0:00

Well, let's move on now to the third region

0:03

that we wanna discuss.

0:05

And this is probably the most complex,

0:09

at least I find it the most complex.

0:12

The triceps muscle and tendon.

0:14

The triceps consists of three heads, try,

0:17

obviously three heads,

0:19

the long head which arises from the infra glenoid tubercle

0:24

of the scapula, and then a lateral head

0:27

and a medial head.

0:29

You can see the lateral head here, the medial head here,

0:32

which arise from the posterior aspect of the humerus.

0:38

Now, when you go ahead

0:39

and look at the distal anatomy of the triceps, muscle

0:43

and tendon, you're gonna see why it is complex.

0:47

The long and lateral heads attach as a common central tendon

0:52

that's being shown right here in the area of the asterisk.

0:58

There is a lateral expansion that can be very prominent

1:02

that extends over the ancon incon muscle shown

1:06

by the blue asterisk and the medial head.

1:10

We see it in part here, lies deep to the other two heads

1:14

with both muscular and tendonous attachments.

1:19

Now to give you an idea,

1:20

we'll look at the anatomy starting first

1:23

with the lateral insertional anatomy.

1:26

And there are two structures that we have to look at here.

1:30

We wanna look at the central tendon

1:32

and we wanna look at the lateral triceps expansion.

1:36

The insertion laterally is mainly superficial, so

1:41

that's gonna be the more superficial structures

1:43

that you're gonna see.

1:45

And it is the wider when, uh,

1:48

of the two insertional anatomy patterns that is compared

1:52

to the medial.

1:54

Alright? It consists of that lateral triceps expansion,

1:58

which you can see here

2:00

and here, which is continuous

2:03

with the superficial fascia of the ancon muscle.

2:07

And it also inserts on the lateral aspect of the oma.

2:12

And then the central tendon.

2:14

The central tendon, fairly broad as you can see here,

2:18

has components as you know, of the lateral and long ass.

2:21

But the confusing part

2:23

of the anatomy is it also may have a component derived from

2:28

the medial head.

2:30

So we do have superficial and deep structures,

2:34

but they are connected in some part.

2:37

Let's look at the medial insertional anatomy

2:40

and here we have a deep muscular component

2:44

and you can kind of see that here.

2:47

But we also have a superficial

2:50

medial tendon component which can join the central tendon.

2:55

So part of the medial structures are not all deep,

2:59

Some of them are superficial.

3:02

Now, over the last probably 15 years,

3:04

because I have always found this anatomy confusing,

3:09

I have wr I along with our fellows

3:11

and scholars have written three articles on this anatomy.

3:15

And I'm showing you images from the last of these

3:18

because I always was confused by our results

3:22

in this particular article.

3:24

And you can see the reference to it.

3:27

We used even these playdo models

3:30

to help us figure out the anatomy.

3:32

So as we go from deep to superficial,

3:35

here is the medial head muscle.

3:38

This is the deep layer,

3:39

but here's the tendon which is extending more superficially.

3:44

As we go to the intermediate layer, we can see the long head

3:48

and the lateral head muscles.

3:50

We still can see the short medial head tendon,

3:53

and then the most superficial structures, we see

3:56

that central or common tendon,

3:59

and we see the lateral expansion extending

4:01

to the lateral aspect.

4:04

So there are multiple layers here

4:06

that I think analysis can be difficult.

4:09

So let me show you what these layers look like

4:12

in this particular sagittal Mr image.

4:16

And I'm color coating these for you.

4:18

So this is the triceps muscle that we see up here

4:22

with the green arrow.

4:24

Here we can see with the orange arrow, the deep part,

4:27

which is the muscular attachment of the medial head.

4:31

That's far separate from the common or central tendon.

4:35

But here arising from the medial head is a tendon.

4:39

This is the tendon of the medial head.

4:42

Now we can see here that's shown by the white arrow,

4:46

the blue arrow showing you the central tendon derived mainly

4:51

from the long and lateral uh, heads.

4:53

And then of course the fat bed that's located deep

4:57

to the muscle.

4:59

So this is the layered approach, okay?

5:02

And what I would indicate is the normal footprint,

5:05

particularly on a sagittal MR image,

5:10

through the medial aspect, it is a wide footprint.

5:14

And the reason I'm emphasizing that is

5:17

that I believe if you study the footprint what's missing,

5:21

you'll get a good idea of what structures are torn.

5:25

So let's look at a few examples.

5:28

This is a full thickness, full width tear

5:32

of the triceps, uh, tendon and muscular attachment.

5:36

All right, everything is attached.

