0:01

So let's look now at the more important lesions.

0:03

All right, starting with the one a central perforation,

0:07

typically this spates to a fall on an tressed hand

0:11

with a pronated forearm.

0:14

And that position leads to shortening of the radius.

0:17

So the ulnar relatively long compared to the radius,

0:21

produces an axial load that will in fact tear

0:26

that triangular fibrocartilage.

0:28

And the tear tends to be very, very close

0:32

to the radius.

0:33

So let's look at some examples.

0:35

I, I'm showing you here examples with, uh, arthrography

0:40

and you can appreciate, um, uh, I'm sorry this,

0:44

these are not okay, but uh, not arthrography.

0:47

You can see here the perforation.

0:49

This is a one A lesion pretty wide in the sagittal plane.

0:53

We can see it well, so this is close to,

0:57

but the key observation, that's a bit of the disc.

1:00

So it's not a away a point torn away from the

1:04

articular cartilage.

1:05

It's a defect in the disc close to the attachment

1:09

of the articular cartilage.

1:12

Here's the autogram.

1:13

Okay, so we've done a radiocarpal arthrogram here. Dorsally.

1:18

The dorsal part of the disc attaching

1:20

to cartilage is intact.

1:22

We move centrally

1:23

and we can see again a little bit of the disc.

1:26

So it's not a radio avulsion fairly war large gap.

1:30

Here's the rest of the TFC.

1:33

Okay, here's what

1:35

that would look like in the sagittal plane.

1:37

And then this is the volar radial mal ligament,

1:39

which is intact attaching to the radius, right, the bone,

1:44

not two articular cartilage.

1:48

Now we come to the most important lesion.

1:54

This, um, is the one B or proximal vols.

1:59

And as my diagram would indicate this could be soft tissue

2:02

or bone, but there's so many variations.

2:04

Look at this. I'm showing you drawings

2:07

of different variations of A one B lesion.

2:11

The styloid lamina torn,

2:16

the foveal lamina torn, both lamina torn here,

2:20

just a fracture here.

2:22

A fracture with distal involvement with proximal involvement

2:26

and with both involvement, both, uh, lamina involved.

2:30

So lots of different um, structures,

2:35

but you can sort it out if you look carefully.

2:39

The probable mechanism is said

2:41

to be a fall on an tress hand.

2:44

It leads to radial deviation

2:47

and hyperextension of the wrist.

2:49

And it puts tension particularly on those lar

2:54

ano carpal ligaments.

2:56

Some people think it's the ano capitate ligament

2:59

that is the most important

3:01

because uh, indeed they are putting tension

3:05

right on the TFC.

3:07

So you will get the proximal uls.

3:10

So let me show you some cases.

3:12

This is, and you can look at the diagrams to figure out

3:15

what the lesion is.

3:16

This is a lesion of the foveal attachment

3:20

and you can kind of see part of it here,

3:22

but there is a defect in it.

3:24

Note in fact that there is edema in the distal NAR

3:28

that can occur when you have an a problem with

3:31

that particular lamina.

3:34

All right? Note also that there is edema

3:39

around the distal ulnar, okay?

3:41

In this case, here's another one.

3:44

This is a lesion involving the styloid or distal lamina

3:49

and what can occur in this case.

3:52

Uh, here's the pre arthogram and orthographic images.

3:55

You can see here that the area of the abnormality can see

4:00

that here on the arthogram.

4:01

I would call your attention to leakage of the contrast agent

4:06

around kinda like this, around right around the YL

4:11

showing you you can have contrast medial to the distal

4:16

when you're dealing with lesions.

4:18

Type one B lesion. And another one.

4:21

This one is a styloid fracture.

4:24

This one near the base of the, of the thyroid with a tear

4:28

of the distal lamina.

4:30

Here's the fracture line note again, the edema.

4:34

And here is the lesion involving the uh, distal lamina.

4:38

Excuse me. All right.

4:42

This one is a fracture with uh, involvement

4:46

of the foveal lamina.

4:47

Here's the displaced fracture.

4:49

And here you can see the problem with the lamina.

4:53

I don't know why my voice is a little off

4:55

me have some water.

5:01

And I also wanted to point out

5:02

that you can have bone avulsions.

5:05

Now you see a bone fragment here

5:07

and we have a long list

5:08

of possibilities when these we see a fracture

5:11

or see a fragment there.

5:13

There is a ula, which is an accessory ossification.

5:16

Typically it's located here.

5:19

There may be a body within the pre recess

5:22

that should be somewhere over here.

5:25

There may be a body in the distal radi joint

5:28

that could look like this,

5:31

but this was a bone evulsion related

5:34

to the proximal lamina.

5:39

The main differential diagnosis is rheumatoid arthritis.

5:42

You can get synovitis within the pre recess

5:46

of the radiocarpal compartment.

5:48

Here's example, I showed this at a film panel of

5:53

the ISS

5:54

and it was read as a, uh, a problem

5:57

with the TFCC involving the foveal

6:01

and styloid lamina,

6:03

but rheumatoid arthritis can look like this.

6:07

Now, there is a new classification system

6:10

for the one B lesion that's been introduced by atse,

6:14

and he divides these into lesions that may be repairable

6:19

and those that often are not repairable

6:21

and may require reconstruction.

6:24

And you can see in the ones

6:25

that are repairable shown here in the red rectangle

6:30

that it isn't so much the number of laina that are involved,

6:34

but how much displaced they are.

6:37

If they're not displaced.

6:38

The TFC, not displaced, it's all right.

6:42

But if you get this much displacement

6:45

or disease in the distal radi, the joint,

6:47

typically they are not repairable.

6:51

Now I just wanted to show you a few examples of those

6:55

using arthrography.

6:57

So in theory, if you look at the top right,

7:00

if you do a radiocarpal arthrogram,

7:03

you will fill the presty recess,

7:05

but the contrast will not go beyond that

7:07

because you have in fact this styloid lamina.

7:13

And then if you do a distal radiar joint injection,

7:16

it should not go past the foveal lamina.

7:20

So let's look at this example.

7:22

This is an injection both into the radiocarpal

7:25

and distal radiar joints.

7:27

We're gonna see some abnormal extension right here owing

7:30

to the lesion of the thyroid lamina.

7:34

There is the area of involvement,

7:36

so the contrast can get all the way over

7:38

to the foveal lamina,

7:40

and this is fluid that was injected directly into the

7:43

distal radial and the joint.

7:44

Let's look at this example where both lamina are torn.

7:48

We did a radiocarpal arthrogram

7:50

and you can see now that the contrast can get through though

7:54

that defect and fill the distal radial in the joint.

7:58

So arthrography can be helpful. We don't use it that often.