0:00

Well, let's move now to the spaces perhaps

0:03

that you're most familiar with, the scap, lunate

0:06

and lunar triquetral spaces.

0:10

And let's talk about those ligaments, particularly

0:14

the scap lunate interosseous ligament.

0:18

As you can see, if we do a look at it in the sagittal plane,

0:22

there is a dorsal, a central or proximal portion

0:26

and a LAR portion.

0:27

And that would be the same for the luno

0:30

triquetral interosseous ligament.

0:33

With regard to the scapholunate interosseous uh, ligament,

0:37

the dorsal portion is the thickest strongest

0:41

and most critical.

0:44

So that is what you wanna remember.

0:47

The central portion is made of fibrocartilage

0:50

and is not a true um, uh, ligament.

0:54

And that's the one that in fact will tear even

0:57

with degenerative changes.

0:59

Now, if we go to the lunar triquetral,

1:02

I would tell you it's the opposite.

1:04

The volar aspect of that ligament is in fact the strongest.

1:09

Now when you look at these ligaments

1:11

and uh, uh, MRR, okay, what you will see is that

1:16

although you would like them to be

1:18

low signal without any intermediate signal,

1:21

that often they do have circular or linear regions.

1:25

All right? So you have to become aware of that.

1:28

Equally important when you look at them is

1:31

to gauge the interosseous space.

1:33

'cause when we deal with significant problems

1:36

of the scapholunate ligament combined

1:38

with other ligament injuries, widening of

1:41

that interosseous space may occur.

1:44

Here's what they look like in the transverse plane.

1:47

So scapholunate, dorsal

1:50

and lar, same for the lunar triquetral.

1:54

So this is the strongest part right here.

1:57

This is the strongest part over in this region.

2:01

Now we're gonna add another structure

2:04

with a long complicated name

2:07

recently introduced in the literature

2:09

and considered by many to be a critical

2:12

stabilizer of the wrist.

2:14

It's known as the dorsal capsules scap illuminate septum.

2:19

It can be abbreviated DCSS. I'm gonna use that.

2:23

It shortens this talk about 10 minutes

2:25

if I can abbreviate it.

2:27

So DCSS, it's a critical connection.

2:31

It's in that green circle between the dorsal aspect

2:34

of the Scapa lunate interosseous ligament

2:37

and the dorsal capsule

2:39

and dorsal intercarpal uh, liga.

2:42

So you should be aware of that particular ligament.

2:46

And just to show you what it looks like here,

2:49

I show it in a drawing as gray.

2:51

This is the dorsal intercarpal ligament.

2:54

Here's what it looks like coming from the dorsal portion

2:57

of the scapholunate interosseous ligament connecting

3:00

to the dorsal intercarpal ligament.

3:03

It's in this region here.

3:04

Here's the dorsal intercarpal ligament.

3:07

Superficial to it, what are the patterns

3:11

of failure that we see with regard

3:16

to the scapholunate

3:18

and luno triquetral interosseous ligaments?

3:21

Well, there are two categories.

3:23

The first of these is traumatic.

3:26

So the traumatic tears, there are two types.

3:30

A peri lunate injury as you can see,

3:32

beginning on the radial aspect

3:34

through the interosseous ligament.

3:37

Then between the lunate and capitate,

3:40

and then descending on the ulnar aspect through the lunar

3:44

triquetral interosseous ligament.

3:47

That is a traumatic peri lunate injury.

3:49

We'll be talking about that toward the end.

3:51

When we talk about complex instability of the wrist,

3:56

this would be a reverse per lunate does just the opposite.

4:00

It begins on the ulnar side, extends around the lunate

4:04

and exits through the scapa lunate ligament.

4:08

Now far more common and far less clinically significant

4:13

or degenerative lesions of the scapholunate

4:16

or lunar triquetral interosseous ligaments.

4:20

They increase in frequency

4:21

and become quite frequent with advancing age.

4:25

And they, the tears of them become more severe

4:30

if you do a radiocarpal arthogram,

4:32

particularly in an older person.

4:34

Okay, and I'll talk more about this in the next lecture.

4:37

You will see in fact, communication

4:39

with the mid carpal compartment through one

4:42

or both of those spaces, those ligaments.

