0:00

I'd like to talk about some unique situations

0:04

and some kind of a unique, quirky kind of guy.

0:08

The first unique situation, with regard to

0:11

parameters, is the relationship of the radius and

0:15

ulna and how congruent they are to each other.

0:19

Pretend my two fingers on each hand represent

0:23

each hand, and one represents the radius,

0:27

the middle finger, and the shorter finger,

0:30

my index finger, represents the ulna.

0:33

Now, when you pronate or supinate, there should be

0:38

a congruent rotational relationship between the two.

0:43

Sometimes what can happen is the

0:45

ulna can start to float dorsally.

0:48

Now fortunately, it only does it usually on one side.

0:52

So the optimal thing is to scan a patient with either

0:56

CT or MRI in a steep pronated and supinated view.

1:02

And compare how dorsal the ulna is to the

1:06

radius in the short axis axial projection.

1:12

This is an extremely important maneuver because

1:15

it's a common cause of wrist pain, namely radial

1:20

ulnar instability, usually only in one wrist.

1:23

So you're looking for something as simple as symmetry.

1:28

Then I've got another maneuver for you.

1:31

I hardly ever put intra

1:34

articular contrast in the wrist.

1:36

There is no need.

1:37

As we'll see later on, the direct and the

1:40

indirect signs of scapholunate and lunato

1:43

triquetral insufficiency are more than enough.

1:49

Sometimes, you can augment your diagnosis

1:52

without an arthrographic injection by simply

1:55

looking at the wrist in the neutral position.

1:58

And then imaging it coronally in the steep radial,

2:03

sorry, steep ulnar deviation position and steep radial

2:07

deviation position to see if the intrinsic proximal row

2:11

ligaments separate in either radial or ulnar deviation.

2:17

You'll have to call for these views in unique

2:20

situations or train your technologist to

2:24

do so When the situation is appropriate.

2:28

Now let me do a little bit of drawing.

2:31

I want to talk about a controversial

2:34

subject that hand surgeons and radiologists

2:37

go back and forth on quite a bit.

2:39

And that is the concept of variance.

2:42

So I'm going to do my best to draw you an

2:44

ulnar with an ulnar styloid and a radius.

2:50

And here's our radial ulnar articulation.

2:52

There's our scaphoid fossa just to get oriented.

2:57

Now surgeons like to talk about variance on x ray.

3:01

The relationship proximal to

3:04

distal of the ulna to the radius.

3:07

In certain positions, like a clenched fist view

3:12

or steep pronation, the ulna may jut distally.

3:17

and may abut and encroach on the lunate.

3:21

Now we're not using x ray, we're using

3:22

MRI, often in a neutral position, sometimes

3:26

pronated, sometimes supinated, so there's

3:30

a tremendous amount of variability in

3:32

how the technologist positions the wrist.

3:36

In general, I use about 8 millimeters of

3:42

disparity between the marginal edge of the

3:45

ulna and the marginal edge of the radius.

3:47

So if it's short by 8 millimeters, or if

3:49

it's too long by 8 millimeters, I suggest

3:53

that there's ulnar variance posture.

3:57

I put that posture word in there so

3:59

the hand surgeons won't yell at me.

4:02

In other words, I don't want to use their

4:04

term, ulnar variance, which is an x ray term.

4:06

I use the posture adjective to get out of jail free

4:12

and make sure they know that there's a tendency for

4:14

the ulna to be a little too long or a little too short.

4:20

Sometimes, I'll even do a clenched fist view.

4:25

The most valuable aspect of determining

4:29

whether variance posture contributes

4:32

to disease are the secondary signs.

4:35

When the ulna is too short, you'll frequent.

4:38

You'll frequently see swelling over here

4:43

at the peripheral attachments of the TFCC.

4:49

If the ulna is too long, positive variance

4:55

posture, it'll abut against the lunate.

4:59

And it'll produce erosions in the lunate,

5:02

and you'll also see some adjacent areas of

5:05

chondromalacia around the lunate and around the ulna.

5:09

So you'll see some chondromalacia right there,

5:11

and you'll see some chondromalacia right there.

5:13

You may have a little bit of fluid, a little bit of

5:16

swelling, and it's these indirect signs that tell

5:19

you when posture is really relevant to the diagnosis.

5:24

My final, unique, quirky point.

5:28

Contrast.

5:30

I rarely, to uncommonly, use contrast in the wrist.

5:34

If I have some weird looking mass that I can't

5:37

characterize, in other words, looks like a

5:39

ganglion, smells like a ganglion, feels like

5:42

a ganglion, but it's in a funny spot with

5:44

some features of atypicality, it's funny.

5:47

I'm going to inject it, but if it's in

5:50

the typical position along the scapho

5:53

lunate capsule with the proper signal and

5:56

smooth and round, I'm not injecting it.

6:00

Finally, arthrographic injection.

6:03

I use arthrographic injection almost every day.

6:07

0 percent of the time to diagnose

6:10

scapho lunate ligament injuries.

6:13

I'll use it about 10 20 percent of the time to diagnose

6:17

lunato triquetral ligament injuries since this ligament

6:21

is smaller and sometimes more difficult to identify.

6:27

But that is really an exception.

6:29

So I don't commonly give injections, IV

6:34

for masses, and I don't commonly inject.

6:37

Intra articulately, with an arthrogram,

6:40

for the wrist, unless I'm forced to.

6:43

My next point gets its own discussion.

6:47

Proper angles for assessment of the scaphoid bone.