0:01

Dr.

0:01

Chung mentioned three major structures that are important

0:05

for, um, the integrity

0:08

of the longitudinal arch.

0:10

Uh, she primarily focused on the plantar fascia.

0:13

So here we'll talk a little bit about

0:15

those two other structures.

0:16

She mentioned posterior tubial tendon

0:19

and your spring ligament complex.

0:21

Uh, and so this case is a 77-year-old woman

0:26

who had a protruding and painful ankle.

0:30

Uh, so just starting with the patient demographics

0:33

and the history that elderly woman with foot mal alignment,

0:37

I think you should already be thinking about the possibility

0:39

of posterior tibial tendon insufficiency

0:42

and adult acquired flatfoot.

0:45

Um, I think it is challenging

0:47

to assess hindfoot valgus on MRI when it's subtle,

0:51

and there was a question in the chat earlier about whether

0:53

or not we measure angles.

0:55

Um, I, um, like Dr.

0:57

Chung, I don't love to measure things if I can help it,

1:01

I just like to get a gestalt for what's happening.

1:04

Um, if you wanted to measure, um, there is an angle

1:08

that's been proposed, the Hein foot valgus angle, uh,

1:11

from Donovan and Rosenberg.

1:14

And you've basically measured that

1:15

by looking at the most posterior slice

1:18

where you see the tibia and the calcaneus.

1:22

And if you, um, take the angle between the longitudinal axis

1:26

of the tibia and the medial wall of the calcaneus,

1:30

and it's greater than six degrees, um, that's,

1:34

uh, abnormal, uh, hindfoot alignment.

1:38

Hindfoot valgus here, I think without even measuring,

1:41

we can see that this is severe hindfoot valgus.

1:46

Um, if we look at our localizers, which give us a,

1:49

a bigger field of view to kind of give us a sense

1:54

of the overall foot alignment, we can see

1:56

that if this was weightbearing,

1:58

it looks like calcaneal pitch is

2:00

probably gonna be decreased.

2:02

And then, um, looking at the medial longitudinal arch,

2:05

it looks like if we, uh, follow the axis of our tails

2:09

with our first metatarsal shaft, it's gonna be convex down.

2:13

So compatible with PEs planus.

2:20

So, um, usually that maintenance

2:23

of the medial longitudinal arch, um,

2:26

is lost when you have problems

2:28

with your posterior tibial tendon.

2:30

Um, and then that causes the foot mal alignment, which leads

2:35

to secondary injury to the needles, the,

2:38

the supporting structures.

2:40

Um, most importantly, our spring ligamentus complex.

2:44

So looking at our posterior tibial tendon, it's actually not

2:48

horribly abnormal in this patient.

2:51

I think you might argue that there's a little bit

2:53

of increased signal, um, within the substance of the tendon,

2:57

so compatible with tendinosis,

2:59

and then some tenino synovial fluid

3:01

around the tendon compatible with penis synovitis.

3:07

And then if we turn our attention

3:09

to the spring ligamentus complex, again,

3:12

there are those three major components.

3:15

Your s medial, um, spring

3:19

ligament is gonna extend from your slum tail eye.

3:24

It's gonna form like a hammock

3:26

or a sling around the medial tail or head.

3:29

And then it's gonna attach, um, to the dorsal

3:34

medial aspect of the navicular here.

3:38

It normally should separate the medial tail head from the

3:41

posterior tibial tendon.

3:43

Here, I think a little bit attenuated,

3:45

some altered signal within it, um,

3:48

and then also some edema within the underlying, um,

3:52

medial tail head.

3:53

So this I think is not normal.

3:55

Um, interestingly, the other way

3:58

that the sial spring ligament can be abnormal is kind

4:02

of the opposite of this, where you see a thickened um,

4:05

ligament and it's thought that

4:08

because of the hind foot vgu,

4:10

you get some altered weight bearing, which is gonna lead

4:12

to thickening of the ligament.

4:14

So if you're a measurer

4:16

and you want to put calipers on it, um, it's been proposed

4:19

that a measurement of greater than four millimeters in

4:22

thickness should be considered abnormal.

4:26

So again, those medial plantar, um,

4:29

and feral plantar longitudinal components

4:33

of the spring ligament are gonna be best seen, I think,

4:36

on the axial images.

4:38

Um, to be honest, I think injuries

4:40

to these structures are a little bit more challenging

4:42

to identify and most

4:44

of them are not really gonna be addressed surgically.

4:48

Um, but important to,

4:51

to take a look at these structures also.

4:55

And then, um, because of that hindfoot vgu that we noted,

4:59

um, we're gonna get failure of the, um,

5:03

ligaments in the tarsal sinus, um,

5:05

and possibly sinus tarsi syndrome.

5:09

So we talked about how, um, the interosseous tail

5:13

of calcan ligament should be more medial, um,

5:16

and the cervical ligament should be more lateral.

5:18

Here I think it's challenging

5:20

to actually identify the ligaments, um,

5:22

because we've lost that normal, um, space, uh,

5:26

in the taral sinus,

5:28

and then the fat in the tarsal sinus itself looks, um,

5:32

fibrosed and emus.

5:34

Um, so challenging to see the ligaments,

5:36

but those findings are compatible with sinus tarsi syndrome.

5:42

And then finally, um, as if that wasn't enough, in addition

5:45

to the lateral tail calcan impingement, um, much like

5:49

that calcaneal fracture that I showed you earlier,

5:52

the mel alignment here is leading to some narrowing, um, of

5:56

that space between the calcaneus and the distal fibula.

6:00

So there's also a component

6:02

of sub fibrillary impingement here.

6:05

Um, and I had one case of turf toe, but Dr.

6:07

Chung's cases were much more, uh, interesting than mine.

6:12

So I think I'll stop there.