4:45

But this could be asymptomatic in an older person.

4:50

Now we can also classify

4:53

the failure patterns according to a morphology.

4:56

As I indicated before, uls

4:58

of injuries are particularly frequent.

5:00

Here's one involving the luno triquetral ligament at the

5:04

triquetral attachment.

5:06

Intrasubstance hair, however can occur here.

5:09

Again, lunar triquetral. And then failure in continuity.

5:14

The the ligaments may elongate.

5:16

Here is an elongated scap, lunate interosseous ligament.

5:22

Now there are some classification systems, particularly

5:25

for the dorsal aspect of the scap

5:28

lunate interosseous ligament.

5:30

I just wanted to show you this.

5:32

Type one is ACAP or devotion, be it soft tissue or bone.

5:36

It's fairly frequent. Okay?

5:40

A type two, again being soft tissue

5:42

or bone, far less frequent.

5:44

Shown here. The type three is a mid substance there.

5:48

And then the one last one, that kind of failure

5:51

with continuity.

5:52

Persistent is a type four.

5:55

You can see those on the boxes on your left taken from this

5:58

particular reference in the literature.

6:01

And by the way, here's a pearl for you.

6:04

When you wanna learn about the risks, you should simply

6:08

search for Garcia Elias.

6:10

His articles are spectacular.

6:14

Okay, just to show you a couple of examples.

6:17

Type one scaphoid bone avulsion.

6:21

So scapholunate interosseous ligament problem

6:24

with a bone avulsion Type two scap O lunate ligament problem

6:29

with a soft tissue avulsion and its lunate cy of attachment.

6:34

And just to show you another example here,

6:37

a partial tear shown by the white arrows

6:40

involving the lunate attachment, dorsal aspect mainly

6:45

of the lunar triquetral interosseous ligament.

6:49

Now what are a word about our arthrography?

6:52

We don't do a lot of Mr. Arthrography of the wrist.

6:57

Okay? But in fact, it is nice

7:00

because it's a joint

7:02

that you can get a needle into without having

7:05

fluoroscopic guidance.

7:07

It's very easy pick.

7:08

You flex the wrist

7:10

to get a needle into the radiocarpal compartment.

7:14

It probably has increased sensitivity for the

7:18

diagnosis of lesions of the TFCC.

7:21

I'll talk more about that the next talk

7:23

as well as the ligaments.

7:25

But if you do this, please use fluoroscopy

7:29

to look what happens to the contrast.

7:32

Because you see if it goes from the radiocarpal

7:35

to the mid carpal compartment, there are a bunch of pathways

7:41

with failure of certain ligaments, such

7:43

as the radio skate portion of the collateral ligament.

7:46

It may get in this way with a oid fracture, can go right

7:50

through the scaphoid SCA for lunate

7:52

and lunar triquetral ligaments can allow, um,

7:57

communication if they have communicating perforations.

8:00

And this one of my favorite around the ulnar aspect,

8:04

it occurs with a Palmer one

8:09

C lesion of the, of the triangular fibrocartilage complex.

8:13

And I'll talk about that in the second lecture.

8:17

So here, um,

8:18

and nice images sent to me by one of our

8:21

visiting scholars from Chile,

8:23

showing you two particular lesions.

8:26

Following a radiocarpal arthrogram, you can see the site

8:30

of tear of the lunar triquetral ligament.

8:33

This was mainly dorsal, it's labeled LT for you.

8:37

And you can see the defect involving the TFC likely

8:41

traumatic because of where it is located, okay, close

8:45

to its radial attachment.

8:49

Yeah. If you do not monitor the injection, you end up

8:53

with something like

8:54

This where all of the compartments are filled

8:58

with contrast agent

8:59

and you have absolutely no idea

9:03

how the contrast move from one compartment to the other.

9:08

Now, there are some possible advantages

9:10

of doing mid carpal arthrography rather than radiocarpal.

9:15

And before we MR came along, just standard arthrography,

9:19

we did a lot of mid carpal injections.

9:22

Here's a beautiful example of a mid carpal injection,

9:25

no contrast in the radiocarpal compartment,

9:27

but abnormal extension through this, uh,

9:31

lunar triquetral ligament.

9:33

So this is a partial tear of that ligament.