0:01

Now we've gotten to Salter-Harris III.

0:03

We've talked about I and II; now it's time for III.

0:07

And for this one, I'm going

0:08

to show you knee images.

0:10

The image on your left is a plain radiograph.

0:12

The middle image is a coronal reconstruction

0:15

of a CT scan that was axially acquired.

0:18

The image on the right is our

0:20

dual echo steady-state MR image.

0:24

Let's look at the plain film first.

0:27

On the plain film, we see that there is a

0:30

lucency that's sort of vertically and obliquely

0:32

oriented through the epiphysis, exiting out

0:35

into the joint space with maybe a few flecks

0:38

of bony fragments here, perhaps in the joint.

0:42

But that fracture line

0:43

extends to the medial physis.

0:45

The medial physis itself is widened.

0:48

Compare that to the lateral

0:49

physis, as you see over here.

0:51

There is subtle widening on that side, so

0:53

we know this must be a Salter-Harris injury.

0:55

The fact that it doesn't go through the

0:57

metaphysis, at least on the plain radiograph,

1:00

tells me that we're looking at a Salter-Harris III

1:03

injury, the beginning of what we classify as

1:06

a longitudinally oriented Salter-Harris injury.

1:10

So here's a CT scan reconstruction.

1:12

As we go through, indeed, we see that there

1:14

is widening of that physis, extending

1:18

obliquely and then vertically down

1:20

into the epiphysis and exiting

1:22

into the articular surface.

1:24

As we go back and forth, we notice

1:26

that indeed that physis is wider

1:29

than the adjacent contralateral side

1:31

over here on the lateral aspect.

1:34

And what do we see on the MR?

1:36

Something very similar.

1:37

Again, we see fluid and edema

1:39

here where the physis should be.

1:42

Compare that to the normal

1:43

appearing physis on the other side.

1:45

So there's separation here at the

1:47

physis, and the fracture line extends

1:50

vertically downwards into the joint space.

1:53

So a nice example of a Salter-Harris III

1:56

vertical oriented or

2:00

longitudinally oriented fracture.

2:02

Much more likely to have bony bridging

2:06

later on in life than the other

2:07

two that we've discussed so far.