0:00

Moving now to posterior impingement syndromes.

0:04

So when we're thinking about posterior impingement syndrome,

0:07

this of course is impingement on the posterior

0:10

or soft tissues, uh, at the posterior margin

0:13

of the ankle articulation.

0:14

And that can occur from a variety of different

0:18

osseous abnormalities.

0:20

The ADA process that's defined

0:22

as a long posterior tailor process,

0:25

a prominent posterior superior calcan,

0:28

a prominent posterior tibia, or a prominent large O trigonum

0:32

or perhaps even fractured sada process.

0:35

So you can imagine that all

0:37

of these osseous abnormalities could place mass effect on

0:41

those posterior soft tissues.

0:43

In this case, contrast placed in the posterior subtalar

0:47

joint here, specimen photograph

0:51

showing the posterior subtalar joint tibiotalar joint.

0:55

And the point here is to show you

0:58

that there are three sources

1:00

of synovium back here at the posterior aspect

1:02

of the ankle articulation.

1:04

You've got the synovium of the tibiotalar articulation,

1:08

you've got the synovium of the posterior subtalar joint,

1:11

and you've got the synovium synovium

1:14

of the intimately associated flexor lysis longus

1:18

as it passes posterior to the ankle articulation.

1:22

So you see that this area back here is really rich

1:26

with potential areas of synovium that

1:29

with mass effect could have synovial proliferation,

1:33

irritation, and secondary pain.

1:39

So in this case, you can see

1:41

that we've got a long posterial process

1:44

and possibly even a fracture through that.

1:48

So as you consider really this position

1:52

of the foot, it's been associated

1:55

or called the nutcracker type phenomenon.

1:57

So when you plantar flex the foot, you see

2:00

that the poster aspect of the tibia

2:03

and the superior aspect

2:04

of the calcaneus come in approximation

2:07

or approximate one another.

2:08

And if you've got ossea structures here,

2:11

even the synovium could be caught between the tibia

2:15

and the calcaneus

2:16

and ultimately could end up with synovial hypertrophy.

2:19

When I'm looking on my ankle films, I always try

2:22

to look closely to see if there are focal

2:24

areas of increased density.

2:26

Back here. In this case, you've got a thick Achilles,

2:28

you've got enthesopathy at the Achilles.

2:30

I always follow my flexor haliss longest.

2:33

Remember, at the level of the ankle articulation,

2:36

this muscle is the only one

2:38

where we're seeing a significant amount of muscle belly.

2:41

So you know that's your flexor hallis longest.

2:44

Here you would find of course,

2:46

NOL hypertrophy from the ankle articulation in this area,

2:50

synovial hypertrophy from the poster subtalar joint

2:53

and the flexor house.

2:55

As long as that can kind

2:56

of extend along the surface of both. Similarly,

2:58

Of course I would look for anterior tibiotalar increased

3:02

soft tissue densities as well.

3:04

So let's look at this

3:06

lateral ankle film sate a process long

3:09

poster Taylor process.

3:11

Assess the posterior soft tissues.

3:12

You see a face of CAGR fat pattern in the posterior margin

3:15

of the flexor lysis.

3:18

To me, nothing here really looks like there's

3:21

mass like synovial hypertrophy.

3:23

When you look at the sagittal stir image,

3:27

you can see a little bit of high signal intensity here.

3:30

Fally reactive marrow change in

3:32

that sate process, no fracture.

3:34

But when you look at the axial images here, you can see

3:38

that there's synovial hypertrophy along the poster.

3:41

Talo fibular ligament.

3:43

So you know, there's this idea

3:44

that you can only identify synovial hypertrophy if you've

3:48

got T one post contrast images.

3:51

But take a look at the capsule.

3:52

I mean here you're looking deep.

3:54

This is the fibular concavity, right?

3:56

The anatomic landmark that Don was describing to you.

3:59

Not a normal looking a**l fibular ligament.

4:02

Here, your poster talo fibular ligament.

4:04

A little bit ill defined,

4:06

but clearly you see this thickening back here.

4:09

There's simple fluid. This is synovial hypertrophy.

4:12

So don't feel that you're not gonna be able to make

4:15

that diagnosis without post contrast enhanced images.

4:19

Look for it. Look at the level of the joint line

4:21

and where these capsule ligaments are,

4:23

and you'll be able to identify these areas of synovitis.

4:27

Another example here,

4:29

and you can kind of get the fact that there's a plane

4:31

of lucency, right?

4:33

So a large trigonum, again, maybe a little bit

4:37

of synovial hypertrophy here, increased density.

4:40

But when you move into sagal images,

4:43

you're seeing reactive marrow changes on both sides

4:46

of that syn chondro.

4:47

There's that little bit

4:48

of synovial hypertrophy, pretty minimal.

4:51

But when you see reactive marrow changes here,

4:54

clearly those can be a good indicator that you've got pain

4:58

or could have pain.

5:00

When we think about structural abnormalities that correlate

5:03

with pain in the vast majority of cases, um,

5:06

reactive marrow change

5:07

or bone edema usually has a high correlation.

5:11

The other things often are kind of hit

5:13

or miss synovial hypertrophy.

5:15

Synovitis also associated with pain, fat,

5:18

altered signal intensity, high association with pain.

5:21

Other things may be a little bit less. So.