's called Anisotropy.

3:46

So, what is this?

3:48

Well, this occurs when a structure,

3:51

which is normally hyperechoic,

3:53

is artifactually hypoechoic,

3:54

which can stimulate pathology.

3:57

So, what does this mean and how does it occur?

4:01

Well, if we look here at the segment of tendon,

4:03

these fibers are perpendicular

4:05

to the sound beam.

4:07

So when the sound beam is propagated through

4:09

the soft tissues, it hits these interfaces,

4:12

reflects back up to the transducer,

4:14

and the image is made. Now, the problem is,

4:17

when these interfaces become

4:19

more and more oblique,

4:21

the sound beam propagates through

4:22

the soft tissues.

4:23

But instead of reflecting

4:25

back to the transducer,

4:26

it reflects away from the transducer.

4:28

And the more this is obliqued,

4:31

the more this goes away from the transducer,

4:34

and the tendon will appear more and more hypoechoic.

4:37

Now, it's not just tendons.

4:39

As you know,

4:40

when you guide a needle using ultrasound,

4:42

when the needle becomes oblique and when it

4:44

eventually is 45 degrees to the sound beam,

4:47

it becomes almost invisible.

4:49

So this is anisotropy of any linear structure.

4:53

It only takes about five degrees,

4:55

essentially three to five degrees of angulation

4:57

to make this come and go. So what happens is,

5:00

while we're scanning,

5:00

we're continually moving the transducer.

5:02

When we see a hypoechic area,

5:05

we rock the transducer, hit it at 90 degrees,

5:08

and if it fills in, it's an artifact.

5:11

Okay, the supraspinatus. Let's focus on that.

5:14

Of course,

5:14

the most important tendon of the rotator cuff,

5:17

most commonly torn.

5:19

Here is the long axis view,

5:21

and here is the short axis view.

5:23

Again, hyperechoic and fibrillar.

5:26

Note the convex superior outer surface. Very important.

5:30

And on the short axis, a very uniform thickness.

5:34

When we're over the humeral head,

5:36

here is the hypoechoic hyaline cartilage.

5:38

So this uniform rind of tissue

5:41

is important to see,

5:42

just like we see on an MRI in a

5:44

sagittal oblique image over the humeral head.

5:47

So, to me, this is analogous to a tire on a wheel rim.

5:51

Now, incidentally,

5:51

this is from the Uniroyal tire plant outside of Detroit.

5:57

If you travel west from the Detroit metropolitan airport,

6:00

I'm from Detroit,

6:00

you'll see this next to the freeway.

6:02

Now, these fences are put up,

6:04

these are like 20-foot fences because people

6:06

tried to roll this down the freeway.

6:08

Trust me, it won't work.

6:11

Incidentally, this was initially made for the 1965

6:14

World's Fair in New York City,

6:16

where initially it was a Ferris wheel.

6:18

But let's get back to what's important here.

6:21

Ultrasound.

6:22

Okay, so technical considerations.

6:25

12 to 15 MHz or twelve to 18 MHz

6:28

is the sweet spot for most rotator cuff evaluations.

6:31

Anything over ten will do.

6:33

Anything over 20 sometimes is just

6:35

not enough depth penetration.

6:36

Of those two views of the supraspinatus,

6:39

the long axis view is most important.

6:41

I start with that view.

6:43

There's less pitfalls,

6:44

you recognize the anatomy better,

6:46

and you can diagnose with 90% accuracy with that

6:49

long axis view alone. Although, of course,

6:52

one view is not enough.

6:54

Also, in addition to the bone contours as an important

6:57

landmark, which I mentioned earlier,

6:59

the biceps tendon intra-articular and the rotator interval.

7:02

Another very important landmark.

7:05

More on that in just a moment.

7:07

So, let's continue by talking about the normal

7:09

anatomy and the scanning technique.

7:11

So, here is the long axis view of the supraspinatus.

7:15

When I turn 90 degrees over the humeral head,

7:18

that's when I see the characteristic

7:20

curve of the humeral head,

7:22

the hypoechoic hyaline cartilage,

7:24

and the uniform thickness of the tendon.

7:27

Now, as I move the transducer more distally,

7:30

leaving the articular surface and now venturing

7:33

into the greater tuberosity and its facets,

7:37

we now lose the rounded appearance

7:39

with the hyaline cartilage,

7:40

and it's replaced with this angulated appearance,

7:43

like a shallow roof of a house.

7:46

This will separate the superior

7:48

and middle facets.

7:49

Note that the tendon now is becoming thinner as

7:52

it is attaching to the greater tuberosity.

7:55

Now, recognizing these facets is

7:58

really quite important,

8:00

because when you're looking at a tendon

8:01

in the short axis, you have to decide,

8:03

let's say when there's a tear.

8:05

Is it supraspinatus?

8:06

Is it infraspinatus?

8:07

Is it both?

8:08

How do we make this distinction?

8:10

Well, I rely on the bone landmarks

8:12

for this distinction.

8:14

Looking at the illustration on the left,

8:16

here is the roof of the house that we see,

8:19

the superior and middle facets with this apex.

8:21

Now, the size of the superior facet is somewhat

8:24

variable, but this is what I'm looking for,

8:27

because I know that the supraspinatus

8:29

attaches to the superior facet,

8:30

and some of the fibers

8:32

flop over and attach at the middle facet

8:35

and the infraspinatus overlaps.

8:37

Now, I do recognize that the five layers of the

8:39

rotator cuff, there's variability,

8:41

and fibers do sometimes move

8:44

into different directions,

8:46

but the majority of the tendon will have

8:48

disappearance at imaging as they attach

8:51

to their facets at their footprints.

8:53

Here is the biceps tendon,

8:55

an important landmark to let me know that

8:57

I'm looking at the most superior aspect

8:59

of the supraspinatus.

9:01

Now, here is a video clip showing,

9:05

starting at the humeral head,

9:06

the short-axis view of the supraspinatus.

9:09

Incidentally, the thickened hypoechoic subacromial

9:12

subdeltoid bursa is here.

9:14

The bursal walls are bright.

9:16

This is an abnormally thickened bursa.

9:18

But back to the supraspinatus.

9:19

We have a uniform rind. And as we move distally,

9:23

look what happens as we get to the apex.

9:25

Right there.

9:26

And I'll slow this down and stop right there.

9:29

At that point, we've left the articular surface.

9:32

And now we have the supraspinatus doing this,

9:35

the infraspinatus doing this.

9:38

So, identifying the bone contours

9:40

helps with our orientation.

9:42

And I apply this to MRI as well,

9:43

although the resolution is higher here

9:45

with ultrasound.

9:48

So, differentiating supraspinatus and

9:51

infraspinatus in its short axis,

9:53

I just talked about using the bone landmarks.

9:56

I can do the same thing in long axis.

9:59

And let me explain.

10:01

Well, first of all,

10:02

note the angle between the superior facet and

10:05

the humeral head is more well-defined

10:08

than the angle between the middle facet

10:10

and the humeral head. This is considerably flat.

10:13

So just by scanning a long axis,

10:15

I can tell by these bone contours if I'm

10:18

at the superior facet or the middle facet.

10:21

When I'm over the superior facet,

10:24

we know that this is a long-axis view,

10:26

the supraspinatus.

10:28

As I get to the middle facet more posteriorly,

10:30

I now know, based on the anatomy,

10:33

that the infraspinatus is going to overlap the supraspinatus.

10:38

Taken from the literature,

10:39

if you look at this image,

10:41

images on the bottom left,

10:42

you could see the supraspinatus here.

10:45

And then here's the infraspinatus

10:47

obliquely coming over the top.

10:50

Now, also look with ultrasound what

10:52

we note in this overlap area.

10:55

This is the infraspinatus,

10:57

this flattened tendon,

10:59

but this serrated appearance or

11:02

these linear hypoechoic areas,

11:04

this is the characteristic appearance

11:06

of the infraspinatus.

