0:00

Alright, we're ready to move on now

0:02

and talk about the ligaments of the wrist.

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To simplify this, we will define intrinsic ligaments

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and extrinsic ligaments.

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Intrinsic ligaments extend between adjacent carpal bones.

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They're short ligaments.

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They attach mainly the cartilage

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and they often fail through avulsion rather than

0:28

mid substance tears.

0:30

The extrinsic ligaments are said to connect the forearm

0:33

to the carpal bone, so the radius

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or ulnar typically to the proximal carpal row,

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but also sometimes to the distal carpal row.

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These are long ligaments that attach mainly to bone,

0:46

not to cartilage.

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They fail through mid substance tears rather than

0:51

evulsion injuries.

0:52

Now those are the general rules, the difference intrinsic

0:57

and extrinsic.

0:58

And you'll note there's no definition for the ligaments

1:02

that go from the distal carpal row to the metacarpal basis.

1:06

I will assume we could label them extrinsic,

1:09

but you won't find that definition in the literature.

1:13

So now what we need to do is

1:15

to introduce these ligaments starting vly

1:19

deep to superficial.

1:21

And once again, I apologize

1:23

for the beginners are gonna find a lot of terms now

1:26

that they are not familiar with.

1:29

Let's start by talking about the intrinsic deep layer.

1:33

And there are ligaments here,

1:35

including the scapholunate interosseous ligament.

1:39

Okay? We can see the lunar triquetral interosseous ligament,

1:44

the distal roll interosseous ligaments,

1:48

and then intercarpal ligaments.

1:50

You can see one between the scaphoid and capitate.

1:53

Another between the triquetrum, hamate and capitate.

1:57

These are gonna become very important ligaments later on.

2:02

The triquetral hamate capitate

2:04

and the scavo capitate ligaments bridge,

2:07

the mid carpal joint.

2:09

We're gonna talk about mid carpal instability later on.

2:12

These ligaments have to be involved together.

2:15

They are called the arcuate ligament of the wrist.

2:20

The next layer are extrinsic ligaments,

2:23

and this is the deeper extrinsic ligaments

2:26

here shown in orange are the four major ones.

2:30

The radio SC or lunate.

2:31

I put a little asterisk next

2:33

to it more about that in a moment.

2:35

The short radio lunate, you're gonna learn more about

2:38

that when we have these lunate dislocations.

2:42

And then two of the three, oh no carpal ligaments,

2:46

the onno lunate and the onno triquetral ligaments.

2:49

And that's going from radial to as I introduced.

2:54

Now the indicates that the radios lunate ligament may not be

2:59

and probably is not a true ligament.

3:02

It is a conduit for nerves and vessels

3:05

and has very little ligamentous characteristic.

3:10

The third layer that we have to deal

3:11

with is the superficial portion of the extrinsic ligaments.

3:16

Okay, I show those in a purple color.

3:19

We're gonna start radially and go ally.

3:22

The radio scaphoid ligament is shown here.

3:25

It's a portion of the radial collateral ligament.

3:28

It's the most important portion of that ligament.

3:32

The next is a long ligament, the radica capitate ligament.

3:37

That's gonna be important. Uh, ligament.

3:40

It's part of the deltoid ligament.

3:42

There's a long radio lunate ligament.

3:45

It has another name I'll tell you about that in a moment.

3:48

And then the third, oh no carpal ligament is a long one.

3:52

This is the, oh no capitate ligament.

3:55

So those are the superficial layer

3:58

of the extrinsic ligaments.

4:01

Now the long radio lunate ligament is sometimes designated

4:04

the radio luno triquetral ligament

4:07

because it goes on as either a single

4:10

or two bands of tissue to attach to the trium.

4:17

And then miscellaneous extracapsular

4:20

ligaments three in number.

4:22

You can see here a piso ate ligament,

4:27

piso metacarpal ligament

4:29

and the transverse carpal ligament intimate

4:32

with a carpal tunnel of the wrist.

