0:01

Okay, we're gonna uh, start again with the second part of

0:05

today's, uh, discussion on the wrist.

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And my job over the next, uh, 40 to 45 minutes

0:13

is to discuss the triangular fibrocartilage complex.

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TFCC is the abbreviation that we use.

0:22

What I plan to do is to discuss its anatomy in some detail

0:26

and then bring you up to date with regard

0:29

to the patterns of failure.

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Now again, to understand pathology, you certainly have

0:36

to start with anatomy.

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So let's review again

0:40

a little bit about the various compartments

0:43

or joints of the wrist.

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It is not a single joint.

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It consists of a series of compartments

0:50

and which you should always remember,

0:52

whether you're interpreting conventional radiographs,

0:56

CT scans, Mrs.

0:57

Arthrograms, what have you.

0:59

So the major compartment

1:01

of the wrist is the radial carpal compartment, v-shaped

1:06

separating the distal radius from the proximal carpal row.

1:12

There is a second joint also C shaped,

1:17

separating the distal radius

1:19

and the distal oma known as the distal

1:22

or inferior radial the joint.

1:25

And in many persons, particularly the young persons,

1:28

that joint separated from the radial carpal compartment

1:32

by an intact triangular fibrocartilage complex.

1:37

There is a third joint, one of my favorites in the wrist,

1:40

the pisiform triquetral joint.

1:43

You can see it here in the section.

1:46

It may look small to you in this drawing and in the section,

1:49

but it's one of the larger compartments explaining the

1:53

mobility of the pisiform.

1:55

With respect to the triquetrum,

1:59

there is a mid carpal compartment,

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which makes its way in an irregular fashion from the radial

2:05

to NAR aspect of the wrist shown here,

2:09

separating the proximal um, bones

2:14

and distal bones of the carpus.

2:17

And you can see that the mid carpal compartment is separated

2:20

from the radial carpal compartment by those

2:23

interosseous ligaments about which we spoke.

2:27

As we move a little bit distally,

2:28

there is a common carpal metacarpal compartment,

2:32

generally a single compartment, sometimes double

2:35

with inter metacarpal extensions

2:38

and a separate first carpal metacarpal compartment.

2:42

I introduced that anatomy

2:44

because I think it's important for you

2:46

to recognize particularly what's in the radial carpal

2:49

compartment near the triangular fibrocartilage complex.

2:54

A drawing done years ago shows you the radial carpal

2:58

compartment opened up owing

2:59

to a flexed position of the wrist.

3:02

You can see here the distal radius.

3:04

This then is the triangular fibrocartilage disc,

3:08

and here is an opening.

3:09

We'll be talking about the presty recess

3:12

of the radiocarpal compartment.

3:15

Uh, there are also lar radial recesses

3:18

that you can appreciate.

3:19

There we go ahead

3:21

and look at that here with a coronal section.

3:25

This then the radial carpal compartment,

3:27

the triangular fibrocartilage shown here.

3:30

Here's the pre recess.

3:32

It extends over, becomes intimate

3:34

with the ulnar styloid process and passes just beneath it.

3:39

So if you ever wondered why the earliest erosions

3:41

of rheumatoid arthritis of the ulnar yl tend

3:45

to be on the lar surface, you now know your answer.

3:48

It's due to synovitis occupying the pre resets.

3:53

And then there is a separate cavity here.

3:55

We just talked about the bioform triquetral, that

3:58

as I will show you can communicate

4:01

with the radial carpal compartment here.

4:05

One final section

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and just like the drawing above it,

4:08

that is the pre styloid recess

4:10

of the radial carpal compartment.

4:13

And as is typical in many of the cadavers we've sectioned,

4:16

you can see there's an abnormality

4:18

of the triangular fibrocartilage disc.

4:22

Now here is my drawing again of the wrist

4:25

with the various compartments labeled,

4:28

and I put this in this particular talk

4:31

to introduce the concept.

4:33

Concept that certain communications are considered normal

4:36

among these compartments at any age.

4:40

I would emphasize two communication

4:42

between the radial carpal compartment

4:44

and the pisiform triquetral compartment

4:47

is a normal finding at any age,

4:50

however, I'm gonna show you one lesion

4:53

that enlarges the opening between these two compartments.

4:57

The other communication, which is normal at any age, is

5:01

between the mid carpal

5:02

and common carpal metacarpal compartment

5:05

and inter metacarpal extensions.

5:08

This generally is normal at any age.

5:12

There are certain communications

5:13

that may be asymptomatic in older persons.

5:17

The first is between the radial carpal and the distal

5:20

or inferior radio in their compartment.

5:23

Now, this is a diagnostic problem

5:25

because our job today is to try

5:27

to sort out when this is asymptomatic

5:30

and when it may be traumatic and symptomatic,

5:34

but it can be a asymptomatic finding in older people.

5:39

And unfortunately the same is with the second communication

5:42

that may be asymptomatic

5:45

and older persons radiocarpal.

5:48

Mid carpal certainly can occur owing to degeneration

5:52

of the intervening scap lunate and lunar triquetral

5:56

Interosseous ligaments.

5:58

So let me just show you

6:00

what a normal arthrogram would look like.

6:02

The radiocarpal compartment iodinated contrast material,

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this is the pre recess of the radiocarpal compartment

6:11

approaching the ulnar cy.

6:13

And this is contrast, which

6:15

normally has entered the pisiform triquetral compartment.

6:20

These are the volar radial recesses.

6:23

So this is an entirely normal study.

6:26

Now this study, I'm showing you only the ulnar side.

6:29

This followed a radial carpal arthrogram

6:32

and is clearly abnormal.

6:34

This contrast is in the radiocarpal compartment.

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There's the pre styloid recess,

6:39

but it's passing through a traumatic full thickness

6:42

perforation of the disc

6:44

of the triangular fibrocartilage complex communicating

6:48

with the distal radio in the joint.

6:51

As we look here, we can see that this is extending

6:54

through a portion of the luno tri ral interosseous ligament,

6:59

heading up and filling the mid carpal compartment.

7:03

We used to do a lot of wrist arthrograms, not combined

7:06

with CT or MR, but just standard arthrograms.

7:11

And then we combine them with subtraction techniques.

7:14

So I just wanted to show you one example.

7:17

The radius would be here, the only here,

7:20

this is the coronal image.

7:22

We've injected the radiocarpal compartment,

7:24

this vola radial recesses.

7:27

We followed over.

7:28

Here's the pre recess

7:31

of the radial carpal compartment, one abnormality here

7:35

through the triangular fibrocartilage disc

7:38

with contrast reaching the distal radial in the joint.

7:42

We see here communication, which can be normal

7:44

with the pisiform triquetral compartment,

7:48

but now an abnormal bit of contrast

7:52

in the mid carpal compartment,

7:53

which should not normally communicate

7:56

with the pisiform TriCal.

7:58

Later on, I'll explain exactly why that occurred. I.