0:00

So for this second case,

0:02

I believe the history was an adult with status

0:07

post fall. So again, I like my crons on top,

0:11

we'll put a sagittal fluid sensitive along with, uh,

0:16

an axial at the, uh, bottom corner. So right off the bat,

0:20

we can see that there is a

0:24

fracture and some bone contusions, uh, here and there.

0:27

But obviously the fracture at the, uh, uh, uh,

0:31

beneath the lateral tibial plateau in this patient who, uh, had,

0:37

has fallen the crux of this case.

0:40

And the point of this case was we were trying to show okay,

0:44

that there's actually a subtle, uh, gon fracture. And obviously,

0:49

hopefully, uh, you know, when you're reading your MRIs, hopefully you, uh,

0:53

get an X-ray or, or given an X-ray with your interpretation. Okay?

0:59

But, uh, this is, uh, this is what's called a sagon fracture. Uh,

1:04

and these are typically gonna be pathognomonic, um,

1:09

um, especially on radiographs to evaluate for, uh,

1:13

anterior cruciate ligament tears, which we don't have here. But,

1:18

uh, some of, some of, uh, some, some people in the class did, uh,

1:22

question whether there was, um, uh,

1:24

a partial tear of the ACL totally understandable because, uh, you know,

1:28

they called, they mentioned this, uh, uh, gon fracture, okay?

1:34

And, um,

1:35

if there is not a fleck of bone in this region on a corresponding

1:40

X-ray, you still can't have what's called a soft tissue sag injury.

1:44

So that's still possible things to be, uh, uh,

1:48

aware of too with these SAG injuries. Um, because some authors believe,

1:53

uh, because of the way the enthesis or the way the fibers are inserting into the

1:58

bone here, you're not always gonna see, uh,

2:01

a robust marrow edema to draw your eyes to a,

2:05

a potential injury or gon, or, uh, any avulsion fracture.

2:10

So that's why a nice radiograph would, would really, uh, uh, be beneficial.

2:15

And if you don't have one, you can certainly recommend one. Okay.

2:19

So along with these two, uh, fractures, we have, uh, you know,

2:23

some tearing, uh, of, uh,

2:27

the medial meniscus with peripheral extrusion,

2:29

or arguably a flap interposing itself between the tibial collateral

2:34

ligament and the peripheral aspect of the medial, uh,

2:38

tibial plateau and arguably some, uh, reactive marrow edema, okay?

2:43

Already starting at the, uh, at the corner here at the, uh, tibial plateau.

2:47

And sometimes when you have meniscal tears,

2:51

they can actually also erode okay. Into the bone. And when you see an, uh,

2:55

radiograph with an erosion that's important to keep

2:58

On the differential along with inflammatory arthropathy such as, uh,

3:02

rheumatoid arthritis or even gout, right? Um, arguably there's also,

3:07

uh, some people in the class called a, a tear of the lateral meniscus.

3:11

I did give credit for that because, you know, there,

3:13

there is some signal change in here, okay? Um,

3:18

and, um, that I believe,

3:23

oh, yes. And there was also, uh,

3:27

a disruption or injury okay, of, uh,

3:31

the arcu with ligament right here, okay?

3:34

Which is this structure right here. Now, now,

3:38

I always get the question, I,

3:40

I usually get the question from my trainees at least. Okay?

3:43

Where is the RQ ligament? Okay? And to be honest with you,

3:47

it's a thin slip and it's, it's, for me at least, I find it difficult to, to,

3:52

uh, pinpoint oftentimes even on an MRI of the knee. But,

3:57

um, especially when I'm dealing with, uh,

4:00

someone that may come in with an ACL injury or pivot shift mechanism of injury,

4:05

anytime I see a, uh, edema at the posterior lateral corner of the knee,

4:10

as in this case right here, i, i,

4:13

I will oftentimes just suggest that, you know, um,

4:17

these findings raise the possibility of injury to the arcuate ligament. Okay?

4:22

And, uh, especially when I'm reading on my one Tesla or less, uh,

4:26

magnets, we also read for sometimes a 0.35 magnet.

4:30

When I just see edema back here, I'll just,

4:33

I'll just raise the possibility of,

4:36

of that arcuate ligament or posterior lateral corona injury.

4:39

And we kind of talked about those structures in, in the last, um,

4:43

last week's session. But, um, but for, as a refresher,

4:48

okay? That arcuate ligament okay,

4:50

is AY shaped ligament arising from the fibular head,

4:55

okay? And it's, uh, it's stem,

4:58

it stem arises from the fibular head, and it's,

5:01

and it has two limbs that bifurcate, uh,

5:05

more proximally and one limb goes out more

5:09

medially and blends with the posterior joint capsule and the, uh,

5:14

OPL, okay? Or that oblique, uh, posterior ligament, okay?

5:18

And then the other limb, okay, I'll try to, let's see if this works here.

5:24

Okay. The other limb kind of branches off and shoots more, uh,

5:28

superior laterally and blends with the capsule and, uh, the, uh,

5:33

and extends towards the lateral gastro anemia muscle. Okay? But anytime,

5:38

as I, as I said, anytime I sort, sort of see a demon, this, this region,

5:42

I'll raise the possibility of an arcuate, uh, injury or sprain or tear,

5:47

at least.