11:07

Here's the supraspinatus here going underneath.

11:11

So, we're able to identify the infraspinatus and

11:15

supraspinatus based on the bone contours

11:17

and the intrinsic appearance of the infraspinatus.

11:22

Now when I look at the infraspinatus in this view,

11:25

to me, it's analogous to a deflated football.

11:28

Apologies to the Patriots fans,

11:30

but to me it looks like a squished football,

11:33

this being the laces of the football.

11:38

Okay, rotator cuff tears.

11:39

How well does ultrasound perform?

11:42

Well, all the papers show that ultrasound and MRI

11:46

are equal in accuracy.

11:49

Of course, like everything,

11:50

you have to be trained and have experience.

11:52

There is a variability in MRI interpretation,

11:55

just like this variability

11:57

in obtaining images with ultrasound.

12:00

So, there's variability with both.

12:02

You can see with full-thickness tears,

12:04

MR Arthrography, MRI, and ultrasound, over 90%.

12:06

That's what we want.

12:07

MR Arthrography, more specific.

12:11

Now, partial tears, the numbers are lower

12:14

because the tears are smaller,

12:15

where MRI and ultrasound are,

12:19

again, fairly equal but lower.

12:21

But because many of these partial tears

12:22

are articular-sided that will fill with contrast,

12:27

MR Arthrography is more specific

12:29

and is also more sensitive.

12:34

Okay, so what do rotator cuff tears

12:35

look like on ultrasound?

12:38

Well, the normal tendon is hyperechoic.

12:40

Therefore, a defect will be hypoechoic or anechoic,

12:44

meaning the defect will fill with fluid,

12:47

with hemorrhage, with granulation tissue,

12:49

with synovium.

12:50

Now, I'm going to be talking about four indirect

12:53

signs of rotator cuff tears.

12:55

I want to mention two upfront because

12:57

they're very important,

12:58

and I'm going to emphasize them

12:59

throughout this talk.

13:01

The first, cortical irregularity,

13:03

specifically at the supraspinatus footprint.

13:05

In fact, if you see this on a radiograph,

13:09

three out of four patients will have a tear.

13:11

Actually, in my experience,

13:13

it's probably closer to 85% and 90%

13:15

will have a tear,

13:16

and you do not see that cortical irregularity with tendinosis.

13:20

Now, the other indirect sign is volume

13:22

loss or thinning of the tendon,

13:24

where the superior convexity is flattened.

13:27

More on that in just a moment.

13:28

And at the end of the spectrum,

13:30

when the tendon is torn and retracted under

13:32

the acromion, there's nonvisualization.

13:36

Okay, so if we look at rotator cuff tears,

13:39

the supraspinatus is, of course, the most common.

13:42

With larger tears,

13:43

they can extend anteriorly

13:45

into the subscapularis.

13:46

They can extend inferiorly to the infraspinatus,

13:49

uncommonly isolated tears of

13:51

those other two tendons.

13:53

When patients are under the age of 35 or 40,

13:56

rotator cuff tears are not very common.

13:58

Now, the problem is they tend to be smaller,

14:01

partial, articular, and anterior.

14:03

As you know, our numbers go down in accuracy.

14:07

What's important,

14:08

papers have shown up to 30% to 40% of patients,

14:12

if they're under the age of 40

14:14

and have a rotator cuff tear,

14:17

will also have labral pathology.

14:18

As you know, ultrasound is not very good

14:21

at looking at the labrum.

14:22

So, one algorithm would be based

14:24

on the patient's age.

14:25

The younger the patient,

14:27

meaning under 40 or 35,

14:28

perhaps an MRI would be

14:30

the best imaging test to go first.

14:33

And maybe an MR Arthrogram,

14:34

if you have a high suspicion of a labral tear.

14:37

On the contrary, as you age over 40 and 50,

14:41

that's when we see degenerative tears.

14:44

The information about the labrum

14:45

may be less important.

14:47

They tend to occur at the posterior

14:48

aspect of the supraspinatus.

14:50

And again, when large,

14:52

can extend anterior or posterior.

14:54

All right. So when I look at the rotator cuff

14:58

by MRI and ultrasound,

15:00

I try to put the abnormality into one of these

15:04

categories: partial tear, full-thickness tear,

15:07

and tendinosis.

15:08

So, let's talk about that in more detail.

15:12

First, another few points about anatomy.

15:14

The anatomy is so key.

15:16

So there are actually three surfaces

15:18

to the rotator cuff tendons.

15:20

You have the bursal surface and the articular

15:23

surface, and the greater tuberosity surface.

15:25

It's a shelf of bone,

15:27

a broad shelf that actually represents another surface.

15:31

Similar to what we see on the MRI.

15:35

Now, when people talk about the supraspinatus on

15:38

ultrasound, and even to less extent,

15:40

on MRI, the analogy is it looks like a bird's beak.

15:44

And I really don't like that analogy because all the

15:47

birds I've seen, their beaks come to a point,

15:50

except maybe a toucan.

15:52

But I won't get into that.

15:53

The point is,

15:54

it doesn't really come to a point.

15:56

If you can see here by these images,

15:58

the bursal fibers attach out here,

16:00

the articular fibers here,

16:02

and the fibers in between.

16:04

In between.In between.

16:04

So, it's actually a broad attachment.

16:06

They call that the footprint.

16:08

Any ligament or tendon attachment to bone,

16:11

that surface area is called the footprint.

16:14

So rather than a bird's beak,

16:16

I think this is more analogous to a rainbow.

16:20

So that's just one way to think about it.

16:24

Okay.

16:24

So, when you see a defect of a

16:27

tendon by ultrasound or MRI,

16:28

here's an example where it's touching

16:31

the articular surface,

16:33

not going to the bursal surface, therefore,

16:36

a partial-thickness articular-sided tear.

16:38

Note the cortical irregularity that occurs

16:41

with these attrition tears as we age,

16:43

where the fibers are tearing off the bone,

16:46

creating the bone irregularity.

16:47

The Sharpey's fibers.

16:48

Now, there are other terms for this,

16:50

which makes it somewhat confusing.

16:52

A Rim-rent tear is an older term, a PASTA lesion.

16:56

First of all, I don't like acronyms.

17:00

We forget what they stand for.

17:01

In fact, if you put pasta into PubMed,

17:05

there are now three different

17:06

definitions of PASTA.

17:09

Partial articular sided tendon bulge is one of

17:12

the three. So I just call it what it is.

17:14

It's a partial-thickness articular-sided tear.

17:17

Yeah, I don't like acronyms.

17:19

Maybe I should make an acronym for that, IDLA.

17:23

There you go.

17:24

Okay, how about a bursal-sided partial tear?

17:27

Well, there's the defect touching the bursal surface,

17:31

not touching the articular surface,

17:33

therefore not a full-thickness tear.

17:36

Now, note it is touching the bone.

17:38

So, it's incorrect to say that a bursal defect

17:41

touching bone is a full-thickness tear.

17:43

That's incorrect.

17:44

It has to touch the articular surface.

17:47

In fact, most bursal-sided tears do occur at their bony

17:51

attachment as we age.

17:52

That's where it happens.

17:54

And there's the cortical irregularity.

17:57

And because the tendon is really not a bird's beak,

18:00

but rather more like a rainbow.

18:02

You could have defects within

18:03

the tendon such as this,

18:05

where it wouldn't be seen at

18:07

arthroscopy or B, note, the cortical irregularity.

18:11

Know these illustrations,

18:12

I'm putting the biceps for orientation.

18:14

Very important.

18:15

Then finally, the full-thickness tear,

18:17

going from bursal to articular surface.

18:19

Note the significant remodeling and the greater

18:21

tuberosity that occurs with these larger,

18:25

more chronic tears.

18:28

So, also remember that the supraspinatus

18:31

is not a cable-like structure.

18:33

It's more like a flattened structure,

18:36

like a piece of lasagna or something like that.

