0:01

When we do an arthrogram, there are

0:02

several locations we can insert the needle.

0:05

We could insert it at the radiocapitellar joint,

0:08

right over here, or at the posterior aspect

0:11

of the joint, at the ulnar trochlear joint.

0:14

I prefer this joint because it's a much bigger

0:17

space, and it's a lot easier to get into.

0:20

So let me show you, in a diagram,

0:22

exactly how I would come over here.

0:25

Okay, so now we have this

0:27

lateral radiograph of the elbow.

0:30

And let me just orient you so

0:31

we know what we're looking at.

0:33

So we're looking through the

0:35

capitellum and the trochlea at this

0:39

point because it's a lateral view.

0:41

Here is your radial head,

0:43

and here is your olecranon.

0:48

So once you have that, I'm going to erase some

0:50

of this so you can see that a little bit better.

0:52

One other thing I want to point out.

0:54

Let's follow this anterior humeral

0:56

line, and look what it does on one side.

1:01

And we're going to follow the

1:02

posterior aspect of the capitellum.

1:05

Go like this.

1:07

At this point, the bone is awfully thin.

1:11

That's why, just as an aside,

1:15

when a child breaks his or her elbow,

1:17

it typically happens at this location

1:20

because the bone is thinnest there.

1:21

So this causes a supracondylar fracture.

1:24

A supracondylar fracture is the most

1:26

common fracture that happens in children.

1:28

And this is the reason why, because

1:30

the bone is so thin over there.

1:31

Okay?

1:32

That's an important aside

1:33

to sort of keep in mind.

1:34

But our purpose today is to talk

1:35

about the approach of the ultrasound.

1:38

The ultrasound needle posteriorly

1:39

is going to go like this.

1:42

It's going to elevate the fat pad and

1:45

that's how you know you're in the joint.

1:46

This is a very, very big space.

1:48

The patient is typically positioned

1:50

like this with the elbow flexed.

1:52

Now let's go on and see the actual

1:55

ultrasound and see what that looks like.