0:00

The second common pattern we see is supination

0:04

abduction with two stages.

0:07

Stage one is rupture of the lateral ligament shown here

0:11

in diagram B,

0:13

or a transverse avulsion fracture involving the distal

0:17

fibula shown in C and d.

0:20

Here the fracture fragment is larger.

0:24

Alright, stage two is a problem on the medial side,

0:29

classically described as a compression fracture

0:33

obliquely oriented of the medial mais.

0:36

Although I've seen examples

0:38

where there is a deltoid ligament problem

0:41

and not a compression fracture.

0:45

I wanted to show you an example here.

0:47

As we look at transverse images, superior to inferior,

0:52

we can see disruption

0:53

of the anterior talo fibrile ligament shown

0:56

by the white arrows.

0:58

And then as we proceed downward,

1:00

we can see the calcan fibrile ligament is also torn.

1:05

Alright, so here is a stage one injury with rupture

1:10

of the lateral ligaments.

1:12

And by the way, the posterior tail fbri ligament is often

1:16

spared in this.

1:19

Now what about these lateral ligaments?

1:22

When supination abduction occurs

1:26

with plantar flexion of the foot, the typical

1:30

stabilizer laterally is the anterior Palo fbri ligament.

1:35

So the first ligament to fail is going to be the anter

1:40

halo fibrile ligament.

1:41

After that, the other two low lateral ligaments may fail.

1:46

If we look at the opposite situation,

1:49

rather than plantar flexion of the foot, let's look at

1:53

dorsiflexion here.

1:56

The calcaneal fbri ligament becomes the main lateral

2:00

stabilizer of the ankle.

2:02

So here is one of the general exceptions to the rule.

2:06

The rule being and cited

2:08

by most experts is first the anterior

2:11

Palo Fbri ligament occurs

2:13

and then the calcan fibrile ligament tears.

2:17

Okay? So that it is unusual, it is said

2:21

to get isolated tearing of the calcan fibrile ligament.

2:25

But this does occur with a supination abduction injury

2:30

when the foot is dorsi flex.

2:33

And here's an example showing you that particular finding

2:38

with an intact posterior talo fibular ligament.

2:43

The third mechanism described by loggy Hansen

2:48

is pronation external rotation with four stages.

2:53

Things begin now on the medial aspect with rupture

2:57

of the deltoid

2:59

Uh ligament or an uls that's shown in figure B

3:03

or an avulsion fracture of the medial maus,

3:06

typically transversely oriented,

3:09

often low down in this case not so low.

3:12

Low down stage two is all of those findings.

3:17

And now rupture of the anterior tibial fibrile ligament

3:21

or an avulsion fracture of the tibia fibrile.

3:24

And that's shown here.

3:26

Okay, in diagram D, stage three

3:32

is all those findings.

3:33

And now the classic supra syndesmotic fracture of

3:39

the uh, fibula shown

3:42

here in diagram E.

3:44

Okay, right here.

3:47

And then finally stage four is

3:51

stage three plus rupture

3:53

of the posterior tibial fibular ligament

3:55

or an avulsion fracture at its attachment site.

4:00

So what we will see here classically are

4:04

transverse low fractures of the medial MOIs

4:08

and a supra syndesmotic fracture of the fibula.

4:12

Let's look at an example, not the prettiest of pictures.

4:16

Stage one deltoid ligament injury.

4:19

Stage two, disruption

4:21

of the anterior tibial fibula ligament.

4:24

Stage three, supra syndesmotic fracture of the fibula

4:28

with a lot of edema.

4:29

Stage four, fracture

4:32

of the posterior malus at the attachment

4:35

of the posterior tibial fibula.

4:37

Wait a minute, the fourth pattern is pronation abduction.

4:42

It's a lot like the last one.

4:43

Pronation external rotation

4:46

with only three particular stages that have been emphasized.

4:49

This is an uncommon pattern in my experience.

4:53

Stage one evulsion fracture.

4:55

The medial mavis, you see it in diagram B

4:59

or rupture of the deltoid ligaments shown in diagram C,

5:03

stage two where those findings plus rupture of the anterior

5:07

and posterior tibial fibular ligaments shown in

5:11

these two pictures.

5:13

Okay, uh, here.

5:15

And then stage three shown in F is a supra syndesmotic

5:20

fracture of the fibula.

5:22

Let's look at an example.

5:23

Here is a stage two injury related to pronation abduction.

5:28

Stage one. We can see indeed the deltoid ligament problem

5:33

at the top image.

5:35

Okay, we can see it here as well.

5:37

And then both anter

5:39

and posterior syndesmotic ligaments have been torn.

5:43

PAB injury Stage two.

5:48

The final pattern described by logging, uh,

5:51

Hansen was pronation.

5:52

Dorsiflexion. And it's this pattern related to axial

5:56

Load that we get multiple fractures, various stages,

6:01

what fractures, but we can get fractures involving the

6:04

medial maus fractures involving the anterior margin

6:08

of the tibia, fractures of the fibula as well,

6:11

and even intraarticular fractures of the tibia.

6:16

So a lot of fractures occurring in the distal tibia

6:20

and fibula, some comminuted.

6:24

Now to complete our story of mechanisms here, I want

6:28

to at least just show you pure axial compression here with

6:33

fractures of the calcaneus ali tibia

6:36

and less commonly the uh, uh, male eye.

6:40

All right, this is pure axial compression

6:43

and I wanted to show you pure dorsi fraction

6:47

where the wider antra aspect

6:49

of the talus engages the ankle mortis.

6:53

This produces an open book injury

6:55

of the syndesmotic ligaments

6:57

and may be associated with isolated involvement

7:01

of the calcaneal fib ligament.

7:03

Here's the tearing of the anterior tibial fibular ligament,

7:07

and here is the tear of the calcan fibular ligament.

7:12

So when you see isolated calcaneal fibular ligament injury

7:17

without tearing of the anterior talo fibular ligament,

7:21

these are the mechanisms.

7:23

Here's the tear of the calcaneal fib.

7:25

Pure dorsiflexion ankle injury, supination abduction,

7:31

ankle injury with dorsiflexion and a sub joint injury.

7:36

'cause remember, this ligament also sta stabilizes

7:40

the subular joint.

7:42

To summarize, you look at the fibula if you're dealing

7:45

with an oblique or spiral paray desmo fracture.

7:50

Think of external rotation.

7:52

If you're dealing with a transverse

7:55

or blank paray,

7:56

desmo fracture abduction is part of the injury.

8:00

If you are dealing with a transverse iny desmo fracture,

8:05

think of supination.

8:07

And when you deal with an oblique

8:09

or uh, transverse supra syndesmotic fracture, think

8:14

of pronation.

8:16

And on the medial side, if you're dealing with a

8:20

vertical fracture like this, think

8:22

of abduction when you're dealing

8:23

with a transverse lower fracture.

8:26

Think of abduction or external rotation.