18:38

So when you have a full-thickness tear,

18:41

which is defined as a defect going from

18:43

the articular to bursal surface,

18:45

it could be focal like this,

18:48

or it could be full-width.

18:50

So, you can either use those terms

18:52

or simply measure the width.

18:53

But just be aware that when you

18:55

have a full-thickness tear,

18:56

we have to consider the width

18:58

or the extent of that tear.

19:02

All right,

19:02

let's move on to supraspinatus pathology.

19:06

Those were a lot of general comments,

19:07

but the anatomy is really quite important.

19:10

So, let's get to it and show some examples.

19:14

Here we see, on your left,

19:15

a well-defined hypoechoic area

19:18

that persisted no matter how we move the transducer,

19:21

touching the articular surface,

19:23

the rounded surface of the bone,

19:25

there's the hypoechoic hyaline cartilage

19:27

not going to the bursal surface,

19:29

therefore a partial-thickness articular-sided tear.

19:32

I would have measured it as maybe 3 mm in length.

19:34

We would measure its width in the other plane.

19:37

I would say it's about 40% deep

19:40

or maybe up to 50% depth.

19:42

Now, we use the term long and short axis with

19:45

ultrasound because we're not looking at the body

19:48

from an external perspective

19:50

as coronal and sagittal.

19:51

As you can see here with the hand on the hip,

19:54

this transducer is pointing at the patient's ear.

19:56

We're not in a coronal or sagittal plane.

19:58

We're following the joint around.

20:00

So we're always talking about the axis relative

20:02

to the structure of interest.

20:04

Now, note here on the right,

20:05

a fluid-sensitive MR image.

20:08

It's essentially an inverted image from the ultrasound.

20:13

The tendon here normally is dark.

20:15

The tendon is normally bright on ultrasound.

20:17

The tear is bright. They usually are on MR.

20:21

And here it's dark. The bone cortex is dark.

20:23

Here the bone is bright.

20:25

So it's really the same thing.

20:27

So if you can make your ultrasound

20:29

look like an MR,

20:31

you're home free because it's the same anatomy,

20:34

it's the same pathology.

20:36

You just have to work on getting the bone

20:39

landmarks and seeing the tendon perfectly in

20:41

long axis or short axis without an artifact.

20:44

But that's what we do with MR anyways.

20:47

Now, there's one significant pitfall with these

20:49

partial articular-sided tears,

20:51

and it relates to focal anisotropy.

20:54

Let me explain what this is

20:56

and how we can avoid this.

20:57

So when we think about anisotropy, just like

21:00

magic angle phenomenon, and with MRI,

21:02

it tends to be all or nothing,

21:04

where an entire segment of tendon

21:06

will have the artifact.

21:08

But the problem here is you could have focal

21:11

anisotropy that looks exactly like a partial

21:13

articular-sided tear.

21:14

First of all, why do we have this appearance?

21:17

Well, this is explained by the anatomy.

21:20

Proximally, while the tendon fibers are more uniform,

21:22

look what happens at its footprint.

21:24

Most of the tendon is going straight,

21:27

but right here,

21:28

these articular side fibers are making

21:30

an abrupt turn.

21:31

Therefore, this area right here is prone to focal

21:35

anisotropy, while the outer part is still normal.

21:38

So how do we avoid this? Well, first of all,

21:41

when you look here and say, well, first,

21:43

I don't see tremendous bone irregularity,

21:45

which would make me think

21:46

maybe it's an artifact,

21:48

but maybe it is tendinosis and that's why we

21:50

don't have the bone irregularity.

21:52

Well, what we simply do is we recognize

21:54

that this is a pitfall location,

21:56

and then we heel toe and move the transducer.

21:59

Look what happens with this hypoechoic

22:01

area as they start the Sydney clip.

22:03

I'm barely moving the transducer and

22:06

it completely fills in.

22:07

Now, there's a little calcification here,

22:09

I'll give you that. But the, quote,

22:11

defect goes from now tear to normal.

22:14

So, just be aware.

22:16

I've seen this error being made with even some

22:19

of the most experienced sonographers and

22:22

radiologists because it's really tricky.

22:24

So this is one thing I've learned over the years

22:27

about this focal anisotropy simulating

22:29

a partial articular tear.

22:32

Here are some other examples

22:33

with MR correlation.

22:35

Focal, hypoechoic, touching the hyaline cartilage,

22:38

not touching the bursa.

22:40

Here it is bright on T2 MR image.

22:43

Here's the width of it.

22:44

Note, this is called the cartilage interface sign.

22:47

We normally see a thin white

22:49

line over the cartilage,

22:50

but when fluid is laying on top of it,

22:53

such as filling in a tear,

22:56

that linear echo will become brighter.

23:01

Okay, let's move on to partial-thickness

23:03

bursal sided tears. Now, the pitfall with these,

23:06

because they're often related to impingement,

23:09

is that the bursa is going to be thickened and

23:12

the defect will then often be filled in with

23:15

synovium and other tissue, which can,

23:16

at first glance, simulate tendon.

23:18

If we look here on the MR first,

23:21

the outer border of the supraspinatus should

23:23

come over like this. But instead, it dives in.

23:26

We have this triangular defect filled with

23:29

debris from the bursa, and here it is as well.

23:33

So, it's important not to call this tendon.

23:35

It doesn't look like tendon.

23:36

The tendon is actually doing this.

23:38

And I would say this is about 75% uncovered,

23:42

75% depth with maybe about 4 mm in length.

23:46

But it's not touching the hyaline cartilage,

23:48

therefore not a full-thickness tear.

23:51

Here's a companion case.

23:53

There's the hypoechoic area.

23:55

Note the cortical irregularity,

23:57

one of the important indirect signs,

23:59

and there's the volume loss,

24:01

the other important indirect sign.

24:04

So I find that this volume loss,

24:06

or loss of normal superior convexity,

24:08

is often brought out best in its short-axis view,

24:12

as we can see here.

24:14

There's the cortical irregularity as well.

24:16

So this, to me,

24:17

is analogous to a flattened tire appearance.

24:20

Whereas I mentioned over the humeral head,

24:22

you should have a nice rounded appearance

24:25

of a tire on a wheel rim.

24:28

Another companion case with MR correlation.

24:30

Note the cortical irregularity.

24:32

There's the defect, there's the volume loss.

24:35

Here's the volume loss.

24:37

Now, I'm not pushing excessively to

24:39

make this volume loss occur.

24:41

It just happens with the normal transducer pressure.

24:44

Of course, cortical irregularity.

24:46

Very difficult to see on MR.

24:48

You do appreciate the thinning of the tendon

24:50

though, just like we see on the ultrasound.

24:54

Okay, here is a full-thickness tear.

24:56

It's going from the articular surface to

24:59

the bursal surface.

25:00

The first point,

25:01

it's filled with fluid. It's anechoic.

25:04

When you have fluid within a tear,

25:06

which occurs more commonly with an acute tear,

25:10

our accuracy goes really high.

25:12

This is 100% accuracy.

25:13

Well, 99.9%.

25:14

Nothing's 100%.

25:16

The point is, you can see the end

25:18

of the tendon very easily.

25:19

Here's that cartilage interface sign where the

25:21

normal bright line is brighter than normal

25:24

because fluid is laying on it.

25:26

So that's telling me,

25:27

indeed, it's touching the articular surface.

25:30

So we have this full-thickness tear and we have to decide,

25:33

is it focal or is it full-width?

25:36

Okay, I'm going to go to the short axis

25:38

to help with that.

25:39

Here is the cartilage interface sign,

25:41

humeral head. There's the width of the tear.

25:44

So, I'm going to do is I'll move the transducer

25:45

more distally and I'll look at this shape of the

25:49

roof of a house showing the superior and middle facets.

25:53

So now, if I look at this image,

25:56

if I were to color in the area where I think the

25:59

tear is on the illustration, it would be here.

