0:00

Let's move on to the hip.

0:01

This is a six-year-old boy with right hip pain.

0:07

Here's a radiograph, frontal projection.

0:11

Let's look at what we can see.

0:12

First, I look at the congruity of

0:15

one hip joint versus the other.

0:17

I look at the density, I look at soft tissues,

0:19

and I look to see if there is a joint effusion.

0:21

What immediately grabs my attention is

0:23

the density on one side versus the other.

0:27

You notice this is quite a bit brighter

0:30

than on the contralateral side.

0:32

In addition, there is a linear thin

0:36

lucency just under the chondral surface

0:39

on the right, as you see over here.

0:42

On the left, there's no similar lucency.

0:46

Now let's take a look at some of

0:48

the soft tissues around this joint

0:51

and compare it to this joint.

0:54

I'm going to draw a line for you.

0:56

This is the obturator internus muscle.

1:05

This is the piriformis muscle, okay?

1:09

The distance, if we will, from here to here

1:14

is bigger than the distance from here to here.

1:18

So that tells me there is some elevation or

1:21

displacement of that soft tissue structure.

1:25

Also, the distance between here

1:28

and here is going to be larger than

1:30

the distance between here and here.

1:32

Let's go ahead and measure that.

1:34

That's about 1.1,

1:36

and here it's about 0.73.

1:38

34 00:01:40,525 --> 00:01:43,645 So all that tells me is that there is a joint

1:43

effusion on the right side. The increased

1:45

sclerosis and the lucency tell me that there's

1:48

a little bit of collapse happening and these

1:51

are the classic findings of Legg-Calvé-Perthes

1:56

or a form of avascular necrosis, if you will.

1:59

Some people call it an osteochondrosis,

2:01

some people call it avascular necrosis.

2:04

You know, there's no great answer, but

2:06

it's an area where there's not enough

2:08

perfusion happening to that femoral head.

2:11

In the next vignette, we're going to show you

2:13

what this looks like on MR imaging.