0:00

And this is a 49 year old man with wrist pain in a scapholunate area on and off

0:05

after a fall two years ago and getting worse. So,

0:09

you know, when I hear scapholunate, I go right to the scapholunate ligament,

0:14

which has three components.

0:17

It's got a LAR Co,

0:21

which can be either trapezoid or band like this one's kind of band

0:26

like. And then you get the membranous portion,

0:29

which is kind of T-shaped. And then you get, sorry,

0:33

this is the vola component here, which is more trapezoid shaped.

0:39

Then the membranous component, which is more T-shaped,

0:44

hard to appreciate here, maybe here you could appreciate it.

0:47

And then as you get back, um, into the dorsal aspect, it's more band like.

0:52

And there's the band that, that one is, is definitely clear.

0:57

Let's look at the triangular fibrocartilage. Here's the radial attachment.

1:01

Here's a lunate ligament right here. An ul, no lunate attachment.

1:05

Here's an UL no triquetral attachment and there is the foveal and

1:10

styloid attachments can see them on the gradient echo as well.

1:13

There's your foveal attachment right there. And um,

1:18

styloid attachment probably right there.

1:21

This is a little bit of cartilage from the radius. Uh,

1:24

the LT ligament is very small and stubby. Uh, in this patient. It's hard to see,

1:29

but it's right there. There's no widening whatsoever. There's no widening here.

1:34

So let's go back to the history wrist pain and escap lunate area.

1:38

There are innumerable pseudocyst, but they're not near the joint.

1:42

So these are not what I would describe as arthropathic erosions,

1:47

arthropathic cysts, arthropathic pseudocysts, they are,

1:50

they are more compatible with friction related and there's a lot of friction

1:54

going on in your hand 'cause you're twisting and turning and grabbing all day

1:58

long. So not a lot of, uh, interesting.

2:04

Um, symptom related findings here.

2:06

There is a beautiful view of one of the lar extrinsics

2:11

and these make an inverted V right here. Here's one limb of the V.

2:15

Here's the other limb of the V.

2:17

Let's look at the dorsal extrinsics to see if those pop out for us.

2:22

You can kind of see one right here.

2:24

And they're usually more horizontally oriented. They'll make a sideways V.

2:28

Here's one of the limbs of the v. The other limb, hard to see.

2:32

There's another dorsal extrinsic right there.

2:36

But those don't seem to really be the problem.

2:39

So we've looked at the intrinsics and the extrinsics and,

2:43

and those are not what's, what's causing our problem?

2:47

What is causing our problem is this.

2:51

We've got a fracture of the radial styloid,

2:54

a so-called Barton type fracture, which you've all heard that expression before.

2:59

It's slightly convoluted.

3:01

So that in itself is going to give you the symptom complex that

3:06

resembles a scap o lunate injury. And you'd say, okay,

3:10

game over the question, the clinical question is, is answered.

3:16

Now I

3:19

think it would be easy to say that here is the comminuted little fracture

3:23

fragments of the radial styloid.

3:25

But let's put up the short axis view 'cause we gotta complete the study.

3:30

And here's our sagittal. I'm gonna flip our sagittal right side up

3:39

and it looks a little busy back here.

3:43

Now I like to see my lunate and my capitate and my third metacarpal and my,

3:49

my radius lineup nicely with each other so I can make a straight line through

3:53

them. Something akin to this,

3:56

but I think you can appreciate that the technologist did this to the wrist.

4:00

They slightly dorsiflexed it and you can see that right here.

4:05

But the alignment is otherwise just fine. So let's do a little,

4:08

a little scrolling in this case because anytime you have an injury to the

4:13

to the radius,

4:15

you always have to be worried about an injury to the first

4:20

extensor compartment, especially with a a barton's fracture.

4:25

And that would affect compartment extensor number one,

4:29

which is the abductor lysis,

4:31

longest extensor lysis brevis pay no attention to this structure here,

4:35

which represents the radial artery or this one, the flexor carp radialis.

4:40

So this one is of interest. It's a bit gray over here.

4:44

It's nice and black over here. So this is just magic angle effect,

4:49

it's artifact and our compartment extensor number one is fine. How about two?

4:53

So we got a abductor lysis, long extensor lysis previs, longest previs,

4:58

then longest extensor carpi radis longus and extensor carpi

5:03

radiologist BVIs. Those look fine.

5:06

But then we get into the third extensor compartment.

5:10

That does not look fine.

5:11

That is not black on either the T two or on the T one.

5:16

Now granted you can have gray tendons on the T one from magic angle effect,

5:21

but it shouldn't be gray on the T two weighted image with all of this

5:24

irregularity. So at some point,

5:28

at some point be it this trauma or a prior trauma,

5:32

something happened to lister's tubercle that allowed it to

5:37

damage, to damage the extensor, uh, uh,

5:42

lysis longus.

5:43

Now sometimes you can see extensor lysis pathology as it courses

5:49

over the extensor carp,

5:51

radiologist longus and brevis if you've had a prior injury.

5:54

And this reticulum gets very

5:57

Contracted and snug.

5:58

And this is what's known as wrist intersection syndrome.

6:03

And that's the differential diagnosis here.

6:05

Old lister's tubercle fracture versus wrist

6:10

intersection syndrome from a prior injury, either one.

6:15

Let's keep going. Now we've got the extensor digitorum over here,

6:20

uh,

6:20

the extensor digit minimi and then the extensor carpinus and

6:25

those, those are all present and, and accounted for.

6:30

So let's see if there's anything else that that needs to be commented on

6:35

here. Um, I don't think so.

6:38

You can see that there is this funny little cystic change in lister's tubercle

6:42

that tells us something either post-traumatic and inflammatory has occurred

6:47

here or just post-traumatic with friction has induced a cystic change

6:52

at lister's. Tubercle.

6:54

And this is the extensor lysis longus coursing over the top of it.

6:58

Let's go back to it one more time so you can see it.

7:02

This is the abnormal E P L and somebody with this is gonna have trouble

7:06

extending their thumb. So this is a tricky case.

7:09

You get sucked into the barton's fracture,

7:12

you get sucked into the first extensor compartment and you fail to identify

7:17

a major finding,

7:18

which is a high grade injury or tear to the extensor lysis longness

7:23

with abnormalities of lister tubercle whose differential diagnosis I gave

7:28

to you. Let's just take one more scroll through

7:35

the extensors.

7:39

There was an extensor carris injury and I think

7:44

I'm gonna pass over it right now because we've got a lot more to cover. And, um,

7:49

let's keep going. Shall we.