26:02

It's the posterior part of the supraspinatus.

26:05

The anterior part is still there with tendinosis.

26:08

Here's the infraspinatus that's still intact.

26:11

And indeed,

26:12

the most common site of a degenerative

26:14

supraspinatus tear is posteriorly right over this apex.

26:20

Okay.

26:20

Here's another case, but this is a larger tear.

26:23

Look at the degree of retraction here.

26:27

There's hyaline cartilage interface,

26:28

there's corticoregularity,

26:30

and this is really thinned

26:31

because there's no tendon there.

26:33

It's just fluid.

26:34

In short axis,

26:36

we can appreciate the thickness of the

26:38

infraspinatus and rather than that coming all

26:40

the way around with a uniform thickness,

26:42

it just thins out to really the collapsed bursa and fluid.

26:46

Here's the biceps tendon.

26:47

Again, a very important landmark to note that we're

26:50

looking at the most anterior

26:52

aspect of the supraspinatus.

26:53

So how about if we were to determine,

26:56

is this full width?

26:57

Well, this one is.

26:59

I would say this whole area,

27:01

the superior facet has no tendon.

27:03

The middle facet here,

27:05

where we expect to see supraspinatus, is missing.

27:08

There's the biceps.

27:09

So this is a full-width, full-thickness tear.

27:12

Or you could measure because they're usually

27:14

about 2.2 to 2.3 or larger centimeters in width

27:18

when the entire supraspinatus is torn.

27:22

Here, just showing that case with MR correlation,

27:25

I think you can appreciate the retraction of the tendon.

27:29

You see the normal infraspinatus

27:31

and no tendon anteriorly.

27:35

And then this whole idea of looking at facets,

27:37

I use that when I interpret MR as well.

27:40

Here's the superior facet,

27:41

there's the middle facet.

27:42

We see no tendon here,

27:44

and where it should flop over, it's missing.

27:46

And here's the infraspinatus coming in

27:49

from the more posterior aspect.

27:53

Now the pitfall with these full-width,

27:55

full-thickness retracted tears is when it's a chronic tear,

28:00

because a rule of thumb is

28:02

with ultrasound and MR, for that matter,

28:05

with more chronic pathology, tendon problems,

28:07

ligament problems, when the fluid goes away,

28:10

is resorbed, we just can't define things as well.

28:14

So unlike that acute foldicus tear where we saw

28:17

fluid outlining the end of the tendon, here,

28:20

the fluid has been resorbed and we just see this

28:23

gradual tapering of the tendon and

28:24

it's hard to see the end of it.

28:26

It's actually...

28:28

It's right here.

28:28

But you probably measure it from here because

28:30

you can't put a suture through that.

28:32

The other difficulty is,

28:33

with all the remodeling,

28:35

you have to really use your imagination to say

28:37

this is where the shelf of the tuberosity

28:39

should be at its footprint.

28:41

So, I'd measure it from here to there.

28:44

But that's the pitfall

28:45

with any chronic tendon problem by imaging,

28:48

is when the fluid is reabsorbed.

28:50

Here's an intrasubstance tear.

28:53

There's the defect.

28:55

There's the cortical irregularity,

28:57

not touching the hyaline cartilage, but close,

29:01

not touching the collapsed hypoechoic

29:04

subacromial subdeltoid bursa.

29:06

Note here the lack of the cartilage interface sign,

29:09

although it's pretty darn close,

29:11

but I would say it's not touching

29:14

the articular surface.

29:16

All right, let's move on from tendon tear to tendinosis.

29:20

First nomenclature.

29:21

We do not use the term tendonitis because the

29:26

inflammatory cells are gone by day five or

29:29

seven in any tendon in the body.

29:31

Now, I do recognize there is a background of inflammatory

29:34

mediators with every pathology in the body.

29:37

For example, if you look at,

29:40

let's say, thyroid cancer.

29:42

There are inflammatory mediators just because

29:44

they are present with thyroid cancer,

29:46

I'm not going to call it thyroiditis.

29:48

The point here is we're calling it tendinosis.

29:51

The other thing is that we know that putting

29:54

steroids into the tendon is bad.

29:56

Putting steroids over tendinosis will give you

29:59

short-term pain relief because it stabilizes

30:02

the nerve endings,

30:03

but has nothing to do with inflammation.

30:05

So we're trying to establish why

30:07

are we injecting steroids?

30:09

Where is it helping?

30:10

Calling the disease or the pathology what it is

30:13

is the first step.

30:14

Another side point,

30:16

the term tendinopathy.

30:17

That is an ambiguous term.

30:19

Many of the clinicians I talk to around the country,

30:21

when you say tendinopathy,

30:23

that means pathology of tendon,

30:25

including tendinosis, calcific tendonitis,

30:29

tendon tear, and even tenosynovitis,

30:32

and other tendons.

30:33

Where many radiologists, especially in Europe,

30:36

they use the term tendinopathy,

30:38

synonymous with tendinosis.

30:40

I'm not here to tell you what

30:41

word you should use,

30:42

but just realize there may be ambiguity

30:44

in some of the terminology.

30:46

This is why I'm sticking with the word tendinosis.

30:49

It consists of mucoid degeneration, primarily,

30:51

chondroid metaplasia.

30:53

Here are the obligatory histology slides

30:56

with arrows pointing at things.

30:59

So, tendinosis will appear hypoechoic.

31:02

How do we distinguish this from a tendon tear?

31:05

Well, the rule of thumb is the more anechoic,

31:08

well-defined, and homogeneous,

31:10

the more likely it's a tendon tear.

31:13

Where if it's more ill-defined and heterogeneous,

31:16

it is tendinosis.

31:18

By the way, heterogeneous is not a word

31:21

in the medical dictionaries used with pathology,

31:27

not to get on this topic.

31:28

Heterogeneous is a term that's used

31:31

in biology but not in the human body.

31:34

Just like homogeneous has to do with milk.

31:36

Homogeneous...

31:38

Whatever.

31:38

I'm going off on a tangent.

31:40

Let me get back to the two

31:42

most important indirect signs:

31:44

volume loss and bone irregularity.

31:47

This is how I make the distinction between

31:50

tendon tear and tendinosis.

31:52

Tendinosis,

31:52

the tendon will tend to be enlarged,

31:54

especially if it's moderate or severe,

31:56

but the bone is smooth at its footprint.

31:59

Where a tear,

32:00

we will look for these two important indirect signs

32:03

of cortical irregularity and thinning.

32:05

Here's a case of tendinosis.

32:08

The tendon is diffusely hypoechoic.

32:11

However, it's not a discrete abnormality.

32:14

The bone is completely smooth.

32:17

There's no loss of the normal convexity.

32:19

And as you know, with MRI,

32:21

gray signal equal the muscle

32:23

is characteristic for tendinosis.

32:26

All right,

32:27

as we leave rotator cuff pathology,

32:30

we need to always include information

32:32

about fatty infiltration.

32:33

And then when the muscle is small,

32:36

the muscle bulk is small. Fatty atrophy.

32:39

We know that there's one finding that predicts

32:43

if a repaired cuff tear will actually do well by MRI,

32:48

that would be the infraspinatus.

32:51

That this one paper said was the only variable

32:53

to predict cuff healing. So fortunately,

32:55

we can see that really easily with ultrasound.

32:58

I look at the supraspinatus too.

33:00

But the infraspinatus is the most important

33:02

structure to talk about fatty infiltration

33:05

and muscle atrophy.

33:06

We know that the larger and the more

33:09

chronic rotator cuff tears,

33:10

especially the ones that are more anterior involving

33:14

the rotator cable,

33:16

are more likely to retract

33:18

and create this problem.

33:21

Ultrasound is comparable to MRI is what it says.

33:24

To be honest, mild atrophy,

33:26

mild fat infiltration, MR will do better.

33:29

But when you get to grade 3 or 4 goutallier on MR or CT,

33:33

ultrasound will be fine.

