0:00

So the first case, an 11 or 12 year old with medial knee pain,

0:06

no known injury. So here, uh,

0:09

I'll try a little bit different today and I'll, I'll hang up, uh, how I usually,

0:14

um, uh, set up my viewing protocols. Um, but typically,

0:19

and I was asked this by, by a, a student, um, and, um,

0:24

one of your classmates. So, so the way I like to hang it is, is just, uh,

0:29

coronals tip for knees, at least coronals on top. Sagal is on the bottom,

0:33

and then axials somewhere on the side. Um, I,

0:37

I obviously because of, uh, zoom's, uh,

0:40

limitations from Zoom to have at least one t one weighted sequence in one plane

0:44

just to, uh, uh, best evaluate the marrow. Um, and then,

0:49

and then I'll have, uh, a longitudinal, either two sagittals that,

0:53

or two Coronas, and then, and then one sagal, cornal, uh, uh, what have you.

0:58

And then obviously the axial. So dealing with this first case, uh,

1:02

just going right to the, uh,

1:05

the salient findings we see here that we have, uh, uh,

1:10

osteochondral, uh, irregularity or abnormality at the central,

1:15

sort of posterior aspect of the, uh, medial femoral condyle right here,

1:20

compatible with, uh, or in the spectrum of osteo meningitis. Dessicans,

1:25

okay. Um, thought to be an idiopathic, uh, uh,

1:29

cause some people say could be from, uh, trauma or, or, or, um,

1:34

activities, what have you. But typically gonna be in a,

1:37

in an adolescent or a young patient, as in our index case.

1:42

And what we see here are, uh, the, uh,

1:46

going from, um,

1:48

the articular surface or the cartilage we see here that, uh,

1:53

the cartilage is looking, uh, pretty good. Okay? Um,

1:57

next I'll,

1:58

I'll look at the subc chondral bone plate for any cracks or disruptions.

2:03

Okay? But, uh, most importantly, what you wanna look at is, uh,

2:08

the, um,

2:09

and depending on who you read or what terms you use for your practice, uh,

2:14

I've, I've ca I've heard the, this, uh, entity,

2:19

um, sometimes I get asked how to, how to, how what,

2:22

what source of terminology I use to describe OCDs or osteo neuritis test cans.

2:27

So some people will call this the lesion itself. That is the, um,

2:32

the, uh, the stable or unstable fragment.

2:36

I've also heard it called, uh, progeny. Okay?

2:40

And then deeper to that, uh, people will use, uh, the terms, you know,

2:44

fluid or cleft, what have you, or even lesion bed. And then,

2:49

and then, uh, the under, underneath, all of that. Um,

2:54

you know, people will, will some,

2:56

I've heard some authors or some people call it the, uh, the parent bone. Okay?

3:01

Um, so the big, the big thing with this case is, is to determine, um,

3:06

uh, stability or instability, okay? Um,

3:10

and depending on who you read, uh, but, but, uh, for those that are interested,

3:15

uh, you wanna look up, uh, dis met Deme, DE, uh,

3:19

DE capital SMET. He's, he's probably done, he's, uh,

3:24

done the most work on. And, uh, o out of Wisconsin, uh,

3:29

on o osteochondritis, deic hands in various locations, probably most,

3:33

mostly involving the, um, the knee and tailless. Okay?

3:38

But basically what you're gonna be looking for is disruption in between,

3:43

um,

3:44

the progeny or actual lesion and the parent bone or lesion bed.

3:49

And what do I mean by that? Basically,

3:51

you want to see disruption of the cartilage, okay?

3:54

Disruption of the subc choral bone plate fluid signal, okay?

3:59

Fluid signal,

4:00

undermining that lesion or progeny and interposed between

4:05

that and the parent bone, creating what some people have, uh,

4:09

liken to the Oreo cookie sign, okay? And be,

4:14

and it's called the Oreo cookie sign. Because typically, um, these, uh,

4:19

lesions, uh, are going to be,

4:21

or the bone actually is going to be typically, uh,

4:24

dark on your MR sequences surrounding the, uh,

4:29

the cream of the Oreo cookie, or that is the fluid centrally. Okay?

