0:00

Here's another patient with hip pain.

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This is a 10-year-old girl with left hip pain.

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I'm not going to show you the radiographs.

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Basically, the radiographs demonstrated

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findings of a left hip effusion, which

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I think is well illustrated here on this

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coronal fluid-sensitive fat-suppressed sequence.

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We're looking at the left hip

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here and the right hip over here.

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What do we notice immediately?

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Well, I immediately notice that there is a

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pretty good-sized effusion on the left side.

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And one word I want to point

0:30

out about hip effusions.

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Hip effusion is probably the single

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most important thing that you should

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be looking for when a child comes in

0:38

with hip pain on a plain radiograph.

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Because hip effusion means that

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there's something wrong with that hip.

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You don't know what's wrong.

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It could be an infection, it could be

0:46

avascular necrosis, it could be something

0:47

like this, but there's something that's

0:49

irritating that area and that joint.

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And the body reacts to any sort of irritation

0:54

by sending fluid and inflammation to it.

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So when you have a joint effusion,

0:59

you don't know what's causing it,

1:00

but you know there's something wrong.

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So that's why the plain

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radiographs are important.

1:04

are really important for you to look

1:05

for subtle changes of hip effusion.

1:07

So once you have it, then you get other

1:09

imaging, ultrasound, MRI, what have you,

1:11

depending on your clinical suspicion.

1:13

So I just want to throw that out there.

1:15

So this patient has a left hip effusion.

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And what do we notice besides the hip effusion?

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Well, there is a geographic area.

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I call it geographic because I feel like

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I can take a marker, like this, and I can go

1:35

like that.

1:36

All the way around, like this, like

1:39

this, and define the area of abnormality.

1:44

So, what's going on over there?

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Well, we know it's edematous, and it's

1:49

geographic, and it has caused a joint effusion.

1:51

What if we gave contrast?

1:53

What does this look like if we give contrast?

1:56

Let us go ahead and bring the

1:57

contrast images over here.

2:00

And there is a little bit of enhancement there.

2:03

Let me convince you that it really does enhance

2:05

by bringing you a pre-contrast image. I'll put

2:09

this back here. A pre-contrast image is here.

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One word of warning is, if you see

2:13

something bright on a post-contrast

2:15

image, how do you know it's actually

2:17

enhancing unless you have a pre-contrast?

2:19

Because it may have been intrinsically

2:21

bright, T1 bright to begin with.

2:23

Always compare your post-contrast

2:24

images with your pre-contrast images.

2:27

And here I think you can be convinced that

2:29

this, in fact, is an area of enhancement.

2:31

It's not just this area that's

2:33

enhancing, but also the synovium.

2:36

is enhancing.

1:20

Well, there is a geographic area.

1:24

I call it geographic because I feel like

1:26

I can take a marker, like this, and I can go

1:35

like that.

1:36

All the way around, like this, like

1:39

this, and define the area of abnormality.

1:44

So, what's going on over there?

1:47

Well, we know it's edematous, and it's

1:49

geographic, and it has caused a joint effusion.

1:51

What if we gave contrast?

1:53

What does this look like if we give contrast?

1:56

Let us go ahead and bring the

1:57

contrast images over here.

2:00

And there is a little bit of enhancement there.

2:03

Let me convince you that it really does enhance

2:05

by bringing you a pre-contrast image. I'll put

2:09

this back here. A pre-contrast image is here.

2:11

One word of warning is, if you see

2:13

something bright on a post-contrast

2:15

image, how do you know it's actually

2:17

enhancing unless you have a pre-contrast?

2:19

Because it may have been intrinsically

2:21

bright, T1 bright to begin with.

2:23

Always compare your post-contrast

2:24

images with your pre-contrast images.

2:27

And here I think you can be convinced that

2:29

this, in fact, is an area of enhancement.

2:31

It's not just this area that's

2:33

enhancing, but also the synovium.

2:36

is enhancing.

2:37

So where you had joint effusion

2:38

before, the synovium is rotated.

2:41

So you have synovial enhancement, joint

2:42

effusion, and this funny geographic area of

2:46

abnormal signal sort of in the mid femoral head.

2:50

So this is a condition called

2:54

idiopathic chondrolysis.

2:56

Idiopathic chondrolysis, as the name would

2:58

imply, is unknown why it happens, but there

3:01

actually is a very high association with

3:04

juvenile idiopathic chondrolysis.

3:08

arthritis, or JIA, juvenile

3:11

idiopathic arthritis.

3:12

In fact, the several cases that I

3:14

have seen, eventually those patients

3:16

have been diagnosed with JIA.

3:19

So when you see a pattern like this, first

3:22

recognize it for the condition that it is,

3:26

which is idiopathic chondrolysis, and you

3:29

want to mention, hey, could this be JIA?

3:32

If so, maybe the rheumatologist should

3:35

see this patient, maybe some arthritis

3:39

markers should be run, as a blood test.