33:35

You can see it.

33:38

So what I do is I look, in short axis, of the infraspinatus

33:43

compared to the teres minor.

33:44

The key bone landmark is this ridge of bone in

33:47

the scapula to identify the muscle-tendon

33:50

junctions of these two,

33:51

where the infraspinatus is normally

33:53

twice as large as the teres minor.

33:55

Here you can see it's almost the same size,

33:58

telling me there's atrophy.

33:59

Also note that the muscle, rather than hypoechoic

34:03

is echogenic and the tendon-muscle

34:05

differentiation is gone.

34:06

Now, as an aside,

34:08

I never compare to the deltoid,

34:10

I never compare to the trapezius.

34:12

In patients with a large BMI,

34:14

especially those who are diabetic,

34:16

we often see fatty infiltration.

34:18

But the teres minor is normal in 97% of rotator cuffs.

34:23

So, that is my intrinsic standard.

34:25

In the long axis,

34:26

you'll see that all these interfaces will

34:29

attenuate the sound beam, making it difficult.

34:32

Now, let me just make a side point about the physics

34:35

of what's going on here, because I think

34:36

this is important to understand.

34:38

So, what does pure fat look like on ultrasound?

34:41

Well, it's nearly anechoic.

34:43

This is fat here with these fibrous layers in between.

34:47

Muscle is hypoechoic.

34:49

So you might ask why,

34:50

when you mix hypoechoic fat in hypoechoic

34:53

muscle, why does it become echogenic?

34:56

Well, it has to do with the physics of how

34:58

an ultrasound image is formed.

35:00

Remember an ultrasound image,

35:02

we're essentially looking at interfaces or reflections.

35:06

What produces the brightness of the reflection

35:08

is the impedance difference

35:10

across that interface.

35:12

So even though muscle alone is hypoechoic

35:15

and fat alone is hypoechoic,

35:17

when you mix them together like this,

35:20

their impedance differences create reflections

35:22

at every single interface.

35:24

This is why it's brighter.

35:26

It's the same reason why edema or inflammation

35:29

of a muscle becomes echogenic as well.

35:32

So back to fatty infiltration.

35:34

There you go. That's the physics part.

35:37

Extended field of view can help.

35:39

Here we can see the normal teres minor.

35:41

Here we can see the infraspinatus and supraspinatus,

35:45

echogenic, loss of tendon, muscle differentiation.

35:47

Look at the trapezius and deltoid.

35:50

That's why don't compare to those.

35:52

Look at the teres minor.

35:55

Here's the contralateral side.

35:57

Note that this is about twice as large of the teres minor,

36:00

meaning the infraspinatus.

36:02

The tendon-muscle differentiation,

36:04

we can appreciate both the supraspinatus

36:06

and infraspinatus.

36:08

Okay, secondary signs of rotator cuff tears.

36:10

I've already talked about them.

36:12

I'm going to briefly mention them as we continue forward

36:16

on this journey through the rotator cuff.

36:19

So these are the four.

36:21

The first two, cortical irregularity, volume loss.

36:23

The most important.

36:25

I'll mention these other two, as well.

36:28

So we know how important this finding is.

36:31

In fact, when I'm looking at a radiograph

36:33

with an external rotation view,

36:36

if you see cortical irregularity,

36:38

three out of four dentists,

36:39

I mean three out of four patients are going to

36:42

have a rotator cuff tear.

36:42

In my experience, it's closer to 90%.

36:46

So this is a very important finding to say,

36:49

maybe you need an ultrasound or an

36:51

MRI of the cuff. If it is smooth,

36:53

you do not have a cuff tear most of the time.

36:57

96% of the time, there's no cuff tear.

37:00

Remember, tendinosis does not produce

37:02

cortical irregularity.

37:04

So you shouldn't say this is correlating with

37:06

rotator cuff pathology.

37:07

That's incorrect.

37:08

It's specific to a cuff tear.

37:11

Now, again, I'm talking about the supraspinatus

37:13

attachment on the greater tuberosity.

37:18

Now incidentally,

37:18

when we look at the subscapularis,

37:21

I see cortical irregularity,

37:23

probably about 50% of the time it's routinely seen.

37:27

Some of these are vascular channels.

37:30

The point is, when I see it,

37:32

I'm going to slow down and look for a tear.

37:34

But nearly every time, there's no tear.

37:37

So just recognize that I'm specifically talking

37:40

about the supraspinatus footprint.

37:42

Similarly, if you look under the infraspinatus,

37:44

as you know, the bare area,

37:46

will commonly be irregular,

37:48

as a normal variant from vascular channels,

37:52

although we know it can be excessive

37:53

with internal impingement.

37:55

The point is,

37:56

the specificity of the cortical irregularity

38:00

causing related to a cuff tear,

38:02

it's more specific for the supraspinatus.

38:06

So that's number one,

38:07

cortical irregularity, supraspinatus attachment.

38:10

When you're scanning,

38:11

if you see cortical irregularity at that supraspinatus footprint,

38:14

slow down because if there's a tear,

38:16

it's going to be there.

38:18

The second one, volume loss.

38:20

We've talked about this.

38:21

Well, I've talked about it, you've heard about it.

38:23

Here is a full-thickness tear where the loss

38:26

of the superior convexity is now concave.

38:29

Here's a bursal-sided tear.

38:31

Again, concavity.

38:32

This is a thickened bursa over the top,

38:34

filling the gap,

38:36

going beyond the greater tuberosity.

38:38

So we don't see this with tendinosis.

38:41

And you uncommonly see with articular side tears

38:43

because they're just too deep.

38:45

Very important indirect sign.

38:46

Those are the two that are most important.

38:48

Here is a companion case,

38:49

a short-axis view showing the biceps and

38:52

the supraspinatus in short axis.

38:54

And when I start the cine clip,

38:57

what you'll see here is

39:00

the supraspinatus should be located here,

39:02

but rather, it ends there.

39:04

So the first point here is seeing the biceps

39:07

tendon tells me there indeed is an anterior tear.

39:11

If I were just back here,

39:12

I would have missed it.

39:14

So, I want to make sure I'm looking anterior now.

39:16

Note the volume loss and the fluid,

39:18

there's the cartilage interface.

39:19

So we got all the findings of a cuff tear.

39:22

Incidentally, the fluid is tracking over the biceps.

39:27

So, the rotator interval pulley system is torn.

39:33

And this is coursing over the top.

39:35

This person will be prone, say,

39:36

to having biceps tendon,

39:39

subluxation and dynamic imaging,

39:41

and prone to having a subscapularis tear.

39:44

So the coracohumeral ligament is torn.

39:47

This is probably part of the superior

39:49

glenohumeral ligament, which is there.

39:50

But the point is,

39:51

the biceps pulley is involved with this anterior cuff tear.

39:56

Okay. The third or fourth indirect signs,

39:58

the least specific.

39:59

If you have fluid in the joint,

40:02

usually seen first around the biceps tendon

40:04

long head, as you know,

40:05

that connects to the glenohumeral joint in everyone.

40:08

And in the bursa,

40:09

there's a 95% positive predictive value.

40:12

Now, I think that number is actually

40:13

quite a little high,

40:14

and probably someone needs to redo this research

40:17

because a small amount of fluid

40:19

in both is really nonspecific.

40:21

But what I found was when you have significant

40:23

fluid in both, you should think about it.

40:25

But to be honest,

40:26

it's the other indirect signs and the primary

40:28

sign of a cuff tear that we rely on.

40:31

But I'm just including this for completeness' sake.

40:34

And then finally,

40:34

the cartilage interface sign.

40:37

Here, we can see this bright interface,

40:39

brighter than normal,

40:40

because fluid is laying on top of it.

40:42

Now, I want to point out this is an uncommon

40:44

appearance of a rotator cuff tear.

40:46

Most cuff tears occur at the footprints after

40:49

the age of 40.

