0:00

So we're back to our discussion of the

0:03

six components of the rotator cuff.

0:05

And we've got a case here where it just lights out.

0:09

Everything's here.

0:10

Dogs and cats living together,

0:11

ten days of darkness, the plague, mass hysteria,

0:14

and all the cuff structures are involved.

0:17

So we start up high in the axial projection

0:20

and we see a giant curvilinear crescent or U.

0:24

That's this right here.

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In fact,

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it's so beautiful,

0:28

I've got to put some colors on it.

0:31

It's too tempting.

0:33

There it is, right there.

0:35

All of those structures should be over here,

0:38

peripherally on the humeral head.

0:40

This is a giant hole right here.

0:43

Of course, everybody forgets to look at

0:46

the poor axial projection.

0:49

Let's work our way down.

0:52

And as we come down, we see a large hole,

0:55

which means the capsule is ruptured.

0:57

You got lots of fluid leaking out anteriorly,

0:59

so the capsule is torn.

1:01

And there is our poor coracohumeral ligament,

1:04

the retracted edge of it,

1:06

which should have gone all the way over and inserted

1:09

on the humeral head, the coracohumeral ligament.

1:12

So the coracohumeral ligament

1:14

and the capsule are torn.

1:16

Here's our biceps anchor coming in to the labrum.

1:21

It forms very often when you can see it with

1:24

high-quality imaging such as this, a V or a Y.

1:28

We said the biceps can come in anteriorly

1:30

and plug right into the tip here,

1:33

or it can parallel the labrum for a bit, anteriorly,

1:36

or it can come off in the mid,

1:38

or it can come off in the back.

1:40

There's quite a bit of variability in the

1:42

takeoff of the biceps labral anchor.

1:44

So let's keep working our way down, and as we do,

1:47

we run into the rest of the biceps.

1:49

Let's follow it with our scroll.

1:50

Here it is.

1:51

There it is.

1:52

There it is.

1:53

And it never comes back to the

1:55

proper location ever again.

1:58

Keep watching it.

1:59

It always stays perched on the lesser tuberosity.

2:02

And that's because the fibers that

2:04

normally keep it in over here,

2:05

namely the subscapularis fibers

2:08

and the transverse humoral ligament,

2:10

which inserts here,

2:12

which is formed mostly by the already known torn,

2:15

coracohumeral ligament, is gone.

2:17

Allowing the biceps to displace into the arms,

2:22

the loving arms of the subscapularis.

2:25

It can go all the way through into the joint,

2:27

it can stay in the subscapularis,

2:29

sometimes it can ride over the top of the subscapularis,

2:33

three types of biceps subluxation,

2:35

but we're talking about the biceps because it is the

2:38

third component now of the rotator cuff that we've

2:41

seen that is damaged, torn, or ruptured.

2:44

Let's keep going, shall we? We're moving on down.

2:47

Let's pay attention to the subscapularis.

2:49

Moving on down, moving on up.

2:51

We are missing the subscapularis fibers right here,

2:54

at least the deep ones.

2:56

The superficial ones are intact,

2:58

but the deeper ones

3:00

are torn.

3:01

And with those fibers runs the middle glenohumeral

3:05

ligament, which attaches right there. It's intact.

3:08

So the deep fibers of the subscapularis are injured.

3:12

The superficial fibers are intact.

3:15

So at least we've got some of the cuff still present.

3:18

But what about that large gaping hole that we saw

3:22

in the axial projection? What's that about?

3:26

Let's get some coronals going here.

3:29

Probably the most favored nation status projection

3:32

for the rotator cuff, the one that everyone likes.

3:38

And let's see if we can scroll them together.

3:41

We've got, on the far right,

3:43

a water-weighted image, a PD/SPIR.

3:46

In the center, a T2.

3:47

And on the left, a T1.

3:49

Let's start scrolling.

3:50

We've got our biceps,

3:52

which is right here under my little magnifying glass.

3:55

Well, it's still there,

3:57

but we already know it's malpositioned.

3:59

We already know it's subluxed,

4:01

so it's not doing its job of helping

4:03

to keep the humeral head depressed.

4:04

But what about the supraspinatus?

4:06

Well, that explains our massive hole, right?

4:09

There's our hole.

4:10

And where is the supraspinatus?

4:12

Oh, it's migrated all the way over here.

4:14

Here's a piece of it.

4:16

Here's another floppy piece of it, just kind of lying

4:20

in that space, attaching to absolutely nothing.

4:24

If we try and follow this back a little bit,

4:26

it's bunched up over here at the myotendinous junction.

4:30

So the subscapularis is just a bloody mess

4:33

with massive retraction, accounting in part for that hole.

4:37

Now, let's go back to the infraspinatus.

4:40

There's the tip of the infraspinatus.

4:43

I use the word tip somewhat cavalierly

4:47

because it's not really a tip.

4:48

It's a broad-based, fan-shaped structure.

4:51

But this is the free edge of it and it should

4:53

be all the way over here.

4:54

So that's toast.

4:56

And then we go to the teres.

4:59

And we still have a teres.

5:01

So the good news is we have a teres,

5:03

we have much of the subscapularis intact,

5:06

the deep fibers injured,

5:07

but everything else is gone.

5:09

We've gone through our checklist.

5:11

Supraspinatus, blown, retracted, complete.

5:15

Infraspinatus, blown,

5:17

retracted and complete from front to back.

5:20

Subscapularis deep fibers, injured.

5:22

Biceps, subluxed.

5:25

Caracohumoral ligament, ruptured.

5:27

Capsule, torn.