0:00

Let's move on to the last case I wanna show. Okay, let's start

0:04

again with the T1s, I always, again, like to look at the T1s. It

0:07

gives me like a nice gestalt of the case. I look at the

0:09

marrow to make sure it's nice and fatty and bright. Make sure there's

0:11

no hypointense fracture line. Make sure there's no hypointense or isointense

0:17

signal within the marrow to muscle, is it just a marrow proliferative or

0:20

marrow placing process. I already know that there's some degenerative changes.

0:23

I can see some probably some subchondral cyst, subchondral thinning along

0:27

the epithelial femur compartment here. It looks good overall,

0:31

you see the ACL, the PCL, so nothing really catching my eye that well

0:35

there. But if I turn to the sagittals, I'm starting here at the

0:42

lateral meniscus here. Okay. I'm seeing a little bit of signal here, that

0:53

I probably shouldn't see, you kind of have to window a little bit.

1:04

Sorry, I'm just gonna window this so you guys can see this better.

1:06

Okay. Okay. There's some vertical signal here and it's hard to see,

1:16

but there is some definitely linear vertical signal that's going to the

1:33

inferior surface, right? So it's all the periphery of this meniscus,

1:36

right? So this is actually a vertical longitudinal tear, let me see if

1:39

I can show it better on the coronals here. It's along the periphery

1:48

of the lateral meniscus. Kinda see it right here, right? There's a

1:57

vertical signal here, right? Kinda along the periphery. So I want to bring

2:01

on my last question, Ashley, which is question number seven,

2:06

which is vertical longitudinal meniscal tears are most commonly associated

2:08

with what? Are they associated with trauma, infection, degenerative joint

2:12

disease, or inflammation. What are, what do we see these most commonly associated

2:17

with? Okay, I'll let everyone finish up here.

2:22

Okay, so some of that, great. So we, this is excellent.

2:24

You guys have done phenomenal on these questions. So yeah, vertical longitudinal

2:28

tears tend to be related with trauma, right? Degenerative joint disease

2:31

usually results in like those horizontal cleavage tears, right? Like along

2:32

the, if you take a look along, they would kind of be running

2:38

parallel to the tibial plateau, kinda bisecting the meniscus in half.

2:42

Those are horizontal cleavage tear, those are associated with degenerative

2:44

joint disease. But vertical longitudinal tears are really associated with...

2:48

They're usually post traumatic in nature. Okay? So now do we care about

2:53

those tears, particularly vertical longitudinal tears along the periphery

2:57

of the meniscus? Probably not, right? Because remember the vertical... The

3:01

periphery of the meniscus is well vascularized, right? They're in the red

3:04

zone of the menisci, which means that they will likely heal on their

3:08

own. So if they're not displaced, we usually don't repair them surgically,

3:13

right? That's in contrast to free edge tears, like radial tears and things

3:16

like that where there's not a good vascular supply where we do repair

3:20

those or the orthopedic surgeon will do an arthroscopic repair of those

3:23

type of meniscal tissue, right? So that's a vertical longitudinal tear along

3:30

the posterior horn of the lateral meniscus. But let's go to the medial meniscus

3:34

and see if we see anything. So, I'm actually seeing something again.

3:37

So, first and foremost, I'm seeing sort of this oblique

3:41

under surface signal. Again, the windowing isn't optimal, but that's okay.

3:46

You can kinda see that there's some oblique under surface tearing here.

3:49

It's going on multiple slices and there's also this thing right here,

3:54

which is a parameniscal cyst. Okay? So this is a parameniscal cyst that's

3:59

associated with this meniscal tear. And the classic teaching is that if

4:02

you have a parameniscal cyst, it invariably means that there's gonna be

4:06

a meniscal tear, whether or not you see it or not,

4:08

right? So there could be an occult meniscal tear that you're not seeing.

