0:00

Okay, we'll finish up, uh, in the last 10 minutes

0:04

or so by talking a bit about meniscal surgery to operate

0:09

or not to operate.

0:10

Tears that are suitable

0:12

for repair are peripheral tears close to the joint capsule.

0:15

Typically, those that are longitudinal vertical in

0:21

direction, tears that are suitable

0:23

for partial menisectomy are those in the avascular zone

0:27

and complex, often multi-directional tears, tears suitable

0:32

for complex or complete, I'm sorry, meniscectomy.

0:35

Severe or extensive meniscal tears

0:38

and tears that might be left alone.

0:41

Are those in the periphery, those that are stable,

0:45

some short radial tears

0:47

and particularly degenerative tears when there's already

0:50

evidence of compartmental osteoarthritis.

0:53

Now I just wanted to show you

0:54

what partial menisectomy can look like.

0:58

I took these pictures from the literature.

1:00

This is a par B tear shown in a image.

1:04

B shows the tear is grabbed with a basket.

1:07

Forceps image C shows debridement of the region in the,

1:12

in the region of the tear.

1:14

And you can see in image D what you wanna end up with

1:19

if that is a very smooth, although truncated in a margin.

1:23

So this is what the orthopedic surgeon wants.

1:26

What we often get is something like this,

1:29

not a very good surgical result.

1:31

And it's because of that

1:33

and what might be a post-surgical irregular border

1:37

that when we deal with the rules of engagement, try

1:41

to interpret whether or not there is a retail.

1:44

We run into difficulty. The usual rules do not work here.

1:48

You're looking at example of a partial mastectomy,

1:52

and if we image it first in the coronal plane,

1:55

kinda looks like a tear.

1:56

Perhaps that signal violating the meniscal surface.

2:00

We image it in the sagittal plane.

2:02

And again, altered signal. We run into difficulty.

2:06

Now, one of the things that we can look for, which is fairly

2:10

reliable, is that when there is an associated joint

2:13

diffusion and that joint fluid passes into

2:18

the meniscal tissue, that's strong evidence.

2:21

Probably not certain evidence that you're dealing

2:24

with a meniscal gap and likely with a meniscal tear.

2:28

And it's because of that, that there may be a role for Mr.

2:33

Arthrography, particularly direct Mr.

2:36

Arthrography, where we are injecting contrast

2:40

material into the joint.

2:42

So we look for the contrast agent to enter the meniscus

2:45

as a sign of a meniscal tear.

2:49

Doesn't always work,

2:50

but that is the general thing we look for.

2:53

So here are two images. This image, no meniscal re tear.

2:57

Here's an autogram with contrast running into the meniscus.

3:01

A small meniscal tear here, Mr.

3:05

Arthrography meniscal tear contrast running in.

3:10

This is more accurate when a greater amount

3:13

of the meniscal tissue has been removed.

3:18

Here's another example, Mr.

3:20

Arthrography partial menisectomy meniscal tear.

3:25

And in this example, Mr.

3:27

Arthrography, no contrast agent passing into the meniscus.

3:31

This is no meniscal tear.

3:34

Another thing that you may see when dealing with, uh,

3:38

patients who've had partial meniscectomies

3:41

or radial tears, one or more,

3:44

and that relates to hoop stress,

3:46

which is now attacking a meniscus that is not as wide

3:50

as it normally should be.

3:52

Here's an example of

3:54

what a radial meniscal retailer would look like.

3:58

So when we look at the reported accuracy

4:01

and analysis of the meniscus following surgery,

4:04

whether it's repair

4:05

or menisectomy, here are some figures

4:08

that I got from a rather recent article

4:11

and you can see that with direct Mr.

4:14

Arthrography. Okay?

4:16

I think you could argue that there is perhaps an advantage,

4:20

something that you might want to consider indirect.

4:23

Mr. Arthrography, where you use intravenous gadolinium

4:27

and delay your imaging also can be useful, right?

4:31

This is a positive direct Mr.

4:34

Autogram with a small tear, vertical tear at the periphery

4:39

of the meniscus.

4:40

So the last few slides,

4:42

just a couple other things to mention.

4:44

What about finding a para meniscal cyst in a

4:47

postoperative knee?

4:49

Now this may not indicate a meniscal re tear

4:53

for preoperative meniscal cyst may persist following

4:57

surgery, but it can indicate a meniscal repair,

5:01

as in this particular case with Mr.

5:04

Arthrography contrast filling the torn meniscus as well

5:08

as filling the para meniscal cyst

5:14

causes of pain following meniscal surgery.

5:17

I show you a list of some of the causes.

5:19

Here's an example of a fairly extensive partial menisectomy

5:24

with a full thickness chondral defect

5:28

contrast passing in it, alright, no meniscal retail,

5:33

but a large cartilage abnormality.

5:36

And of course, the other thing you wanna look for

5:39

following partial meniscectomies

5:41

or total meniscectomies abnormal stress placed upon the bone

5:46

insufficiency fractures.

5:47

I talked a bit about this yesterday.

5:50

So what I've done in my allotted period of time, hopefully,

5:54

is a fairly complete discussion of

5:57

The knee meniscus.

5:58

We've reviewed meniscal structure, we

6:01

emphasized the collagen framework.

6:04

We talked about classic patterns of meniscal failure

6:08

based on an understanding of its structure.

6:11

And then we reviewed some

6:13

of the diagnostic pitfalls involved in the interpretation

6:16

of meniscal failure, and finally addressing the

6:19

postoperative, uh, meniscus.