40:50

If you're younger,

40:51

you have acute injury,

40:52

you could have a more proximal tear like this.

40:55

Of course,

40:56

if you have the less common proximal tear,

40:58

you won't have the cortical irregularity that

41:00

you'd see with an older attrition tear.

41:02

So this would explain why we don't see the

41:04

cortical irregularity.

41:07

And it's limited because it can be subjective.

41:09

But nonetheless,

41:09

I think it's the third most important,

41:12

but not the top two, for sure, indirect signs.

41:16

Okay, infraspinatus and subscapularis.

41:19

It's really the same primary features that we've

41:22

talked about with the supraspinatus,

41:24

hypoechoic and thickened tendinosis,

41:27

often combined with supraspinatus.

41:30

Hypoechoic to a more well-defined

41:32

defect with cortical irregularity.

41:34

Here's the tear of the infraspinatus,

41:37

usually not isolated,

41:38

usually an extension posteriorly of

41:41

a supraspinatus massive tear.

41:44

Subscapularis,

41:45

partial-thickness articular-sided tear.

41:48

Here we can see it involving the articular surface,

41:51

but not going to the bursal surface.

41:53

There is a bursal surface here,

41:55

as I showed in that second image.

41:57

That subacromial deltoid bursa covers

42:00

a fair amount of the subscapularis.

42:03

Wherever you see deltoid,

42:05

the bursa will be present.

42:09

Probably the most common full-thickness tear

42:11

I see in the subscapularis is a focal tear.

42:14

So what do I mean by that?

42:15

First of all, here is the contralateral side.

42:19

We see the multiple tendon bundles of the subscapularis.

42:23

Cephalad is here, inferior there.

42:25

In this case,

42:26

all these tendon bundles are missing

42:28

except for this one.

42:29

This is a full-thickness tear because it goes

42:32

from the articular to bursal surface.

42:33

But is a focal tear,

42:35

meaning it's not the entire width of the tendon.

42:38

So, I've seen some people call this a partial tear.

42:40

I kind of get that.

42:42

But if you're using the criteria

42:43

for the supraspinatus,

42:44

we should be consistent with the remaining

42:47

rotator cuff tears,

42:48

because there is a bursal surface,

42:50

there is an articular surface.

42:52

Therefore this is a full-thickness tear,

42:55

although more focal.

42:58

Here is a full-width full-thickness tear

43:01

with complete retraction.

43:02

Here's the tendon that's pulled off.

43:04

Here's contralateral side.

43:06

If we look in the short axis,

43:08

compared to the contralateral side,

43:10

it's completely missing.

43:12

Here's the subacromial subdeltoid

43:13

bursa coming over the top.

43:15

Again, it covers much of that tendon.

43:19

Okay, finally,

43:20

we're going to wrap up this talk using the topic

43:24

of calcific tendonitis.

43:27

So first of all,

43:28

when I see calcification in a tendon,

43:30

and I'll focus on the rotator cuff,

43:33

I try to put it into two categories:

43:34

a degenerative linear calcification,

43:37

usually in a background of tendinosis,

43:39

or a more globular collection,

43:42

which is when I use the term calcific tendinosis

43:45

or tendonitis.

43:47

Remember that in the early phases,

43:49

it's not inflamed,

43:50

in the resorptive phase, it is.

43:52

If you want to split hairs,

43:53

you could use either term

43:55

depending on the phase,

43:56

or I think most people just use

43:58

them as synonymous terms.

44:00

But these are...

44:01

it's a globular collection.

44:03

And what is interesting is

44:04

the theory of why this occurs.

44:06

It's tendon metaplasia.

44:07

It's not even degenerative.

44:09

It's interesting.

44:10

It's more common in women over the age of 40,

44:13

and people with calcific tendinosis,

44:15

typically do not have a cuff tear.

44:17

So, why do women over 40 get this more so than men?

44:21

And why don't they have cuff tears?

44:23

We haven't figured it out.

44:24

But it's a totally different process than the

44:27

degenerative calcification,

44:28

and it's treated differently.

44:30

Meaning that I will lavage and aspirate

44:32

when it's more globular

44:34

in this calcific tendonitis category.

44:37

Some people use the term barbotage,

44:40

although people find that term as ambiguous,

44:42

so they don't know what it means.

44:43

I just call it what I'm doing,

44:45

I lavage it and I aspirate it.

44:47

So first of all,

44:48

here's one of those linear degenerative calcifications.

44:51

Now, this looks like a fibrotic tendon that's coming over.

44:54

And you can barely see it on the radiograph.

44:57

It is indeed mineralized,

44:58

but it's not globular.

45:00

I'm not going to put my needle in here because

45:02

I'm not going to get anything out of it.

45:03

I guess you could fenestrate it or do a tenotomy

45:06

like any area of tendinosis.

45:07

But usually,

45:08

I don't intervene with these,

45:09

and that's why I downplay them

45:13

because I don't want to go the next step and treat this.

45:18

This is the calcific tendinosis,

45:21

tendonitis category.

45:22

Look how globular this is.

45:24

In the formative phase,

45:26

it typically shows shadowing;

45:28

in the resorptive phase,

45:29

which is when it's truly inflamed

45:32

and typically symptomatic,

45:33

there's less shadowing,

45:34

and these can be quite symptomatic.

45:36

I've had a number of patients who come through

45:38

the emergency room with rule out septic shoulder.

45:41

And what's important is,

45:42

if you in your practice,

45:44

routinely put a needle into a shoulder joint

45:47

under fluoroscopy for septic joint,

45:50

you should always assess the soft tissues before

45:53

blindly putting your needle to the joint,

45:54

meaning you need an MRI or an ultrasound to make

45:57

sure there's no septic bursitis

45:59

or calcific tendonitis before just putting

46:01

the needle into the joint.

46:06

So here are two other examples of calcific tendinosis,

46:09

technically tendonitis.

46:11

This is starting to become less echogenic

46:13

in the center as it becomes more resorbed.

46:16

Remember, the natural course of these

46:18

is they eventually will break out into the bursa

46:20

and be resorbed.

46:22

And if you wait long enough, ten years,

46:24

they will typically become asymptomatic.

46:27

Most people don't want to wait that long.

46:29

Uncommonly, it can erode into the bone.

46:31

These are extremely painful.

46:33

And pitfall with this is the edema in the bone.

46:36

On MRI, it can look like a metastasis;

46:38

it can almost look like a fracture.

46:39

I've seen it hot on a bone scan

46:41

and called it a metastasis.

46:43

These are really painful and can simulate a lot

46:47

of different pathologies at other imaging.

46:49

But here we see the calcium going into the bone.

46:53

So here's the one with MRI correlation

46:55

in the subscapularis.

46:56

Of course, calcification is low signal,

46:59

it can blend in with the tendon.

47:00

But usually, it's thickened.

47:01

It doesn't look like tendon.

47:03

But just be aware that correlating with

47:05

radiographs can make the interpretation

47:07

of the MRI so much easier.

47:09

And here we can see it in the formative phase.

47:13

So just a couple more slides,

47:15

and then we'll end this lecture and I'll answer questions.

47:20

So, regarding treatment.

47:21

So, lavage and aspiration is now considered

47:24

standard of care

47:25

because it is simple and it works.

47:28

Now, there are different ways of

47:29

doing this procedure.

47:30

The most common way and the way I perform this

47:33

is a one-puncture technique,

47:35

where I take a 20-gauge needle,

47:36

I advance it into the calcification

47:40

and then because it's only one puncture,

47:43

I now have a pressure head

47:44

so that when I lavage,

47:46

meaning I barely put in a half of mL

47:48

of saline or lidocaine.

47:49

I release the plunger and it comes back on itself,

47:52

or you can aspirate a little bit.

47:55

The point here is I'm not fenestrating.

47:57

I'm not breaking it up because I don't

47:58

want to just break it up

47:59

and I don't want to damage the tendon.

