0:00

This one's a kind of interesting case in that this was a,

0:03

uh, 40-year-old male, uh, paramedic, uh, EMT,

0:07

who experienced knee locking, uh,

0:09

while he was performing CPR on a patient.

0:12

And he went to the er, uh, to be redu, uh, reduced

0:15

by the time he got to the orthopedic office,

0:17

his exam was pretty much normal,

0:19

but he did report a history of previous, uh,

0:23

less severe episodes.

0:26

So there are some other ancillary findings.

0:28

I'm not gonna go into, uh, tremendous detail.

0:31

He has some, probably some chondral degeneration

0:33

and fissuring in his lateral femoral tibial compartment.

0:36

But I want to focus on, which I have zoomed in here, is, uh,

0:40

you might have heard me mention when I was talking about the

0:43

popal fibular ligament,

0:44

which we can see nicely here going from the fibular syl

0:47

to the pope tendon, those popal meniscal sles.

0:51

And they're definitely easier

0:53

to see when you have a joint effusion

0:55

'cause that sort of just distends everything.

0:57

Um, but given that this case, this patient

1:01

had a known history of locking you all,

1:03

you automatically wanna start thinking of a couple things.

1:06

You know, does a patient have a bucket handle tear displaced

1:09

municipal flap, something

1:11

that's not anatomically where it should be.

1:14

You know, if the patient has a prior ACL reconstruction,

1:17

do they have a cyclops lesion

1:19

or do they have a torn ACL with an entrapped sto?

1:22

Do they have a joint body, either chondral

1:25

or osteochondral joint body?

1:27

So when patients tell you they have mechanical symptoms

1:29

particularly locking,

1:30

these are all the things you want to think about.

1:33

So as I draw your attention to this kind

1:34

of the poster lateral corner of the knee, we notice

1:38

that we don't really see those popliteal meniscal ligaments.

1:41

Well, normally here, this is where we would see

1:43

that anterior inferior popliteal meniscal ligament.

1:47

That's the first one you encounter as you go from lateral

1:49

to the central aspect of the knee.

1:51

And here, likewise, you should probably start seeing the,

1:54

the, uh, posterior superior popal meniscal

1:57

ligament or fascial.

1:59

And here, maybe this is the anterior inferior,

2:01

but instead of looking like a normal wispy ligament

2:05

or fascial, this looks a

2:06

little bit thick and, and irregular.

2:08

We don't see the posterior superior, uh, fascial very well.

2:11

If we look at the rest of the lateral meniscus.

2:14

Um, nothing much in the way

2:16

of intrinsic meniscal abnormality,

2:19

no tear or anything like that.

2:21

We can see here in this non distended knee portions

2:24

of the anterolateral ligament.

2:27

So nothing that really jumped out.

2:29

But the astute radiologists who shall remain unnamed, Dr.

2:34

Patria, uh, was the one who, uh, diagnosed, uh, this patient

2:37

with, uh, injury to the popal meniscal ligament.

2:41

And so let me see if I can show you the corresponding,

2:45

uh, scope images.

2:48

So here's the video. This is looking, um,

2:51

into the lateral compartment.

2:53

And the arthroscopist is just basically probing

2:56

the lateral meniscus.

2:57

You can see maybe there's a little bit of

2:58

Free, free inch frame along the inner margin.

3:01

This is the anterior horn.

3:03

Here's the body over here, and then this is posterior horn.

3:06

Now you can see that indeed it's grossly unstable.

3:09

And remember, those popal meniscal ligaments help not only

3:13

stabilize, uh, the pope tendon as it exits the joint,

3:16

but also stabilizes the posterior horn

3:19

of the lateral meniscus.

3:21

And so this is why the patient was experiencing knee locking

3:24

symptoms because this was basically unstable in translating.

3:28

And so if I just fast forward to here,

3:30

you can see this patient underwent a repair

3:32

and here they're just making sure

3:33

that their repair is stable

3:35

and that it's not translating forward anymore.