4:35

So that's the important anatomy.

4:38

Now, just to give you an idea with these beautiful drawings,

4:41

okay, from from Michael Stadnik here,

4:44

the deltoid ligament shown on the left is the radio scap,

4:49

capitate and ul, no capitate ligaments.

4:53

They bridge from the radius

4:54

and ul nut to the distal carpal row.

4:58

I show you portions of them in the mr on your left,

5:02

we don't see the ul no capitate ligament very well.

5:06

The arcuate ligament, which is a deeper structure,

5:10

is the one I introduced earlier, the scavo capitate

5:13

and the triquetral hamal capitate ligaments

5:17

bridging the mid carpal joint.

5:19

And you can see the image at the top right showing you parts

5:22

of those ligaments.

5:25

Now if you look at those ligaments superficial

5:28

and deep, you can see an area on the vola

5:31

aspect of the wrist.

5:33

That is the void of ligament to support.

5:36

This is called the space of Ria.

5:39

I am sure you all learned about it in medical school.

5:42

It's a weak triangular area

5:44

because there are no ligaments there.

5:46

And the typical triangle

5:48

that is illustrated is the one I show you here.

5:51

We're gonna change its shape in in a moment or two.

5:55

Well, it becomes important because

5:57

You could imagine that this is kind

6:00

of like a transparent aspect of the capsule

6:03

and right beneath it,

6:04

or deep to it, of course is the lunate.

6:08

So you might imagine with lunate dislocations,

6:11

the lunate could extend

6:12

through this triangular space rotate.

6:16

And here's what it would look like if you had a lar

6:19

lunate dislocation.

6:22

This is exactly the appearance,

6:24

and I'll get back to this toward the end of this lecture.

6:28

Now I wanna show you what the real shape is, okay?

6:32

Of the space of parer.

6:34

This is the triangle

6:35

and the reason that becomes important,

6:38

it extends more radial than most books suggest.

6:42

It includes in fact, showing you a bit of the skateboard.

6:45

So it's not surprising

6:47

that we get trans skateboard per lunate fractured

6:51

dislocations where both the lunate

6:53

and the proximal pole of the scaphoid make their way

6:57

through this elongated triangle of the space of parer.

7:03

Now, if we look at those lar ligaments using Mr. Or Mr.

7:07

Arthrography, and again,

7:09

I would indicate in my lecture a lot of Mr.

7:12

Mr. Arthrograms will be shown.

7:15

I'm showing you here with the yellow brackets,

7:17

the radio sca capitate ligament in all of the images

7:21

and with the purple brackets,

7:22

the radio luno triquetral ligaments.

7:25

So you can see them.

7:27

But there, um, the width of them can vary.

7:31

One of the important aspects there is a space located

7:35

between these two ligaments, probably best shown right here,

7:39

shown in the specimen right here.

7:41

That looks like a tear of the volar aspect

7:45

of the scapholunate interosseous ligament.

7:48

It is a pseudo tear, and you should remember that

7:52

because it creates diagnostic error.

7:55

You'll misinterpret it as a tear.

7:58

Now let's go to the sagittal plane first at the level

8:00

of the scavo, Mr.

8:03

Arthrography. This was multi compartment arthrograms.

8:06

This then is the radio scape,

8:08

O capitate ligament heading toward the skateboard.

8:11

Here is the takeoff of the radio luno triquetral ligament.

8:15

You can see that beautifully in the corresponding section.

8:19

These are taken from some of the articles done

8:22

by our visiting scholars, a lot

8:24

of them related to the wrist.

8:26

And then we move over more medially to the lunate.

8:30

And now we can see the attachment of the radio scap

8:34

or capitate ligament to the volar surface of the capitate.

8:38

And we can see the radio lunate, radio lunar treat,

8:42

triquetral ligament.

8:44

Now attaching to the lunate.