0:01

Let's talk briefly about the deltoid muscle

0:04

and uh, tendon.

0:05

And this becomes important

0:06

because when you're dealing with full thickness

0:11

or with tendon tears, particularly massive ones leading

0:15

to cuff arthropathy or Milwaukee shoulder

0:18

and leading to narrowing of the acromial humeral distance,

0:22

you may in see, uh, see failure of the deltoid muscle

0:26

or deltoid tendon.

0:28

The two most common patterns of failure, one

0:31

where the tendon attaches to the acromion

0:34

or another one at the myo tendon is junction.

0:37

A number of articles have in fact been written on

0:40

this particular topic.

0:41

Here you can see some illustrations of the pattern.

0:44

I'll show you one example here, taken from the literature,

0:48

a near complete tear at the acromial attachment of that

0:53

deltoid tendon,

0:54

and a person with a massive rotator cuff tear

0:58

and narrowing of the acromial humeral distance.

1:02

Let's also just spend a few minutes talking about

1:06

fatty infiltration

1:08

and atrophy of the muscles of the rotator cuff.

1:11

There are two terms, fatty infiltration and fatty atrophy,

1:15

and they are not the same thing,

1:18

although they are closely related.

1:21

Okay? They are closely related

1:24

and in fact often occur together.

1:28

Fatty infiltration may proceed.

1:31

Atrophy, atrophy, rarely proceeds fatty infiltration

1:36

and fatty infiltration of a muscle is generally regarded

1:39

as irreversible.

1:41

Alright? Even with successful tendon repair,

1:46

muscle atrophy may halt after a repair that is successful

1:51

and infrequently.

1:53

There are reports that it, the appearance

1:56

of the atrophy may improve.

1:58

Now, the systems that we use to identify fatty infiltration

2:02

and atrophy are different.

2:05

The guttier

2:07

or modified guttier system is used typically

2:11

for fatty infiltration who say, uh, also has a system

2:15

for this, and it tends to involve the ratio

2:19

of muscle versus fat tissue within each of the components

2:24

of the rotator cuff.

2:26

On your left, you can see exactly the four stages,

2:29

1, 2, 3, and four.

2:31

Okay? And I've listed

2:32

or shown you here the grading

2:34

that would've been used in this example,

2:37

and here were the modification of the gutta system,

2:40

the grading that would be mo used.

2:42

Here, you can see

2:43

that this is fatty infiltration of the muscle.

2:47

Now there's also fatty atrophy,

2:49

but we have different ways of looking at that.

2:52

Here we're dealing with muscle size

2:54

and most of the articles that have talked about methods to

2:59

Identify atrophy have related to the supraspinatus muscle

3:04

with two particular techniques.

3:07

The tangent technique, which is drawn along the top

3:11

of the coracoid process and acromion,

3:14

and a faucet technique, looking at, in fact,

3:18

the area of the fossa and how much muscle occupies it.

3:24

Normally, particularly in young people,

3:26

if you use the tangent technique,

3:28

the muscle will certainly touch that tangent

3:31

and generally goes beyond.

3:33

Okay? I tend to use this, I use it as an eyeball technique.

3:37

Here's an example of both fatty infiltration

3:41

and atrophy involving the uh, supraspinatus uh, muscle.

3:47

Now, there's one really pitfall here

3:50

that I want you to realize.

3:52

If you have a full thickness tear of the rotator cuff

3:56

with muscle retraction shown here,

4:00

that muscle is gonna look very,

4:02

very small in the sagittal plane.

4:05

So I always go back and look in the coronal plane as well.

4:08

There is atrophy here,

4:10

but it looks much worse in the sagittal plane.

4:14

In this fatty infiltration is certainly atrophy

4:16

of the in infraspinatus.

4:18

There are lines that have been tried to identify a fossa

4:22

for the in infraspinatus,

4:24

but they don't seem to work as well.

4:26

I.