4:33

So let me blow this up. Okay. So just to highlight some of the, some of the,

4:38

uh, potential, uh, unstable features. Oh, and sorry,

4:42

the other criteria are, are going to be, besides the fluid you want to see, uh,

4:48

sclerosis at the lesion bed or the, the parent bone, okay?

4:53

Or basically dark, uh, dark T one and T two signal, or,

4:58

uh, dis met. And,

5:00

and others have also mentioned that you want to see multiple cysts, okay?

5:05

Or a single cyst that measures about five millimeters or more,

5:10

okay? When you, the more obviously features you have in such a case,

5:15

okay? Um, then you want to call, uh,

5:18

instability or at least suggest it. Okay? Why is that important?

5:22

Because if it's unstable, then it's gonna flip off eventually, uh, and,

5:27

um, you know,

5:29

displace and then obviously lead to early osteoporosis in these patients.

5:32

And that's what, that's the whole name, name of the game.

5:35

We're trying to prevent that early osteoporosis. Okay? Um,

5:40

so in this case, uh, you can see, we can see here that there is a cyst.

5:44

There's maybe, there's, there's, uh, arguably some T two, uh,

5:48

hypo intensity at the lesion bed or the parent bone, okay?

5:52

And then we have an incomplete fluid signal interposed between

5:57

the progeny and parent bone or lesion bed. Okay? And then obviously the,

6:02

the lesion or the progeny itself, the, the, um,

6:07

the epi seal cartilage or the overlying cartilage does look intact. So,

6:12

um, I would read this and, and the,

6:16

I think the master grading also said sheet says that this, uh,

6:20

should be read as potentially unstable or perhaps partially unstable.

6:25

And the importance of this is you wanna, uh,

6:27

at least monitor it closely and maybe even go in and, and, uh, and fix this,

6:31

or at least, uh, go in there with maybe a, a,

6:35

a drill and stimulate some healing. Okay?

6:38

Some authors will also recommend that, uh, you mention the, um,

6:44

how the fis, the, the nearby feys look, whether they're closed or open.

6:49

Okay. And why is that important? Because younger patients,

6:54

uh, depending on who you read, okay, um, uh,

7:00

13, um,

7:02

15 or younger thir 13 to 15 years old or younger,

7:06

when p when p patients still have open fes, okay?

7:11

MR is typically gonna be more sensitive. Why is that?

7:14

Because oftentimes what happens is in these younger patients, okay,

7:19

uh, the overlying, uh, epi steel cartilage looks intact.

7:24

So basically,

7:26

when the arthroscopy goes in and looks at the cartilage

7:31

or looks for this OCD, because the, the,

7:34

these patients that are younger with intact cartilage,

7:38

and typically too, you have to remember, um,

7:41

there's an inverse relationship between patient age and the thickness of this

7:46

epi, epi fial cartilage. So, as patients, as we all age,

7:49

we know that our cartilage thins out whatever, for whatever reasons, you know,

7:53

we lose lubricants, you know, the water and the, between the glyco,

7:58

amino glycans, the Gs, and what have you, me,

8:02

mucopolysaccharides this cartilage thins as we age. So as the, the,

8:07

the scope is, uh, placed in the knee, the,

8:11

the arthroscopist may,

8:13

may not see this potentially unstable lesion until

8:18

later when things, uh, when things thin out,

8:20

and they start to see cracks within the cartilage,

8:23

and thereby they can see underneath to the lesion itself.

8:28

So in younger patients, typically, you know, 13,

8:31

depending on who you read or younger,

8:34

you may want to mention that the feisty is still open. And you know, this, um,

8:38

lesion can be concealed, per se, okay? Under arthroscopy.

8:43

And it's actually been out in the literature literature too. Okay? Uh,

8:48

patients, uh, there's an article out in the literature, um, you know,

8:52

when patients are above 17, that's when we, uh, that's when art,

8:56

the arthroscopy will tend to be, uh, see these lesions better,

9:01

okay? And thereby, and, uh, thereby that'll affect or,

9:05

or be reflected also in the sensitivity or specificity. Specificity.

