0:00

So when we talk about the triangular fibrocartilage

0:03

complex, currently most people believe there are sticks,

0:07

ingredients, which I have listed here,

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the triangular fibrocartilage disc itself, the dorsal

0:14

and lar radial nar ligaments, the ulnar meniscal homolog,

0:18

the ulnar collateral ligament,

0:20

which I'm not gonna be dealing with very much.

0:22

It's an unimportant structure,

0:25

the extensor carpi naris tendon.

0:27

I'll talk briefly about that

0:29

and the lar ulnar carpal ligaments.

0:32

And I just wanted to provide you with a few coronal sections

0:35

and cadavers showing you the dorsal radial ligament,

0:39

the triangular fibro cartilage disc,

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and we'll talk about its lamina.

0:44

And then on the vola aspect, some of the

0:48

ulnocarpal ligaments that you may see,

0:52

this is an appearance of what the triangular, fibro, uh,

0:55

cartilage disc would look like.

0:58

So let's go over its anatomy that disc attaches

1:03

to articular cartilage,

1:04

and that will become important

1:06

as I'll show you in a, in a minute or so.

1:08

It has two attachments to the distal ulna.

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The proximal attachment, also called the foveal lamina,

1:16

okay, is the more important of these two.

1:21

The distal one, also called the styloid.

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Lamina, is intimate with the pre recess

1:27

of the radial carpal compartment beneath the two

1:31

looser connective tissue,

1:33

which was called the ligamentum submentum.

1:36

The definition of this has changed somewhat in recent years.

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Now, sometimes you will get an image

1:42

where you can't separate out the lamina,

1:45

in this case a little bit of irregularity of the disc.

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But in many images you'll be able to separate the lamina,

1:52

the foveal lamina, and the styloid lamina.

1:57

The vascularity of the triangular fibrocartilage disc is a

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peripheral vascularity, much like the meniscus of the knee.

2:06

And therefore in the periphery when you see abnormalities,

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this is the zone of repair.

2:12

It's called the repair zone.

2:14

But if you deal with abnormalities in the central aspect

2:17

of the triangular fibrocartilage disc,

2:20

much like in the avascular region of a meniscus,

2:24

generally you debride the abnormality and do not repair it.

2:30

Now here I've kind of given you a rough drawing

2:32

of the radius, the disc of the triangular fibrocartilage,

2:37

and I wanted to show you the radial ulnar ligaments

2:41

because there's an important way of differentiated

2:45

among the disc.

2:46

And these ligaments,

2:48

the triangular fibrocartilage disc shown here,

2:52

attaches to cartilage.

2:53

So you should be able to see a thin rim of altered signal

2:59

Paralleling the radius that is cartilage.

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But when you talk about the dorsal

3:05

and lar radi ulnar ligaments, they attach to bone.

3:09

So that's how you can separate out the radial nerve

3:12

ligaments from the triangular fibrocartilage.

3:17

Now, I wish the anatomy was that, uh, standard

3:22

and that simple, but it is not.

3:24

In the last 10 years, there have been a number of articles

3:27

that have indicated that if you look closely at the

3:31

triangular fibrocartilage complex, it consists

3:35

of superficial and deep fiber systems,

3:38

and some believe it also has an intermediate

3:43

fiber system located between these two.

3:46

And I'm gonna just deal with the superficial

3:48

and deep fiber system.

3:50

The upper drawing is showing you the superficial fiber

3:54

system showing you portions of the volar

3:57

and dorsal radial and the ligaments.

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They, they're superficial components attached

4:03

to the ulnar yl.

4:05

The lower drawing is showing you the deep portion, okay?

4:10

The deep system, which consists of the deep fibers

4:13

of the volar and dorsal radio in their ligaments,

4:17

and they attach to the ulnar fovea.

4:21

So this is generally accepted.

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Now, the meniscus homolog,

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and I'm gonna show you a picture of it in a minute,

4:27

is now considered to be at least beginning

4:31

at the radial attachment, uh, uh, of

4:35

that superficial dorsal radial the ligament.

4:38

So let's look at that.

4:40

That is the position now of the meniscus.

4:44

Mila again, some

4:46

of our visiting scholars have done some

4:47

beautiful anatomic work.

4:50

Uh, and there's one image.

4:51

I'm gonna show you some more images in a moment.

4:54

This then is the meniscus holo at its proximal

4:58

radial attachment.

5:00

Now it's gonna swing over

5:02

and we're gonna see three other components

5:05

to the meniscus homolog.

5:06

There's a styloid component right here,

5:10

triangular in shape, intimate with the presty recess.

5:15

Remember, that communicates with the radiocarpal compartment

5:19

as we go, a little bit more distal adjacent

5:21

to the triquetrum.

5:23

This is the collateral component.

5:25

So you can see that here, see attaching to the triquetrum

5:30

and extending out more distally as the distal insertion

5:34

with attachments also to the hamate

5:37

and to the base of the fifth metacarpal.

5:39

So this meniscus al analog starts, radially, extends over

5:44

with attachments to the ulna,

5:46

and then swings distally attaching to some

5:50

of the carpal bones as well as the fifth metacarpal.

5:55

Now we also can

5:56

See another component

5:58

of the triangular fibrocartilage complex,

6:01

the volar ulnocarpal ligaments.

6:04

I've already mentioned there are three of these,

6:05

but only two of them are part

6:08

of the triangular fibrocartilage complex.

6:10

There's a volar ul no lunate ligaments shown here,

6:16

and a lar olo triquetral ligament.

6:19

We see some of its attachments,

6:21

these ligaments perhaps better shown here in a coronal

6:24

section attached to the disc

6:27

and swing out in this case, the ullo triquetral ligament

6:31

attaching to the triquetrum.

6:33

Another section would show you the volar

6:36

or no lunate uh, ligament attaching to the lunate.

6:41

These are important ligaments,

6:42

and some of the abnormalities

6:44

of the triangular fibrocartilage complex involve those

6:48

ligaments.