0:00

There are a number of provocative tests

0:02

that have been used by orthopedic surgeons

0:05

to determine whether or not there is a labral abnormality.

0:10

Most famous one of these is Faber a f test,

0:15

flexion abduction and external rotation.

0:19

This is the position with the hip.

0:22

You can see bent at the knee here, that foot on top

0:27

of the opposite limb.

0:28

You push down, you measure the distance between the knee

0:32

and the top of the table.

0:34

And if you have labral pathology

0:36

and end up with a positive test, that distances increase.

0:40

So this is said to be a good provocative test,

0:45

but it's not specific for lab pathology.

0:50

Now, with regard to

0:52

what are the MR imaging findings involving the labrum

0:56

and asymptomatic persons?

0:57

Many early articles,

0:59

and I've cited some here, have indicated

1:02

that there are frequent alterations in the shape

1:05

or signal intensity within the labrum,

1:07

even in asymptomatic persons triangular shape, yes,

1:12

but can be rounded, it can be irregular,

1:14

and even in a infrequently it can be absent.

1:19

And with regard to signal intensity,

1:21

typically gray signal either gular

1:24

or linear could be seen in asymptomatic persons within the

1:29

labrum, often contacting the surface of the labrum,

1:33

creating diagnostic problems.

1:35

These related to mucinous

1:37

and oid change with without labral ification.

1:42

When we talk about labral tearing, the dominant location is

1:46

above the equator and particularly superior anterosuperior

1:51

and anterior portions of a labrum

1:54

that are vulnerable to tearing.

1:56

Some people suggest it relates to a poorer vascular supply,

2:00

a weaker attachment of the labrum to the cartilage and bone.

2:05

Okay? Or perhaps these areas undergo greater stress.

2:10

It's of interest that it's been pointed out that in, uh,

2:14

Asia, particularly in Japan, but elsewhere, that posterior

2:18

and post row superior labral tears may be more common,

2:21

may be related to more sitting

2:23

or squatting when compared to other areas of the world,

2:29

we come along again as the imagers

2:31

and the question arises, how

2:34

good are we at detecting label abnormalities

2:37

and specifically labeled errors?

2:39

So I put up some figures taken from a recent article on the

2:42

subject indicating that with Mr Imaging,

2:45

particularly if you go to high field strength imaging,

2:49

we do pretty well with sensitivity

2:52

and specificity of picking up labral pairs.

2:56

When, and this is an example just of, uh,

2:59

Standard Mr. R imaging

3:00

showing you the labral tear. When we go to Mr.

3:05

Arthrography, perhaps the sensitivity increases a bit.

3:10

The specificity doesn't really change very much.

3:14

So I think, uh, that in most places in the United States

3:19

and around the world, people are turning away from Mr.

3:22

Arthrography as a, a technique necessary

3:27

to assess the labrum.

3:29

That if you're dealing with good image quality with a 1.5

3:32

or certainly a three Tesla unit, you probably do not need

3:37

arthrography like this in, in order

3:39

to detect labral pathology.

3:42

Now, there is an interesting, uh, thing that you might do,

3:47

and this has been emphasized mainly in the European

3:50

literature, but you can apply traction to the leg, right,

3:54

utilizing sandbags that are compatible with the magnet.

3:58

And if you apply traction to the leg, particularly

4:02

if there is native fluid in the hip joint,

4:06

or if you've done an arthrogram,

4:08

you can draw the femoral head away from the acetabulum.

4:13

And I think this is really state

4:15

of the art imaging right now,

4:17

that when we do arthrography without leg traction,

4:21

we often get a lot of contrast around the labrum,

4:24

but we don't see the cartilage well.

4:26

And, and, and so when you go ahead

4:28

and put traction on the hip,

4:31

and these, this images sent to me by Nicholas Tuman, one

4:34

of our previous, um, uh, scholars from, uh, Switzerland,

4:39

you can see here a little bit harder to judge the cartilage.

4:42

You pull the femoral head away with leg traction,

4:46

and here you can see beautifully not only the labral

4:49

pathology, but the delamination that's occurring,

4:52

especially in the acetabular articular cartilage.

4:56

So I think this is a technique

4:58

that can be very, very useful.

5:00

Unfortunately, in our practice,

5:02

we are not using it currently.

5:05

Another technique that has been used,

5:07

and I noticed there was a, uh, comment about this, uh, that,

5:11

that people are interested in radial imaging.

5:13

We don't do a lot of radial imaging,

5:16

but indeed, when compared to other imaging planes for here,

5:20

for example, sagittal admitting take, these are old images,

5:24

but radial imaging might pro, uh, provide an advantage.

5:29

And I came across this image taken from a recent article

5:33

in the Journal of Magnetic Resonance Imaging

5:36

that compared using an orange analogy,

5:40

what standard imaging looks like compared to radial imaging

5:44

of the, uh, femoral head.

5:46

Because if you're using standard MR imaging of the hip

5:50

with orthogonal planes, you have different amounts

5:54

of articular cartilage and labrum

5:57

Shown here in every section.

5:59

If you use radial imaging, you end up, typically,

6:04

if you program tho those along the curvature

6:07

of the femoral head and ace tum, you have equal amounts

6:11

of labrum and articular cartilage in every

6:15

one of the images.

6:17

But in our practice,

6:18

I don't believe we're using radial imaging very much.