48:01

I want to get the calcium out of the body.

48:03

Now, if this isn't working, I might resort to just,

48:05

okay, I'm just going to poke the heck out of it.

48:08

But my goal is a one-puncture technique,

48:10

lavage and aspirate.

48:12

And then I bring the needle out.

48:14

I'll inject steroids into the bursa.

48:17

Very important, because if you don't do that,

48:20

I've seen patients come back with

48:22

"Septic Bursitis"

48:23

because what calcium that's left,

48:25

trickles into the bursa, inducing inflammation.

48:28

So the steroids in the bursa

48:30

on the way out is very important.

48:33

So, this variety where there's less shadowing

48:36

is easier than the kind with shadowing,

48:39

and you have this positive reinforcement,

48:41

and we can see exactly what's going on.

48:43

So, here's the last case I'm showing.

48:45

This was the largest calcification that I've ever seen.

48:48

Unfortunately, it was in my wife's shoulder,

48:50

and it didn't go away,

48:53

so I had to do something about it.

48:54

So we put a needle in it, the royal we.

48:57

So when I put the needle in,

48:59

it was kind of hard to get it in there.

49:01

I had to put a little bit of elbow

49:04

force to get it in there.

49:05

And I don't have the positive reinforcement of

49:09

what's happening when I'm pulsing the lidocaine.

49:12

But we got a punch of calcium out of this.

49:16

So after that procedure,

49:18

I backed the needle out and I injected bursa,

49:22

and we were done.

49:23

Again, one puncture technique.

49:24

I didn't break up the calcification.

49:27

So after the procedure,

49:30

the patient's pain started to increase around

49:33

week two, which has been described.

49:36

I didn't have to ask for feedback.

49:38

I received feedback daily about the pain increase.

49:41

Then on week three,

49:42

the pain went to zero.

49:43

And I said,

49:43

"I got to take a look and see what happened."

49:45

This is what it looked like in week three.

49:47

It turned to dust.

49:48

Again, I did not break this up.

49:50

All I did is a one puncture technique.

49:53

So to say that the ones that shadow don't work,

49:56

incorrect.

49:57

To say that you have to break it up,

49:59

incorrect.

50:00

Although some papers say breaking it up works, too.

50:03

Again,

50:03

my goal is to get the calcium

50:05

out of the body and not just

50:08

spread it all around the shoulder.

50:10

Okay, take-home points.

50:11

The first thing,

50:13

which I didn't talk about,

50:15

is that when you perform ultrasound of the shoulder,

50:19

you have to follow a comprehensive protocol.

50:22

Unlike other areas, other extremities,

50:24

where you can focus a little bit more into a

50:27

regional assessment based on symptoms

50:28

or history, you really need a protocol.

50:30

On my website,

50:31

I have a link to a video

50:33

on how to do a shoulder ultrasound.

50:35

You can refer to that.

50:36

Most cuff tears: supraspinatus, rotator interval.

50:40

Again, landmark showing that we've seen

50:42

anterior far enough.

50:43

And the greater tuberosity,

50:44

the bone anatomy is so important for

50:46

understanding where we are in space.

50:49

The most important indirect sign of supraspinatus tear

50:52

is that cortical irregularity,

50:54

and the volume loss would be number two.

50:57

And then finally, calcific tendinitis, lavage and aspiration.

51:00

It really does work well.

51:03

And don't forget to inject steroids into the

51:06

bursa at the end.

51:07

So, that's my website.

51:08

I put a bunch of stuff on there.

51:09

I got some free videos and whatever.

51:12

Also, I want to mention that what I'm doing

51:14

in the next kind of chapter in my career is

51:16

I'm focusing more on outreach.

51:19

I am working with Imaging the World, a nonprofit.

51:22

Dr. De Stigter, the chair of the University of Vermont,

51:27

has been working in Uganda for 10 years with OB ultrasound.

51:29

I'm establishing shoulder ultrasound programs

51:31

there in two different cities,

51:33

and you can refer...

51:34

you can take a look at this organization.

51:36

It's excellent.

51:37

The next thing I'm going to try to do

51:38

in the next year is do outreach in Alaska

51:41

and American Native reservations.

51:43

Again, I want to focus in areas

51:45

where MRI access is limited,

51:48

where the shoulder ultrasound can really work.

51:52

So, I want to thank everyone for your attention.

51:55

And I can now answer questions.

51:58

Okay,

51:58

so if you want to access that Q and A button,

52:01

you've got about seven or eight questions right now.

52:04

Okay.

52:05

The first question here says,

52:08

"In Ultrasound-Guided Shoulders,

52:11

should we write partial-thickness tears in our reports?"

52:14

I'm not quite sure what that means,

52:17

but let me interpret it.

52:19

I know before I do any procedure

52:21

I'm going to do...

52:22

I want to make sure there's some diagnostic information.

52:24

A prior MRI.

52:25

A prior ultrasound.

52:26

So you need to assess what's going on,

52:30

and indeed, I will talk about that.

52:33

Now, maybe the question relates to

52:36

would you do a lavage or would you inject steroids

52:39

with partial tears?

52:40

I have that discussion with my referring docs.

52:43

Most of them will say,

52:45

"Yes, please do the procedure."

52:46

But you really need to discuss that with

52:51

your referring docs.

52:52

Next question.

52:53

Any experience with elastography to take partial tears?

52:56

So Elastography,

52:56

I see, in shear wave,

52:58

is in the experimental phase.

53:00

The deeper the structures,

53:02

the more difficult it is.

53:03

There's so much subjectivity to

53:06

the technique and interpretation.

53:08

I think we're not there yet.

53:10

I know there's been most work on the

53:11

achilles because it's linear.

53:13

There's no isotropy and superficial,

53:15

but I say it is...

53:18

it's too soon to really go further with that.

53:22

The next question.

53:25

Post-traumatic dystrophic calcification

53:27

versus calcific tendinitis in the rotator cuff.

53:30

So it's interesting,

53:32

if we look at tendons around the body after an injury,

53:36

the one tendon that stands out where we see

53:38

ossification is the achilles.

53:40

It's funny,

53:41

I do not see ossification of a tendon

53:44

anywhere else in the body after trauma.

53:45

I mean, you can, like, partial avulsions,

53:49

like, ischial tuberosity where it becomes irregular,

53:51

but I'm talking about mineralization within the tendon.

53:54

It's really only the achilles.

53:57

Now, on the flip side,

53:57

I've only seen one case of true calcific tendonitis,

54:01

meaning hydroxyapatite deposition on the achilles.

54:04

Why do we see hydroxyapatite in every tendon

54:06

and rarely the achilles?

54:09

And why do we see ossification primarily in

54:12

the achilles and rarely anywhere else?

54:14

I don't have no idea.

54:15

So I guess, to answer the question,

54:18

by imaging,

54:19

it would be hard because they're both echogenic

54:21

and they're both shadowing.

54:22

I would rely on the radiograph.

54:24

That's what I would do,

54:25

because a radiograph would show mineralization,

54:28

a cortex, and trabeculae of true ossification,

54:31

where the amorphous appearance of

54:34

hydroxyapatite calcification,

54:36

they will look differently.

54:37

That's how I would do that.

54:40

Okay, next question.

54:41

How to evaluate labrum and glenohumeral ligaments?

54:44

So, with regard to labrum,

54:46

the posterior labrum we can see fairly well.

54:49

We published a study where we were pretty good

54:51

in saying normal versus abnormal.

54:54

But in the big picture,

54:56

the accuracy isn't there.

54:57

The superior labrum,

54:58

I can see about 40% of the time,

55:01

but I don't feel confident enough to really go there

55:04

with my reporting.

55:06

I started looking at the anterior

55:07

inferior labrum for a while,

55:09

and I found it didn't add value.

55:11

I will look for an obvious paralabral cyst,

55:14

but I still glance at these areas of labrum.

55:17

But I really...

