0:01

It's a 55 year old woman who injured the wrist

0:05

on a countertop in 2016. Okay,

0:10

we're back here at 1.5 T. We put an image up with an arrow on it,

0:14

so it's no secret what's happened here.

0:17

The audience said torn triangular fibrocartilage disc.

0:22

And that is actually not untrue.

0:24

There is a tear in the central third of the T F C.

0:28

That is absolutely true. Um,

0:31

someone else said that the extensor carpi naris was subluxed

0:37

and I, I give a fair amount of latitude to the extensor carris,

0:41

but I don't like to see it displaced over the ulnar styloid.

0:46

I'll allow it to be eccentric in the groove. So it can be over here,

0:50

it can be over here, but I don't want it over here.

0:53

So whoever said that is absolutely correct.

0:57

And what that means is the extensor carpi NARS sub sheath,

1:01

which is connected to the capsule and the ul, no meniscus holo is deficient.

1:07

So this is peeled off the periosteum and has allowed the E C U to

1:12

displace or sublux or dislocate.

1:16

Now the other thing I do when I see this in the short axis projection

1:21

is I look at the radial ulnar congruity. I want

1:28

the center of the ulna and the center of the radius to line up

1:33

this way

1:35

or this way so that they're right in line with one another. In other words,

1:39

the middle of this right here,

1:41

the middle of this should be lined up with the middle of this.

1:45

And they're pretty close, but they're not perfect.

1:48

So when I have E C U displacement,

1:52

I am worried about radial ulnar micro instability or instability.

1:59

And what I do in that circumstance is I pull up all my sequences and I look at

2:03

the volar. There's the T ffc, by the way,

2:06

it's triangular in the short axis view.

2:08

I call up my short axis projections and I look at the volar radial

2:13

ulnar ligament, which is this, and it's intact.

2:17

See if we get another better shot at it. There it is.

2:22

It's intact. The volla radial in the ligament.

2:24

There's your triangular fibrocartilage. That's why it's called triangular.

2:28

It's triangular in the short axis projection.

2:31

So the vola R U j or R u l is

2:36

intact. But if I'm worried that it's not intact,

2:39

I will bring the patient back and do steep pronation and supination views.

2:43

And I'll compare the excursions of the ulna on the two sides

2:49

and they should be symmetric. So this case, um,

2:54

has a couple of sexy findings and that that is one of the more sexy findings

2:59

and one of the more important teaching points. Um,

3:02

your colleagues that picked up on this triangular fibrocartilage tear a couple

3:06

of noteworthy points. First,

3:11

it's associated with very little swelling or inflammation.

3:15

We call up some of the other sequences like this one, the gradient echo,

3:19

and there it is. This is where most of the traumatic tears occur.

3:25

Traumatic tears are divided into a central B peripheral,

3:31

C distal or proximal.

3:34

The distal proximal attachments best seen on the sagittal and D,

3:38

the very rare detachment from the radius.

3:42

I see that maybe once a year.

3:44

And don't confuse the cartilage of the radius for a vertical tear.

3:49

Now the tear is over here in the central third.

3:51

So this is a traumatic Palmer one, A one being traumatic,

3:56

A being central tear. Now what's a Palmer two?

4:01

A Palmer two is for chronic ulnolunate

4:06

abutment syndrome. In A two, you have

4:12

a thinning, B

4:17

malacia, ul, no malacia and LU NATO malacia.

4:21

So malacia here and malacia here.

4:24

C A T F C tear

4:30

D would be

4:34

dissolution or disruption of the ul, no triquetral ligament.

4:39

So LT, ligament and E would be slack wrist.

4:44

So that's a chronic scenario. So Palmer two, chronic Palmer,

4:49

one traumatic.

4:51

So now let's go back to the less interesting part of the case,

4:56

which is the main reason why we're here clinically.

5:00

And that is the patient has sustained a triquetral fracture.

5:05

Now, like our macro fracture that we saw before,

5:10

you can see the gapping right here.

5:12

There's the gap between one fragment and the other fragment. Here's the,

5:17

here's the macro fracture. Now you may or may not see this on a radiograph.

5:22

This is so easy to see on an M R I,

5:26

but it takes a little bit of training to actually see that line until the

5:30

sclerosis kicks in. Then you'd have a sclerotic line over here.

5:36

You'd have a sclerotic line over here, a sclerotic line over here,

5:39

and you'd see the gap in between. But without that sclerotic line,

5:43

all the edema, let's go back.

5:45

All this edema has obscured the dias static separation of this

5:50

fracture. You kind of see the line right here, right there, there, there,

5:55

there. And all of this

5:56

Tissue right here. I'm gonna color it in for you.

6:00

This is the gap in the fraction. And where's the fragment?

6:06

This is all the fragments right here, this portion,

6:09

and there's the cortex of the fragment right there. I colored it over. In fact,

6:13

I'm gonna color the cortex in yellow.

6:16

Now I'm gonna take it away and you're gonna be able to see it.

6:21

One edge of the fracture, the gap, the other piece of the fracture,

6:26

which is emus and it's cortex. So it's a macro fracture,

6:31

minimally displaced of the triquetrum. And then number two,

6:37

incidentally noted perforation of a central third of the T F C,

6:41

likely Palmer one A.

6:44

And then this patient also had subluxation of the E C U

6:49

with stripping and deficiency of the extensor Carpe RIS sub sheet.