0:00

It's a companion to TFC Roman numeral II

0:03

palmar grading classification system.

0:07

We have a palmar II C because the TFC is not only

0:13

thinned, it's torn or ruptured in its inner third.

0:18

It's got a full-thickness tear.

0:19

There's lunatomalacia, there's ulnar malacia,

0:22

but the lunotriquetral ligament is intact.

0:25

Palmar II C.

0:27

But there is quite a bit of

0:29

irregularity throughout the carpal area.

0:32

There are some pseudocysts, there are some erosions.

0:35

And that is from the scapholunate instability

0:40

and tear of the scapholunate ligament.

0:41

So let's scroll that for a moment.

0:43

We start out dorsally.

0:45

The strongest part of the ligament

0:46

right here, there's a big gap or hole.

0:49

The membranous portion or central

0:50

portion, there's also a gap or hole.

0:53

The ventral portion, perhaps there's a

0:56

little bit still intact, not as bright.

0:59

Not as wide.

1:00

There's some low-signal intensity material there.

1:02

But clearly, we have scapholunate insufficiency, which

1:06

has contributed to some generalized degeneration

1:10

of the carpus, some swelling of the carpus, and

1:14

even a little bit of hypertrophy of the radial

1:15

styloid, which is one of the earliest signs seen

1:20

in slack wrist or scapholunate advanced collapse.

1:23

Now, another major reason for showing this

1:26

case is the patient had ulnar-sided wrist pain.

1:29

She's 42 years old, and we've got this large, bright

1:32

object that's surrounding a ball, the pisiform.

1:36

Let's have a look at the piso-triquetral recess.

1:42

It's got a bursa in it.

1:44

That bursa is synovial-lined.

1:46

Now, everybody has some element

1:50

of piso-triquetral disease.

1:52

It's kind of like the acromioclavicular

1:54

joint of the shoulder.

1:55

Nobody has a normal one after age 20.

1:58

So when is it symptomatic?

2:00

When you have irregularity and arthrosis.

2:03

When you have a mass that's under

2:04

pressure or dissecting, like this one.

2:07

When you have large pseudocysts

2:10

in the triquetrum, like this one.

2:12

So most likely, piso-triquetral disease, in this

2:16

case, with a large piso-triquetral cyst coming right

2:20

out of the bursal space, has contributed to this

2:24

patient's TFC abutment syndrome, Roman numeral II C.

2:30

So we have a third problem.

2:33

We've got the TFC problem, we've got the

2:35

scapholunate ligament problem, and now we've

2:37

got the piso-triquetral articulation problem.

2:42

We better finish checking out the ulnar side

2:45

of the wrist, because we're not done yet.

2:47

We've got one more major area that produces ulnar

2:51

side of wrist pain, although more commonly in kids.

2:55

This is not a kid, but still pretty young; 42's young.

2:58

Let's have a look.

3:01

So you are looking at the dorsal aspect of the wrist.

3:03

This would be dorsal, this would be palmar, T1, T2.

3:06

I think I'll flip them for you.

3:08

I think it'll make it a little easier.

3:12

Actually, now I had them the right way to begin with.

3:15

Now they're flipped.

3:16

So this is dorsal, this is palmar.

3:19

So what is that other area that I'm interested in?

3:23

It is the extensor carpi ulnaris.

3:27

I'm gonna make this a little smaller

3:29

so you can see a little better.

3:30

That is a very common cause of ulnar-sided wrist pain.

3:34

I'd like to draw for you a little bit,

3:36

because here's a source of constant confusion.

3:41

Here's our ulna, you can see, um, sometimes

3:43

a pretty good drawer, sometimes not so much.

3:46

And there inside our ulna is a tendon.

3:53

We'll make our tendon orange today.

3:56

Now that tendon is secured by something

3:58

called the extensor carpi ulnaris.

4:02

Subsheath.

4:03

I'm gonna make the subsheath blue.

4:06

It hugs very close to the ECU.

4:09

That's really important.

4:12

The subsheath is often incorrectly ascribed

4:17

the name extensor retinaculum and vice versa.

4:21

The extensor retinaculum is much thinner.

4:25

I think I'll make it brown, and I think I'll

4:27

also make it a lot thinner just to be accurate.

4:30

So let me make it thinner for you.

4:32

So here is the extensor retinaculum, which is

4:35

often kind of dirty and irregular and often inflamed.

4:40

So now let's have a look.

4:43

There is our groove, our ulnar groove.

4:45

We want to assess the depth of the

4:47

groove, the smoothness of the groove.

4:49

There is our extensor carpi ulnaris.

4:53

It often has some signal inside

4:55

it, because it gets used a lot.

4:57

And sometimes, because of magic angle effect or the

5:00

55-degree artifact, you'll see some signal in it.

5:02

But not linear.

5:04

Slit-like, coast-to-coast, surface-to-surface signal.

5:10

And there it is.

5:11

From the dorsal surface to the palmar surface.

5:14

That's a split.

5:16

So there's a split tear of the ECU with everything

5:20

else going on in this soup of pathology.

5:24

Where is our subsheath?

5:27

Right there.

5:30

That's our subsheath.

5:31

Hugging close to the ECU.

5:34

That's what helps secure it.

5:36

The retinaculum, not so much.

5:38

Where's the retinaculum?

5:39

This irregular, fibrillated, somewhat

5:42

dirty structure, more superficial to it.

5:46

Well, that concludes this companion vignette,

5:49

in which we've got a myriad of pathology.

5:52

We like to be brief on these, but we've

5:54

got TFCC, Roman numeral II C, scapholunate

5:59

dissociation, extensor carpi ulnaris split tear,

6:02

and piso-triquetral arthritis and bursitis.

6:06

Let's move on, shall we?