0:00

We're gonna move on and talk about the tib.

0:03

Posterior tendon seen more often in women,

0:07

more often unilateral than bilateral, typically middle aged,

0:10

some of whom have an underlying rheumatic disease such

0:14

as rheumatoid arthritis, and it's this particular tendon

0:17

and its pathology that can cause something known

0:22

as adult acquired flatfoot deformity.

0:25

We're gonna talk briefly about that in a moment.

0:28

Accessory ossicles may increase the likelihood of problems.

0:33

Dear of the tibial is posterior tendon.

0:36

So let's talk briefly about adult acquired

0:39

flatfoot deformity.

0:41

A-A-A-F-D.

0:44

This is what it might look like clinically in a late stage

0:48

with a very prominent area

0:51

of deformity along the medial aspect of the angle.

0:54

To understand this, and again this is briefly,

0:57

there are three particular arches that are used to describe

1:02

the ankle and foot.

1:04

The first of these in the coronal plane is the transverse

1:08

arch composed of the metatarsal bases, Korm and oid.

1:13

A second sagittal arch located laterally.

1:16

Of course, the lateral arch.

1:18

This is a weight-bearing arch composed of the calcaneus OID

1:23

and lateral two rays of the foot

1:26

and then the medial arch, which is taller.

1:29

Okay, shown here. More flexible.

1:33

It's composed of the TAUs, the calcaneus, the canfor,

1:38

and the medial three rays of the foot.

1:41

So those are the classic arches.

1:45

A A FD is associated classically

1:48

with repetitive loading, particularly

1:51

of the medial arch of the foot.

1:54

And owing to that progressive abnormalities may occur

1:58

not only involving the tendon,

2:00

we're talking about the TBIs posterior tendon,

2:03

but other dynamic and static stabilizers as well.

2:07

Taken from uh, images from Michael Davis, a previous fellow

2:12

of ours, these are the dynamic stabilizers.

2:16

You can see the list of them shown in this image.

2:19

And these are the static stabilizers, ligaments,

2:24

and plantar fascia shown in this image.

2:28

So when the stabilizers go, you may end up

2:32

with problems in the medial arch.

2:34

There's progressive elongation

2:37

and flattening of the medial arch owing to the loss of these

2:42

uh, stabilizers.

2:44

And owing to that, there is abduction of the calcaneus

2:47

and forefoot that leads to hindfoot valgus.

2:52

If you look at the normal situation here

2:55

and compare it to this, there is now valgus alignment

2:59

between the Alis

3:01

and calcaneus, keeping in mind

3:03

that ALIS is fixed at the ankle joint.

3:06

So what you're dealing with is lateral migration

3:10

of the calcaneus,

3:12

which is increasing the talo calcan uh, angle.

3:16

Okay, this leads to, again,

3:18

a hindfoot valgus pest planus deformity

3:22

and lateral subluxation of the navicular bone in the area

3:27

of the talo navicular portion

3:30

of the talo calcan navicular joint,

3:34

about which we spoke earlier.

3:37

So when you look at this particular problem, A A FD,

3:42

utilizing any imaging method, here I show you Mr.

3:46

You're gonna see these features of malalignment.

3:49

You're gonna see midfoot collapse typically related

3:52

to a vertical orientation of the alis,

3:57

occasionally related to sag of the navicular bone as well.

4:02

You're gonna see something that I call midfoot valgus

4:06

as the navicular is sliding laterally in the region

4:09

of the al Navicular interosseous space.

4:13

And you're gonna see Hein foot valgus depart,

4:16

which you can see at the level of the calcaneus

4:19

or in a coronal section at this level.

4:23

Here's the calcaneus, here's the Taylor head.

4:27

Normally portions of the calcaneus are located under

4:31

the Taylor head here.

4:33

They are not because

4:35

of the increase in the talo calcan angle.

4:39

And in this area we would have a spring ligament,

4:42

which is clearly abnormal.

4:44

Here we have an abnormal tibials posterior tendon.

4:48

So let's look at two examples here of what we might see

4:52

with adult acquired flatfoot deformity.

4:56

These taken from Diane Flores's Beautiful article,

4:59

uh, in radiograph.

5:01

Minnie was also a co-author on that article.

5:04

And these are the arrows. You can see what they represent.

5:08

So the straight horizontal arrows are showing you problems

5:12

with the deltoid ligament.

5:14

The spring ligament is shown by the large black arrows,

5:17

and in both cases it is partially or completely torn.

5:22

The tib posterior tendon is abnormal in both cases shown

5:26

by the arrow heads and then the cervical ligament.

5:30

This is a better picture here it is here.

5:33

What happens when you have hind foot valgus normally,

5:38

as we'll talk about a little while,

5:39

the cervical ligament is obliquely oriented like this,

5:43

but as this angle increases,

5:45

it becomes horizontally oriented and indeed may tear.

5:50

So these are the features of A A FD.

5:54

Now, there's some other features that have

5:56

Been emphasized in the literature,

5:59

and I wanted to show you what they are.

6:01

There is something called talo calcan impingement

6:05

shown here where there's abnormal contact

6:09

between this region of the TAUs

6:12

and this area here of the calcaneus,

6:15

the critical angle of sain.

6:18

So you'll see bone proliferation, bone resorption,

6:22

marrow edema, and even fragmentation in this region.

6:27

And with the hind foot valgus deformity,

6:30

you can see it here, you narrow the space

6:33

between the calcaneus and fibula.

6:35

And those tissues located in this area are vulnerable to

6:40

that sort of narrowing of the interosseous space.