0:00

Let's move on now to our second, uh, tendon,

0:05

and that is gonna be the brachial.

0:09

The brachialis, uh, muscle is the largest

0:11

of the elbow flexors.

0:13

It has two separate heads, a larger superficial head,

0:18

a smaller deep head.

0:20

They both arise from the humerus to superficial head,

0:24

arises higher up on the humerus than in fact does the D

0:28

head, and they extend down distally to attach

0:33

to the ulna in different places.

0:35

The superficial head has a circular

0:40

terminal intramuscular tendon,

0:42

and inserts on a bump known as the ulnar tuberosity.

0:47

Right here. The deep head has what is called a terminal

0:51

pons that attaches to all but the tip of the OID process.

0:57

So this is what it would look like.

0:59

So it's two distal attachments.

1:02

So once again, you can have problems of the tendon of one

1:06

of these heads and not of both.

1:07

But in general, when dealing with the brachi,

1:11

it's more muscle abnormalities that we see, uh,

1:14

rather than tendon abnormalities.

1:17

Just to give you an idea, using these sagittal images

1:20

that if you look closely,

1:22

you can separate out these two heads of the muscle

1:25

and trace them down.

1:27

I've done that here.

1:29

This is the most lateral,

1:30

this is the most medial sagittal image.

1:33

Here's the deep bed. This is the superficial head.

1:36

The deep head is shown with the white arrows

1:40

attaching more approximately on the ulnar,

1:43

the superficial head shown

1:44

by the yellow arrows attaching more distally on the,

1:49

uh, on the ulnar.

1:53

Okay, so using that fab's view,

1:58

I just wanted to give you an idea of why it's good, not just

2:01

for the biceps tendon shown on the right,

2:04

but it's good for the brachialis muscle

2:06

and its tendon shown on the left.

2:09

And you can see normal or abnormal, uh, muscles

2:13

and tendons using this view.

2:15

So if you get a request, which you rarely would,

2:18

that says brachi muscle problem, you might wanna include

2:22

this, um, imaging plane as well.

2:27

Now, I wanna remind you, as I did just a few minutes ago,

2:31

that at the level of the elbow joint, the brachialis

2:36

consists mainly of muscle and not tendon.

2:40

You can find the tendons here, you can find them here,

2:44

but it's mainly muscle.

2:45

Look how thick the muscle is.

2:47

All of this is muscular tissue. Here's the tendonous tissue.

2:52

So in my experience over these years when dealing

2:55

with problems of the brachialis, it's

2:58

Generally been a problem of the brachialis muscle

3:01

and not of the tendon.

3:04

Just to give you some ideas of the muscle abnormalities,

3:08

you can see one of them is myositis o hands

3:11

falling an injury.

3:13

Okay? And here at the time of injury, we didn't see, uh,

3:17

anything other than swelling.

3:18

But here four weeks later, the classic appearance,

3:22

fairly mature, looking now of myositis ance,

3:26

the mr was attained just about at the same time, time

3:29

as we got this plain film.

3:31

And you can see a, uh, a mass,

3:33

a large mass in homogeneous on T one,

3:37

but containing a curva lineal rim of low signal.

3:40

That's very, very typical of, uh, myositis scans

3:45

or heterotopic, um, bone formation, a lot of intermediate

3:50

and high signal centrally.

3:52

And one of the other things I've found to be

3:55

very characteristic is a fusiform pattern

3:59

of muscle edema about the area of ossification.

4:03

Here's what it looked like on gradient echo areas

4:05

of low signal related in to hemosiderin, uh,

4:10

uh, deposition.

4:11

In, in this, uh, case,

4:14

muscle contusions may occur.

4:17

This was a direct blow to the anterior aspect

4:20

of the elbow joint.

4:22

A lot of subcutaneous edema as you can appreciate,

4:26

and you can see the edema within the muscle simulating here.

4:29

I would say also a muscle strain.

4:33

Muscle hemorrhage can relate to hyperextension

4:37

as you would have in the armbar position.

4:41

And this was an example, uh, of actually a subluxation

4:44

and even perhaps a slight dislocation of the elbow joint

4:49

that led to a areas of hemorrhage

4:52

and a hematoma involving portions of the brachialis muscle.

4:56

And as you would expect,

4:58

it's generally the deep muscle belly that suffers more.

5:02

Here's another example

5:04

that occurred following an elbow dislocation.

5:07

You can see the joint effusion, the disruption of the,

5:11

uh, capsule here.

5:13

The mechanism in this case was posterolateral rotary

5:17

instability, and you can see the injury

5:19

and tearing involving the deep head, the muscle

5:24

of the brachialis muscle.

5:26

The superficial head was more normal

5:31

muscle strains

5:32

and delayed onset muscle soreness may also occur

5:35

in the brachialis.

5:37

And actually this is a fairly common site

5:40

for doms about the elbow.

5:43

And then what has been a described in the literature is

5:48

muscle and tendon entrapment

5:51

involving the brachial following radial head

5:54

dislocations. This image

5:56

Taken from the literature sagittal plane showing you in

6:00

fact a dislocation of the radial head

6:03

and mainly the tendon and muscle.

6:06

The deep part was entrapped beneath that dislocated, uh,

6:10

head preventing relocation.

6:13

And in a particular pattern of tearing has been associated

6:17

with this sort of mechanism.

6:20

It's called a buttonhole tear of the brachialis muscle.

6:24

Here's an example. The radial radius is dislocated.

6:28

There's tearing of the capsule,

6:30

and there is a tear involving mainly the deep

6:35

muscle head of the brachialis.