0:01

So that's ACL reconstructions.

0:04

We'll move on to the medial side of the knee,

0:07

and I won't talk about medial collateral ligament

0:10

reconstructions, but I'll spend a little bit

0:11

of time talking about medial patella femoral

0:14

ligament reconstructions.

0:15

The reason why is there's not a lot of literature on this

0:18

and I looked around and found this one paper, uh,

0:22

not too long ago looking at MPFL reconstructions.

0:25

And the unfortunate thing is

0:27

that the reconstructed MPL fell can basically

0:29

look like anything.

0:31

In this one paper, they found that the average, uh,

0:34

thickness was six millimeters.

0:36

About a quarter of the graft were hypot hyperintense.

0:39

That means the other 75% were, you know, intermediate

0:43

or hyperintense on appearance.

0:45

And furthermore, intact grafts can appear lax.

0:50

So they found that when comparing to like clinical outcomes,

0:53

and that is, you know, patients with tele femoral laxity

0:56

and needing a second reconstruction,

0:59

that the graft appearance was not associated

1:01

with any postoperative pain,

1:02

patella femoral arthritis or graft failure.

1:06

They did find that NPFL revisions were more likely in non

1:11

anatomic placement of femoral tunnels.

1:13

So here is, uh,

1:15

what they looked at when they studied these MPFL

1:19

reconstructions and RES Dr.

1:21

Resnick gory talked about this.

1:23

There are kind of three bony landmarks at the

1:25

medial aspect of the knee.

1:26

In front you have the medial epicondyle

1:29

at the top you have the adductor tubercle,

1:32

and behind you have the medial gastroc anemia, tubercle,

1:35

or origin of the medial gastroc muscle and tending.

1:39

So your reconstructed MPFL ideally should

1:42

live in this triangle.

1:44

And when they overlaid the failures here highlighted in red

1:48

ones needing revision NPFL reconstruction, they found

1:52

that they lived outside of this triangle designated

1:55

by those three vertices.

1:59

Here's just a couple examples

2:01

of different NPFL reconstructions and complications.

2:05

Here's a patient, uh,

2:06

who had ongoing patello femoral instability

2:09

after reconstruction.

2:11

And here we can see this is approximately the location

2:15

of the medial epicon.

2:17

So ideally this tunnel should have been placed behind this.

2:20

So this was a little bit too far anterior.

2:23

Remember, the reconstructed ligament can look like anything.

2:27

Um, this one happens to be low cytal intensity,

2:29

but looks attenuated in its mid portion.

2:32

We move. This patient unfortunately had

2:34

to ongo undergo a second procedure, which was a tuber,

2:37

typical tibial tuberosity transfer.

2:41

Here's an example of a medial patella femoral

2:44

ligament reconstruction.

2:45

Patient felt a pop standing up.

2:47

Um, you can see the reconstructed ligament.

2:50

Actually it looks pretty good. The interference screw

2:53

and the patella looks pretty good,

2:54

but there's a lot of bone marrow edema.

2:56

And if we look on the corresponding, uh, CHO

2:58

Image, the pop was

3:00

that this patient suffered a fracture probably as a result

3:03

of the tibial interval screw creating a stress

3:06

riser in that patella.

3:08

And finally, in this last case, here's just an example

3:10

of a patient with infection

3:12

of their reconstructed medial patella femoral ligament.

3:15

Here you can see it's clearly failed at the patella

3:18

attachment has a redundant appearance elsewhere

3:21

and the screw has basically construed out

3:23

and everything had to remove.

3:25

Patient had to undergo a washout and long-term antibiotics.