55:18

if it's questionable, I get an MRI or suggest one.

55:21

So, I really don't spend a lot

55:22

of time on the labrum.

55:23

I'm really looking at the rotator cuff primarily.

55:27

Next question.

55:28

How to differentiate a rim rent tear versus

55:29

a degenerative linear calcification.

55:32

So a rim rent tear,

55:34

which is a far distal articular-sided tear,

55:36

will appear hypoechoic or anechoic, well-defined

55:39

touching the articular surface.

55:41

The cortex of the great tuberosity,

55:43

the footprint, will often be irregular.

55:45

So that'll be different from a linear calcification,

55:49

in that the calcification would be thin and echogenic.

55:52

Typically, not shadowing

55:54

because it's so thin.

55:55

So I guess what the question was getting at is,

55:59

if you have shadowing from calcification,

56:01

could that simulate a tear?

56:03

Well, I would say that, first of all,

56:05

calcific tendonitis, usually don't have a tear.

56:08

And the linear degenerate calcification,

56:10

you typically don't have shadowing.

56:11

So, I don't think that's really a problem.

56:14

Okay, next question.

56:16

Lavage.

56:17

Do you inject only 1 ml of lidocaine,

56:19

or do you repeat it?

56:20

So, what I do is I load up three syringes,

56:23

and I probably put maybe 1 to 2 ml of

56:26

saline or lidocaine into each.

56:28

Now, I don't inject 2 ml.

56:31

Rarely I do. The thing is,

56:33

with the one puncture technique,

56:34

there's not a lot of space for that injection.

56:36

So I basically just pulse, maybe a 0.2.

56:40

I don't even look, just as much that can go in,

56:43

and I release the plunger,

56:44

and it tends to come back on its own.

56:46

I have to admit, I've had more diffuse calcifications

56:48

where I could put an ml or one and a half in,

56:51

and then I'll try to aspirate it out.

56:54

So, I just put maybe 2 to 3 ml into each syringe.

56:57

And when the syringe starts to get cloudy,

56:59

I just switch to the next one.

57:01

So, that's just arbitrary of how I do it.

57:05

Next question.

57:06

Should calcific tendonitis patients take

57:08

any oral medication post lavage?

57:11

Typically when a patient leaves,

57:14

they have...

57:15

they're asymptomatic because there's lidocaine

57:17

in the tendon, a little bit in the bursa,

57:19

and there's steroids.

57:20

So typically, they don't need to take anything.

57:22

But what I do is I'll say,

57:24

take what you normally

57:25

would take over the counter for pain.

57:28

So, that's usually how I approach that.

57:31

Next question.

57:35

What are the findings that you look for

57:36

for shoulder ultrasound?

57:40

So I guess,

57:42

let me just talk about arthritis in the shoulder

57:44

for a minute.

57:45

So osteoarthritis,

57:46

the hallmark is the inferior osteophyte

57:49

on the radiograph.

57:50

We typically don't see much on ultrasound

57:52

other than a joint effusion,

57:54

sometimes some heterogeneous

57:56

synovial hypertrophy.

57:58

Now, if you have an inflammatory arthritis,

58:00

like rheumatoid arthritis

58:01

or even ankylosing spondylitis,

58:03

then you'll see more tissue distension

58:05

of the posterior recess

58:06

and the biceps tendon sheath,

58:08

often with hyperemia and with erosions,

58:13

so they appear differently.

58:15

So hopefully, that will answer that question.

58:19

The next question is...

58:21

Rule number one,

58:22

always read the question to yourself

58:23

before saying it out loud.

58:25

Otherwise, it can get embarrassing.

58:26

Let me see here.

58:28

How do you describe posterior superior rotator

58:31

cuff tears in the coronal plane?

58:33

So, let me think about that. The coronal plane.

58:36

So a coronal plane on MR would be a long-axis

58:41

view of the supraspinatus.

58:43

And if I'm describing a posterior superior tear,

58:47

I would again go short-axis to the tendon and

58:50

see where it is on the greater tuberosity and describe,

58:53

is it the posterior part of the supraspinatus or

58:56

is it indeed the infraspinatus? Or is it both?

58:59

So I guess the answer would be,

59:00

I would try to precisely put it into one or both tendons,

59:04

using the bone landmarks as my

59:07

way to sort that out.

59:10

Next question.

59:11

If subscapular tendon is thickened and

59:14

hypoechoic, can it be called a tear?

59:16

So, I would use the same primary and indirect

59:20

findings of a cuff tear in a supraspinatus.

59:22

I would look for a well-defined

59:24

hypoechoic or anechoic abnormality called a tear.

59:27

I would look for thinning of the tendon.

59:30

I would look for cortical irregularity.

59:31

So, I would apply all the criteria that

59:34

I talked about for supraspinatus.

59:35

So just thickened and hypoechoic,

59:37

I'll call that tendinosis .

59:40

Looks like I got one more question here.

59:43

How do surgically repair tears

59:45

look on ultrasound?

59:47

How would...

59:48

How about a lecture on this?

59:49

Sure, I could do that another time.

59:51

But the idea is when they reattach the tendon

59:55

to the trough that they make,

59:57

or with suture anchors,

59:59

the tendon can be thick,

60:01

it can be thin, it can be hypoechoic,

60:03

it can be anything.

60:05

What I'm really looking for is the tendon

60:07

attached to that suture anchor or to the trough.

60:12

It can be thin, so I can't use that.

60:15

The cortex is irregular.

60:16

I can't use that finding.

60:17

And so I really simply report,

60:19

is there a definitive defect to call re-tear?

60:23

If I'm not sure, I'll get a follow-up,

60:26

because some of these smaller tears will heal.

60:28

And even when they reattach,

60:30

it's not always a uniform attachment.

60:32

So, I hesitate to call it re-tear unless I'm really sure.

60:38

Of course, if you get a follow-up,

60:41

the real tears will tend to propagate and get worse.

60:45

And then one last point is that

60:47

if you see suture material that's not in the tendon,

60:50

that's bad,

60:50

it means the tendon pulled out of the suture

60:53

or the suture pulled out of the tendon.

60:59

And let's see. It's 1:02.

61:01

Let me see if there's anything else here

61:03

I can get to in the next 1 minute.

61:07

How do you get calcium with one puncture technique

61:10

rather than fragmentation?

61:11

Well, the inside of that calcific tendonitis

61:14

is like toothpaste.

61:15

It's the outer shell that's more ossified.

61:19

Or not really ossified, it's calcified.

61:21

But the point is,

61:22

when you put the needle into the center through

61:25

that outer shell, it's more like toothpaste.

61:28

And by lavaging it, it loosens it up,

61:30

and you can pull out the calcium.

61:32

So, that is really what I'm aiming to do

61:36

to take the calcium out.

61:40

All right.

61:43

I think that's all I can see.

61:46

Dynamic. Is that...

61:47

Dynamic.

61:48

One more.

61:49

Does dynamic help with cuff tear?

61:50

I find it does not. And the reason is,

61:54

we do stretch the tendon out in the modified

61:56

crafts maneuver where the hand is on the hip.

61:58

But unlike a tendon, that's like a cable,

62:00

like in the wrist, the hand, and the ankle,

62:02

where you can bring out the retraction because

62:05

the tendon is so broadly attached

62:07

and the overlapping fibers,

62:08

I cannot bring out really tears, dynamically,

62:12

more than what I see statically.

62:13

Of course,

62:14

bicep subluxation dislocation is a dynamic maneuver.

62:18

All right.

62:18

Well, thank you again for your attention

62:20

and the opportunity to speak to you today.

62:23

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62:25

I learned a lot.

62:25

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62:27

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63:12

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Report

Faculty

Jon A. Jacobson, MD, MD, FACR

Professor of Radiology, Section Chief of Musculoskeletal Imaging

University of Cincinnati

Tags

Shoulder

Musculoskeletal (MSK)

MSK

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