9:10

The specificity as patients get older for our mr uh,

9:15

imaging diagnoses will increase, okay? Because, uh,

9:19

you know, most articles will use, uh,

9:22

arthroscopy as the gold standard. But if you really think about it, MRI,

9:28

uh, will be,

9:29

will be able to diagnoses earlier in, um,

9:34

in younger patients where the FI cs are still open and the epi cartilage

9:39

is still thick. So the, uh, so in the younger patients, the,

9:43

the specificity is actually gonna be much lower. And some, in, in some articles,

9:47

it d it, uh,

9:48

states that the specificity in these young patients can be as low as 10%. Okay?

9:53

So this is an OCD lesion or osteo testic cans. The differential, uh,

9:58

to think about is gonna be, you know, uh,

10:00

distal femoral irregularity and the way to parse that out, um,

10:04

the sides imaging the patient over time. Um, you're typically not gonna see,

10:09

um, you know, the cystic change, edema, fluid cleft,

10:14

what have you in the, uh, normal ossification center development, uh,

10:19

which is the differential in this case. So with that, um, uh,

10:24

that is case number one, OCD. Any questions on this first case?

10:29

There was also a question on what is meant by shoulder and un shoulder

10:34

or contained and uncontained. So basically, um, I,

10:38

I believe that is extrapolated from, um, ankle arthroscopy.

10:43

Okay? And basically what the orthopedist means, uh,

10:47

by that to my understanding, is that when you have these, uh,

10:52

osteochondral injuries, lesions, OCDs,

10:56

whatever term you use, okay,

10:58

when it involves the curve or a curve of, uh,

11:02

of an articular surface, it can be more difficult for our, uh,

11:07

surgeons to treat. So that's, that's what's meant, what,

11:11

that's what's meant by shoulder, non shoulder or contain uncontained,

11:16

uh, OCDs to address your first question, yeah, for osteo tendinitis, tecans,

11:20

there's many classification systems. You know, uh, off the top of my head, if I,

11:25

if I remember, remember correctly,

11:27

I think there's like a hefty H-E-F-T-I that you can look up. There's also,

11:32

um, there's an author,

11:33

there's a group that it begins with the c char oscopy,

11:38

oscopy or something like that, maybe, I apologize. Um, but I can get that to,

11:42

to you all later or whoever's interested. But, but yeah, you can,

11:47

you can use classification systems. But an important thing is for me,

11:51

I just keep an open dialogue

11:52

With, uh, open communication line of communication with,

11:55

with my orthopedic surgeons. Um, they have my, uh, direct,

12:00

uh, cell number. So I basically read to,

12:05

to the clinician, um, if they use, if,

12:08

if I run into a classification, if I run into a clinician,

12:12

and we have a pretty, uh, robust teleradiology service. So, you know,

12:17

sometimes I'll get phone calls, um, from referers, um,

12:21

and they'll ask me to throw in a classification system,

12:23

in which case I'll ask them which classification you would like me to use,

12:27

and I will look it up and I will, uh, provide that. Um, but,

12:33

um, if you are going to grade it or give a classification, i I,

12:37

I would recommend, you know,

12:39

putting in parentheses somewhere in your impression or your findings,

12:42

at least you know, what classification you are using. Um, you know, because,

12:48

um, you know, uh, I think the Hep D or, or the, uh,

12:52

the other classification I was mentioning, you know, there's overlap. Um,

12:56

some people try to divide it into like five classifications.

13:00

Some people have come along later, like the Hep D group, um,

13:04

have tried to distill it down to three to try to make it simpler to decrease

13:08

that inter and intra observer variability. But, uh,

13:13

to answer your, your question, a long-winded way, I, I describe,

13:18

and, and the way I work it is, uh, kind of like what, what I was doing, uh,

13:23

trying to, uh, highlight earlier. Uh, and sorry if I didn't,

13:27

it didn't come across, but I basically work from,

13:30

from the articular surface towards the parent bone or

13:35

lesion bed. And I basically just describe,

13:39

and then I add a summary line,

13:41

whether I think this is unstable or stable. Okay?