5:39

The entire footprint is vacant, so everything is pulled away

5:44

as deep as the muscular attachment of the medial head

5:48

to a superficial as the entire common or central tendon.

5:53

This is an uncommon injury compared to other

5:57

Sites of tendon disruption.

5:59

More common in men

6:01

and women, more common in adults than children,

6:04

more common in athletes than non-athletes,

6:07

particularly weightlifters those particularly

6:10

using steroids.

6:13

It also can be seen in certain diseases, particularly

6:17

hyperparathyroidism, particularly that associated

6:20

with renal osteo dystrophy.

6:23

Diabetes. Complete tears said

6:26

to be more common than partial,

6:28

but I'm not sure that's really the case.

6:31

Distal attachment problems more than myo tendonous problems.

6:36

The usual injury is an eccentric contraction

6:39

such as during a fall.

6:41

Less commonly it could be a direct blow with high energy

6:45

to the elbow region and the finding loss of extension.

6:50

Okay, but if the lateral expansion,

6:53

that part covering the ancon is intact,

6:56

that clinical finding may be missing.

6:59

So this is full thickness for width.

7:01

So let's look at this one.

7:03

This is full thickness, partial width.

7:05

I'm showing you sagittal and axial images.

7:08

This is color coated.

7:10

This is a complete tear of the central tendon

7:14

derived mainly from the long and lateral heads.

7:17

So here with the red arrow is showing you the

7:19

disrupted central tendon.

7:21

And with this red asterisk, this is the uncovered footprint,

7:25

but all of this footprint is still covered.

7:29

The muscular attachment of the medial head

7:33

in this particular case is intact.

7:36

As you can see, the lateral expansion here

7:40

was in intact.

7:43

You can see that, uh, here with the green arrow heads.

7:47

That extending down here is what that,

7:50

what that uh, looked like.

7:51

And the, uh, tenderness attachment

7:55

of the medial head shown

7:56

by this red arrow head is still intact.

8:00

So this is not affecting the muscle

8:04

and tenderness attachment of the medial head.

8:08

Right. Here's another example.

8:11

Full thickness, partial width, a complete tear

8:14

of the central tendon.

8:16

Long and lateral heads very similar

8:18

to the last case here is the retracted central tendon.

8:22

A lot of subcutaneous edema.

8:24

We go ahead and look at the tendon of the medial head.

8:28

I'm showing that with green, uh, arrowhead,

8:31

and you can follow it down here.

8:32

So that's still intact. Look how far posterior it is.

8:36

The muscular attachment shown here with the asterisk,

8:40

the uncovered aquin on footprint is only a small part.

8:45

All of this part of the footprint is intact,

8:48

so certainly not full thickness.

8:51

Full width, this is full thickness,

8:53

partial width. And another example,

8:55

Full thickness partial width.

8:57

This is a complete air of the central tendon

9:00

and the lateral expansion,

9:02

the red arrow is showing you the areas of disruption

9:05

of the tendon and the lateral expansion.

9:08

All right, the tendon of the medial head here is intact.

9:14

The muscular attachment is in intact as well.

9:18

And the uncovered footprint, small,

9:21

it's this area right here.

9:23

So I find the footprint analysis to be particularly helpful.

9:28

And then this final case, 12 months apart, beginning here

9:33

as a, a partial tear of that, uh,

9:37

central tendon progressing to involvement.

9:41

Complete tear of the central tendon here.

9:43

And the medial head tendon shown right here,

9:47

a little bit still attached, but it too is torn.

9:51

So the torn footprint is really this sort of area,

9:54

this footprint here looks intact,

9:57

but the tendon was involved higher up.

10:00

So I, I really think that's the way to analyze the triceps.

10:04

Otherwise it is difficult.

10:06

And in some of these cases when you look,

10:09

you will see bone of hins.

10:11

Now just to finish up the triceps, there is a snapping

10:15

triceps tendon syndrome where there's subluxation

10:18

of the ulnar nerve or the medial head, or both structures,

10:23

and it tends to occur when you flex the elbow.

10:26

So ultrasound is a good way to evaluate it.

10:29

If you examine with Mr the elbow in extension,

10:34

the clue might be,

10:35

although the nerve is in normal position,

10:38

there's subcutaneous edema around the epicondyle.

10:41

So maybe you wouldn't be surprised

10:43

that in the flex position, the nerve

10:46

and the medial head is subluxed.

10:50

And then there may be a low lying medial head,

10:52

as in this case shown by the orange arrows

10:55

where we have subluxation involving the ulnar nerve.

11:01

One of the final point about this would be the aranon versa.

11:05

We certainly get bursitis there.

11:07

Septic bursitis is very common in this bursa Hemorrhagic

11:12

bursitis as well.