4:12

But in this case, we actually see the tear. There's an oblique under

4:14

surface tear here, of the posterior horn of the medial meniscus. Now the

4:17

meniscus is still double the size of the anterior horn. The posterior horn

4:21

is still double the size, but this is just, that doesn't mean that

4:23

there's not a tear, that just means that there's not truncation of that

4:26

meniscus, right? Usually when there's truncation, that means that there's

4:29

a displaced tear, like a bucket handle tear or a flat tear or a flip tear,

4:33

right? But in this case, there's just an oblique under surface tear of

4:36

the posterior horn of the medial meniscus. Okay, let me come back. Let's

4:44

change here. Okay. Okay, good. So I also wanna look at some of

4:50

the other structures here since we're here. I wanna look at the coronal

4:54

T2 fat set. Okay? I just wanna kinda go over like some of

4:58

the search patterns, right? So we always wanna look medially, right? To

5:01

make sure the marrow edema is okay. And in this case,

5:03

the marrow edema is adequate, right? You wanna look at the articular cartilage.

5:07

Notice here that there is a little bit of cartilage fraying here,

5:10

maybe a little bit right along the medial femoral condyle articular cartilage,

5:14

you wanna look laterally at the marrow. The marrow overall looks good.

5:18

The articular cartilage looks nice and well preserved. Okay? You wanna,

5:23

on the Crohn's, if you wanna look at the medial collateral ligament that's

5:25

as about as good of a medial collateral ligament. You're gonna look,

5:28

you're gonna see inserting five to seven centimeters above the joint inserting

5:34

along the tibial five to seven centimeters below the joint, right?

5:36

Nice black dark signal. Okay. Laterally, again, you wanna look at the iliotibial

5:41

band, which is right here, ensure it's not a Gerdy's tubercle, nice and

5:44

black. Then you wanna look at the fibular collateral ligament that as good

5:49

of a fibular collateral ligament that you're gonna see going from the lateral

5:52

femoral condyle to the fibular head. This is the biceps femoris tendon,

5:55

looks good as well. And then the popliteus tendon, which is this structure

5:59

right here where my arrow is, you can see it inserting onto the popliteus

6:02

esophagus right here. Okay? So that's what this is. And then I think you

6:07

can kinda take a look at the crucial ligaments as well.

6:09

This is part of the PCL coming in here,

6:12

the ACL right here. Intermediate posterior lateral bundles inserting onto

6:16

the medial tibial spine. It looks nice and pristine, okay? That's just part

6:22

of the search pattern that we typically do.

6:30

And then if we come back here to the sagittal images,

6:32

we're gonna look at the extensor mechanism, nice view of the quadriceps

6:36

tendon, nice view of the patellar tendon, which overall are essentially

6:39

normal. So a little bit of edema Superolateral Hoffa's Fat Pad, but again,

6:42

that's a common finding, right? Some people ignore that, but some people

6:45

consider that part of the spectrum of patellar maltracking. There's really

6:48

no joint effusion here. If we go to the axial images, I think

6:53

this is the best place to look at the patellofemoral compartment of the

6:55

knee, as I was explaining earlier, right? So you can see, oh notice there's

6:59

some subchondral cystic change along with the patella that is the

7:05

lateral patella facet, right? There's also probably full thickness condyle

7:09

defects and fissuring of the lateral patella facet articular cartilage.

7:13

The medial patella facet looks much better. No marrow edema, no condyle

7:17

defect. The trochlea looks okay? This is the cartilage overall preserve,

7:22

right? The medial retinaculum looks good right here. The lateral retinaculum,

7:25

maybe like a partial or chronic sprain there, you can see some intermediate

7:29

signal there. And then you of course, always wanna look to see if there's

7:32

a Baker cyst, which is essentially right here between the medial gastrocnemius

7:37

and the semimembranosus tendons. You can see sort of beaked appearance of

7:41

fluid that's tracing right here. Okay? So then the, you always wanna look

7:46

at the muscles too, at the very end, right? So this is the

7:48

vastus medialis, vastus lateralis, sartorius, gracilis, semimembranosus

7:54

semitendinosus right here, right? And this is the biceps femoris muscle.

8:00

And these are the popliteus vasculature right here. This is part of the,

8:02

tibial nerve. And this is the common peroneal nerve right there,

8:07

right? Both of these approximately will become the sciatic nerve. So that's

8:10

kind of my search pattern for evaluating the knee, right? So again,

8:14

this was a vertical longitudinal tear along the periphery. They're usually

8:17

post traumatic in nature and they usually don't get repaired.

8:21

Those were the five cases I wanted to show today.

8:26

I'm happy to open up the floor for any questions that any of

8:31

the participants may have.