0:00

Let's look at another

0:01

injury involving the physis.

0:04

Here we have multiple projections of the right

0:08

knee in a 14-year-old boy with a knee injury.

0:12

Here is a frontal projection.

0:14

We notice that there is a lucency right

0:18

here going through the epiphysis of the

0:21

distal femur, sort of separating the

0:23

lateral condyle from the medial condyle.

0:26

And the line goes just like this

0:29

over here and hits the physis.

0:32

And I can sort of visualize that this

0:35

physis on the medial side may be slightly

0:38

wider than the physis on the lateral side.

0:42

Remember, the physis is a disc-shaped structure,

0:44

so you're actually seeing two projections, one

0:47

barely over here and one over here, because

0:50

you're seeing one surface versus the other,

0:53

um, as we sort of obliquely view the image.

0:56

But over here, I can imagine that this

0:58

physis may be slightly wider than the

1:00

physis, either one of these physes

1:01

on the right, on the lateral side.

1:03

Let's see how obliquity helps us.

1:06

Here's an oblique view, and we can see

1:09

that component of the epiphysis much better.

1:13

Not only do we see that, but we also

1:14

see the little fragmentations here,

1:16

so it may be somewhat comminuted.

1:18

And we have, again, entering the physis,

1:20

maybe slightly widening of that medial physis.

1:23

Hard to say what's going

1:24

on the lateral physis.

1:26

For that, we've got the other obliquity.

1:29

On the other obliquity, the fracture

1:31

line really is very different.

1:33

Difficult or impossible to see.

1:35

So this sort of illustrates another point.

1:37

When we do have knee injuries, sometimes

1:40

a simple frontal and lateral view may

1:42

not be adequate to show you the injuries.

1:45

You may need to get oblique views to really

1:47

profile everything that needs to be seen.

1:51

So this obliquity doesn't help us very much.

1:53

Finally, here's a lateral view.

1:56

On the lateral view, we don't

1:57

see the fracture so well.

1:59

But what we do see, maybe we see a little bit

2:01

over here, it's hard to say, but what we do

2:03

see is this huge joint effusion over here.

2:06

And it's a very dense joint effusion.

2:07

It has an effusion that's similar

2:09

in density to the soft tissues around it.

2:13

And the rest of the knee looks okay.

2:15

In the next vignette, we'll go over

2:17

how this looks both on CT and on MRI.