0:00

Okay, when you last saw me, I was riding

0:02

west on the humeral head trail, and we were

0:05

talking about near full thickness tears.

0:09

Tears in pink here that went pretty, pretty

0:12

deep, but maybe they didn't go all the way

0:14

through, or maybe they did and you weren't sure.

0:17

There are a couple tricks that you can use in this scenario.

0:20

One of which is just very carefully

0:22

within sections following to see if you

0:24

can get fluid to drape into the tear.

0:28

But if you got a fair amount of fluid in the subacromial

0:31

space, it's not a slam dunk, but the likelihood that

0:34

this tear penetrates all the way through is pretty high.

0:38

If you're not sure, you can say, pinhole size,

0:41

diminutive, full or near full thickness tear,

0:44

but we are begging, urging you, prompting you to

0:47

differentiate depth from anteroposterior length,

0:51

from retraction, medial, lateral, or width.

0:56

One other caveat I was discussing with one of my colleagues.

1:00

When you have a tear with inflammation and you're really

1:03

not sure just how deep it is, but it's not inconsequential.

1:08

It's causing the patient symptoms.

1:10

It can be very difficult to figure out depth because

1:12

you're, you're evaluating a curved structure in every plane.

1:17

So look at how deep it is sagittally, coronally, and

1:23

even axially, which we haven't talked too much about.

1:26

That's going to be our subject for our next session.

1:32

But if you're unsure, then that's a good

1:34

time to go to what I call the 50% rule.

1:37

The depth is 50%.

1:39

'Cause you can't be too far off,

1:42

as long as it's not full thickness.

1:44

You know, if it's 70%, you're only

1:46

20% off, if it's 30%, you're only 20% off.

1:50

And as I said, it can be very hard to gauge

1:52

unless you have one millimeter cuts with three

1:54

dimensional reconstructions, the exact depth and

1:58

that's kind of like the term moderate.

2:01

Not too bad, not too good, just in

2:04

between and you can't be too far off.

2:09

And you don't have any of these crimping or retraction

2:12

signs to support a high-grade full-thickness tear.

2:18

Now one other caveat as it relates

2:20

to intrasubstance abnormalities.

2:23

When you look inside the cuff, and

2:25

I'm going to blow it up for a minute.

2:28

And I'm going to make the cuff pink.

2:30

Because it's breast awareness month.

2:34

When you look inside the cuff, you are going to

2:36

see, and I will make these little fibrils green.

2:40

So you're going to see the individual fibrils

2:42

in the cuff, and they're going to be parallel.

2:44

These are the subunits of the tendon unit.

2:49

You know, there's epimysium, there's

2:51

perimysium, you may remember that, you may not.

2:53

But that'll be a story for another day.

2:55

So there's subunits within subunits.

2:58

But within the major subunits, you may see a few of

3:01

these fibers wavy, destroyed, ill-defined, crimping.

3:06

In other words, doing this.

3:08

And it's diffusely swollen.

3:10

That is when I start jumping on

3:13

the term tendon fiber failure.

3:18

Which means that the cuff is degenerating,

3:21

it's swollen, it's inflamed, and I am

3:23

missing some of the internal anatomy.

3:26

And there's often irregularity of the humeral head.

3:30

So when things look very messy, like someone stirred

3:32

the pot inside the cuff, you lose the internal anatomy.

3:36

That's when tendon fiber failure becomes very important.

3:43

Now let's, let's go back to the

3:44

sagittal projection for a moment.

3:47

One of your colleagues was asking about the

3:49

very far anterior fibers that go to the lesser

3:53

tuberosity and go over the greater tuberosity.

3:56

And those can be really challenging

3:57

in the coronal projection.

3:58

We'll make C for coronal.

4:00

This is S for sagittal.

4:03

So those tears are often over here.

4:10

one or two-millimeter axial, and a sagittal PD spur.

4:15

They're going to be all the way in the front.

4:17

And they are usually quite unpleasant

4:19

and symptomatic, even if they are small.

4:24

Now when you get further down into the interval, you will

4:29

have swelling, if you have an interval injury, in the

4:32

adjacent soft tissue components of the rotator interval.

4:37

If you get further down, then you start to get into the

4:40

subscapularis, and we're going to talk about subscapularis

4:45

tears and infraspinatus tears in another separate section.

4:51

But, remember that subscapularis tears, even when

4:56

small, can be very annoying because the subscapularis

5:00

attaches to the transverse ligament of the biceps.

5:03

So every time you just slightly turn your arm,

5:06

just to write or to put your pocketbook or purse

5:09

in the backseat, it is incredibly uncomfortable.

5:13

So these small tears will be very

5:16

symptomatic, but they are rarely operated on.

5:19

In fact, almost never.

5:21

But they are the cause of symptoms.

5:23

So you do want to pay attention to the segments

5:26

and to the interstitium of the subscapularis.

5:29

And these far anterior tears may be all

5:31

that's wrong, and you may only spot them

5:34

in the sagittal projection interstitially.

5:38

If you go to the back, remember we

5:40

said nothing much happens here, like U.S.

5:42

Congress.

5:42

Nothing much happens here in the

5:44

posterior interval and in the teres.

5:47

But a lot happens in the infraspinatus.

5:51

We're going to dedicate a whole

5:52

section to the infraspinatus.

5:54

But the infraspinatus comes in

5:56

curved, like the supraspinatus.

5:58

But even more curved.

6:02

It kind of comes in, if you can see my hands,

6:03

it kind of comes in and makes a very tight C.

6:11

kind of skirts underneath the supraspinatus.

6:15

As a result of this curvature, you're often going to see

6:18

something that looks like Bart Simpson's hair on end.

6:23

It's going to look a little bit like this.

6:24

I'm going to have to use a different color.

6:26

I think purple may do it.

6:27

Yep.

6:29

There we go.

6:30

So you're going to see all these little hairs,

6:32

except they're a lot closer together than this.

6:34

I just can't draw them as close together as I need to.

6:38

Maybe I'll make some more hairs.

6:40

Looks a lot like Bart Simpson's hair.

6:43

They're much flatter in the supraspinatus.

6:45

It looks more confluent.

6:47

So if you have inflammation or swelling

6:50

of the infraspinatus, these hairs, which

6:53

are tendon fibril subunits, spread apart.

6:56

A common mistake is to call some of those hairs micro-tears.

7:02

That is usually infraspinatus tendinopathy.

7:06

In an internal impinger.

7:08

But it is extremely common, in internal impingers, to

7:12

see partial thickness, undersurface tears, along the

7:18

deep portion of the infraspinatus, with pitting and

7:21

pseudocysts underneath those, and a swollen infraspinatus

7:26

with the hair spread apart, and a little signal between

7:30

them, and a little bursal signal around the outside.

7:34

And a little bit of posterior superior labral fraying.

7:37

And that defines internal impingement.

7:39

And that's going to be a story for another day.

7:43

So that concludes our session today.

7:46

You know, we have gone from the coronal, to the sagittal,

7:51

to talking about length, and width, and depth, to

7:54

naming some important tears, to giving you some caveats

7:57

to get out of jail when you have a tough situation.

8:01

And in our next sessions, we're going to focus on

8:03

the subscapularis, the infraspinatus, and the axial

8:07

projection and its contribution to rotator cuff

8:12

assessment, and then we're going to dive into some cases.