13:45

And if I'm not sure, then I, then I say, I'm not sure, you know, I,

13:49

I'll say uncertain or potentially unstable, something like that.

13:53

But in this case, because of the fluid cleft or the,

13:56

at least the partial fluid cleft, that's, and, and the cyst right here,

14:00

I would read this at least, you know, concerning or,

14:03

or potentially unstable, you know, as the patient is flexing and extending,

14:08

you know, maybe the shearing injuries, what have you, from whatever activities,

14:12

it may eventually make this a fully unstable and, and hopefully not, but,

14:17

but, uh, that's how I would read this case. So, so in general, I describe,

14:22

but, uh, depending on the surgeon, um, you know, uh,

14:26

if they ask for a classification, then I, then I do provide it. But, uh,

14:30

oftentimes I'll have to look that up, um, because there's just, uh, quite a few.

14:35

Um, to your second question, if I remember, uh, format,

14:39

I'm flexible for our trainees here, uh,

14:42

especially the younger trainees first and second years,

14:44

who are starting to rotate through on, on M-S-K-M-R-I, uh,

14:48

they love to do templates. Me personally and,

14:52

and my colleagues and mentors, uh, including, um, Dr. Resnick,

14:57

for those of you who are familiar with the, uh, MSK radiology literature, Dr.

15:01

Re, we, we tend not to use templated reporting.

15:06

Uh,

15:06

we tend to just lead off with the main finding and answer the

15:11

clinician's questions. Um, I find it difficult for,

15:16

for myself to toggle through and try to fix reports,

15:20

to try to figure out what my trainees are trying to say sometimes.

15:25

And also too, the injuries can be so complex, you know, and,

15:29

and what we like to do is if we can tie the,

15:32

all the findings and use Occam's razor to come up with a

15:37

single diagnosis that ties together all the findings and summarize,

15:43

that's what how we'll tend to, um, dictate. So for instance,

15:48

you know, just, uh, going to, let's say one of our previous cases,

15:53

let's take this case for example. Okay? So this ACL injury. But, you know,

15:57

if I get a good history of, let's say, you know, it's,

15:59

it's still skiing season where, where, where we're at in California, um,

16:04

you know, early spring, but, you know, let's say I get the history of, you know,

16:09

skiing injury, pivot shift, mechanism of injury,

16:12

then I'll go through and I'll say, you know,

16:14

findings compatible with pivot shift mechanism of injury as characterized by,

16:19

and then I'll list all the pertinent findings. You know, in this case I'll say,

16:23

you know, uh, anterior complete anterior cruciate ligament tear,

16:27

comma bone contusions or osteochondral fractures,

16:31

let's say at the posterior aspect of the lateral tibial plateau, comma,

16:36

you know, sometimes there's that subc chondral fracture at the condylar patella,

16:41

ssus comma,

16:43

and then any meniscal tears or medial and lateral supporting structures that,

16:47

uh, accompanying injuries that you may have. So I,

16:50

I will tend to lump and try to, you know,

16:54

use Occam's razor. And, and again, I, I, I shy away from format. So,

16:59

but that being said,

17:01

I'm flexible and it's fine if you wanna stick to the templated

17:06

format, especially, you know, uh, learning how to read MRI early on.

17:11

It's nice to have a checklist so you don't miss anything.

17:14

And as you get more facile and, and quicker with reading studies,

17:18

then feel free, I guess, to go away from templated reporting. And,

17:23

and that's what I tell my fellows and, and more senior residents.

17:26

So that's kind of how I approach it. But for grading wise, I'm very flexible.

17:31

It doesn't, it does not, uh, matter to me. Uh, i,

17:34

I just wanna make sure that you guys are making the most important

17:39

findings and, you know, the little ticky tack minutia findings,

17:43

I try not to dinging you guys on that. You know,

17:46

I just wanna make sure that we're putting out, uh, competent and, and, you know,

17:51

quality radiologists and, and keeping a standard to our field to, to this art.