0:00

Now let's finish up this first lecture by kind

0:04

of coming up with a simplified analysis

0:07

of injury mechanisms.

0:09

And the way I'm gonna do this again with a diagram

0:13

I'm showing you the tibia, here is the circle.

0:16

I've placed it into a rectangle,

0:20

which is the femur.

0:21

And I've added to this the various ligaments. Okay?

0:26

These are on the lateral side,

0:28

be it the antral lateral corner,

0:31

the lateral supporting structures,

0:32

the postal lateral corner.

0:35

And then on the medial side, the same sort of thing,

0:37

adding the medial collateral ligament.

0:40

And then I've also added the cruciate

0:42

ligaments in the center.

0:45

Now as I look at it classically, these are the patterns

0:49

of injuries that we see.

0:52

Abnormal translation, particularly anter and posterior.

0:56

Yes, you can have medial or lateral as well,

0:59

but we generally deal with anterior posterior with regard

1:03

to distraction, much more commonly Valgus uh,

1:07

is the mechanism we see with medial distraction.

1:11

Lateral distraction is something uncommonly seen,

1:14

and we see that with avar mechanism of injury.

1:17

And then there are four types of rotational, uh,

1:22

abnormalities or mechanisms.

1:23

The two that I would concentrate on, the ones

1:26

that are more common involving the anterior cruciate

1:30

ligament and lateral

1:31

or medial ligaments, are these two that we've talked about,

1:35

ARI or amri.

1:36

So let's look at the classic sequence of events.

1:40

Now, there clearly are variations in this

1:44

when we have anterior translation of the tibia.

1:47

With respect to the femur, four degrees of severity,

1:51

typically the first structure

1:53

that fails is the anterior cruciate.

1:55

Then the medial and lateral supporting structures may also

1:59

fail the third of the posterior capsular regions.

2:04

And then finally, in some cases,

2:06

the posterior cruciate ligament may be torn.

2:10

So this is not invariable,

2:12

but this is the classic pattern, four degrees of injury.

2:17

Let's look at posterior translation

2:19

where there are two degrees classically.

2:22

The first is an injury involving the posterior cruciate

2:25

ligament and the second

2:27

abnormalities involving the postal lateral

2:30

and postal medial corners of the knee.

2:34

Let's look at a third scenario that is a valgus

2:38

with three stages of injury.

2:40

Classically. First would be problems on the medial side,

2:44

perhaps the medial collateral ligament

2:46

and posteriorly ligament, okay.

2:49

And other structures in the postal medial corner.

2:53

In some cases, you also have involvement of the medial

2:57

patello femoral

2:58

Reac ligaments as well.

3:01

The second an ACL injury,

3:06

the third, possibly a posterior cruciate ligament injury.

3:12

And then the rotational injuries ery.

3:15

You wanna look for abnormalities that are involving the ACL

3:19

and the lateral supporting structures.

3:21

And if we look at the opposite one, which is amri,

3:25

you wanna look for problems

3:26

of the anterior cruciate ligament

3:29

and the medial supporting structures.

3:32

So what we've done in the first, uh, 45 minutes is to cover

3:36

this particular subject.

3:38

We looked at the normal structure of human ligaments.

3:41

We've emphasized collagen framework.

3:44

And then what I've done in the major meat

3:46

of this particular lecture is look at the

3:48

footprints left behind.

3:50

Be they bruises or contusions, be they fractures.

3:54

They can tell you about

3:56

what movement has taken place in the injured knee.

4:00

And if you know then what are the primary restraints

4:03

and secondary restraints for that movement,

4:06

you'll do very well in the interpretation of those Mr.

4:10

Images.