0:01

Next case, a 21-year-old, uh, woman

0:04

who had a skin ski injury, excuse me, uh, two weeks prior.

0:10

Uh, she was unable to extend her knee, her physical exam.

0:15

Um, she's also had problems with flexion,

0:18

obviously only be able to flex to 90 degrees, um,

0:20

but loss of about 20 degrees of terminal extension.

0:23

She had a two B lockman, which basically means

0:26

that her anterior cruciate ligament

0:27

clinically was completely torn.

0:29

And she had a negative posterior drawer,

0:32

which is a clinical, uh, test

0:34

for posterior cruciate ligament.

0:38

So here's her initial presenting X-rays.

0:41

Um, the frontal radiograph.

0:43

We can see, uh, findings

0:45

of a fracture involving the medial tial plateau.

0:48

It looks like it's heading, um,

0:49

and tunneling under the intercondylar eminence.

0:53

And if we look at the lateral view,

0:54

this confirms the presence of an intracon

0:57

or eminence avulsion fracture.

0:59

Remember, the ACL kind of runs usually parallel

1:02

or slightly steeper to bloomin SATs line.

1:04

So this is kind of in line of

1:06

where we'd expect the ACL to be.

1:09

So instead of, uh, an MRI, this patient

1:14

actually underwent a CT in their initial diagnostic workup.

1:19

And no surprise here we can see this elevated bone fragment,

1:22

uh, comprised of the tibial footprint

1:25

of the anterior cruciate ligament.

1:27

And as I stressed earlier, even though this is a ct, you can

1:32

sort of look at other ligaments for gross pathology,

1:35

and we can see that indeed this posterior cruciate ligament

1:38

grossly looks intact.

1:40

This is where the ACL we'd expect it to be attaching

1:43

to the proximal tibia.

1:44

And of course, we have a he arthrosis, uh,

1:47

within the joint space.

1:48

So let's move on to the MRI to see exactly

1:51

what is going on in this knee.

1:54

So let's, uh, let's not talk about the elephant in the room

1:57

right off the bat, but let's talk about the medial

2:00

supporting structures, which, uh, Resnick, uh, Dr.

2:02

Resnick gave you a nice overview,

2:04

and this is where sometimes those classification

2:06

systems can be problematic.

2:08

What do you do when you have a tear

2:11

of the deep meniscal femoral portion isolated Here,

2:14

you can see it's a volt off the femur,

2:17

but you have an intact, uh,

2:19

superficial portion of this ligament.

2:21

Uh, is this grade one and a half? Is this grade two?

2:25

This doesn't quite fit in those, um, systems where it's, um,

2:29

thought that the tear, the, the failure

2:33

of the MCL complex goes from a superficial to deep order.

2:37

So in case in this case, you can see

2:39

that this vols along its deep margin,

2:41

the meniscal tibial portion,

2:43

which we can see here indeed is intact.

2:46

We can see some osseous

2:47

contusions in the medial compartment.

2:49

So we're gonna move over centrally to talk about the, um,

2:55

avulsion fracture of the intercondylar eminence.

2:57

And of course we can see all the

2:58

Edema associated with this.

3:01

And, uh, the reason why we might wanna get an MRI obviously

3:05

is not to confirm the presence of this fracture,

3:07

but to also assess its, uh,

3:10

reducibility at the time of surgery.

3:12

Because what you wanna look for is if there's any entrapment

3:15

of soft tissue structures, uh, beneath the bone fragment.

3:19

And those namely could be portions of the menisci,

3:23

or in this case, this, uh, structure.

3:26

Not in this case, but what I'm showing you here is the

3:28

transverse inner meniscal ligament.

3:30

This can sometimes be entrapped below the bone fragment, um,

3:34

precluding adequate operative reduction, um,

3:38

when the patient's go in for surgery.

3:41

So I believe in your image stack,

3:44

you should have the scope images.

3:47

And here you can see this elevated bone fragment.

3:51

And typically these are gonna be repaired using a trans

3:53

osseous tibial tunnel technique.

3:55

And you can see that the suture, uh,

3:57

sutures have been passed to basically grasp the distal ACL.

4:01

Of course, they're gonna evaluate the ACL arthroscopically

4:04

as well to see if there's any augmentation procedures

4:07

or anything else they need to do with the ACL.

4:09

And here it is being reduced, uh, back into, uh,

4:13

near anatomic position.

4:15

I can show you the follow-up radiographs.

4:18

I can say I've seen quite a few of these

4:20

in the vast majority of them,

4:22

there's gonna be some residual elevation

4:25

of those bone fragments.

4:26

They're not always perfect, um,

4:28

but you will see some OSCE irregularity

4:30

on follow-up radiographs.

4:33

So, uh, these are the surgical findings.

4:36

Examination under anesthesia, of course, uh, uh, um,

4:39

significant lockman test, a pivot shift test,

4:42

which I won't go into too much detail,

4:44

but that's one of the shifts.

4:45

The tests that they will do, uh, to, uh,

4:48

determine the integrity of the ACL.

4:50

And then here are clinically,

4:52

and this is again, exam under anesthesia,

4:55

had a grade one injury, so more of a low grade injury.

4:59

The exam under anesthesia affords, um,

5:02

the surgeon the ability

5:04

to examine the knee without the patient guarding.

5:08

'cause sometimes in the acute or even subacute stages

5:10

of the injury, the patients will tense up

5:13

and preclude an adequate evaluation.

5:15

So before any of these surgeries are performed,

5:18

these surgeons will perform an examination under anesthesia.