0:00

The history here was 45 year old female with mass felt and

0:06

radiating pain. Again,

0:08

let's get our images and we'll have one sagittal.

0:13

Let's do axis,

0:18

and we can do one Corona here.

0:23

Okay. And then again,

0:26

going through the checklist, whatever, um, approach, um,

0:31

you have developed for yourself. Uh,

0:33

I start with the achilles tendon on sagittal images.

0:38

So looking at the Achilles tendon, we can look at both on, on sagittal and,

0:42

and axial images.

0:49

I think for most part it looks okay. I'm looking at the plantar fascia looks.

0:54

Okay. We can look at the plantar fascia on coronal images here. The, the,

0:58

if you see the angles and the ankle are completely off,

1:01

depends on like how the patient had his foot, uh, placed in the scanner.

1:07

Yeah, trying to get to the plantar fascia insertion here onto the calcaneus.

1:11

Looks fine. Then moving on to ligaments.

1:17

Okay, so at least plantar fascia looked. Okay.

1:19

Now coming to the ligaments on axial images.

1:25

Start with the, the tip fs, the distill and,

1:27

and anterior and posteriority of fibular ligaments.

1:30

I don't see any signal abnormality here.

1:33

Moving on to the level of the,

1:35

so see how the distill fibula from flat inner surface changes to the concavity.

1:41

So when you have that concavity, that's your ular fossa.

1:46

So this is where your anteriority fibular and the posterior tunnel fibular

1:49

ligaments, sir.

1:50

And this is your cal fibular ligament.

1:54

There's a little bit of fluid in the peroneal tendon sheets,

1:59

but otherwise these tendons are looking okay.

2:01

The medial flexors are looking okay. The interior extensor tendons are looking.

2:06

Okay. So the, the, the, the, the finding that stands out is this lesion are,

2:11

uh, brown lesion in the tarsal tunnel.

2:16

And that that, and that's where the marker is placed.

2:19

This is where the patient was feeling a lump. So anytime you have a lesion, it,

2:22

it's, it's, this is AT two sequence. It's T two bright.

2:26

So here we need to give contrast and see if it enhances it.

2:29

Just a simple ganglion cyst or is it a solid enhancing lesion.

2:36

And this is my post contrast axial image, not fat saturated,

2:39

but we can see that it's enhancing. So it's, it's an, um,

2:44

enhancing lesion in the tarsal tunnel along the neurovascular bundle.

2:47

So it's enhancing, so it's not a ganglion cyst. So the other cl um, common, uh,

2:51

differential that we need to consider in this location because it's along the

2:54

neurovascular bundle is an off sheet tumor. So, um,

2:58

probably a schwannoma that would be a working diagnosis on this case.

3:05

The other thing that we can see is like if you see this is your or your tibial

3:09

nerve or yeah, towards the foot side, it has already divided.

3:13

I was trying to show, yeah, this is where your, uh, tibial nerve is.

3:17

And as we come down at this is where, at the level of the ankle,

3:20

it passes through the tarsal tunnel, which is, um,

3:24

formed by the bones medially and laterally is the flexor ulu,

3:29

or on the, on the medial side is the flexor ulu,

3:32

and you have those flexor tendons along with it. And as we go towards the foot,

3:35

the posterior, uh,

3:37

tibial nerve divides into the median and lateral plantar branches.

3:42

So this is where the nerves can get compressed.

3:45

And this is clinic would be known as tarsal tunnel syndrome. So that's,

3:49

that's the main finding in this case. Everything else, uh, was, okay.

3:53

So couple points about tarsal tunnel syndrome.

3:57

It refers to entrapment neuropathy of the posterior tibial nerve or its branches

4:01

in the tarsal tunnel. And a lot of times it's idiopathic, no causes identified.

4:06

It could be just, um,

4:07

scarring that we don't see or some nerve dysfunction there.

4:11

But if you see something on imaging, most likely if you see a, a lesion, um,

4:16

most commonly, um, commonly seen are gallian cyst.

4:20

You can get bone, bone s spurs after calcan fractures that heal.

4:24

Varicosities is a common cause. osi,

4:27

synovitis of the flexor tendon tumors like schwannoma and lipoma,

4:30

as in this case, some, um, accessory muscles can be present.

4:34

And just because there is more muscle, same amount of space,

4:37

it can lead to compression, synovial hypertrophy.

4:40

People who have hindfoot valgus again, um,

4:42

they stress out more on the medial side so the nerve can get stretched and

4:46

compressed. So flatfoot,

4:48

post-traumatic fibrosis and in patients with post trigonum syndrome.

4:52

So here is an example of a ganglion cyst, AT again,

4:55

AT two bright lesion that's non enhancing.

4:57

So that's causing compression of the nerve in the tarsal tunnel.

5:01

And this was an interesting case here.

5:03

Now this is where your medial post medial side is tarsal tunnel,

5:08

and we have the three tendons here, to be honest, posterior, um,

5:12

flexor digital flexor lysis.

5:14

And what we see there is like an fourth muscle here.

5:17

So this was an example of accessory muscle that was resected and the patient

5:22

had, uh, relief of symptoms after removal of the accessory muscle.

5:27

So this was a accessory flexor digitor muscle there in the tarsal tunnel.

5:32

So always make sure while you're looking at your ankle images,

5:35

there's no space occupying lesion in the tarsal tunnel,

5:38

no bone spur from tri calcaneal s spurs or no scarring that's affecting the

5:42

nerve. So that was your second case

5:47

Question.

5:48

Yes.

5:49

Uh, when you're assessing for those accessory muscles,

5:53

what kind of level do you look at? Because obviously the normal musculature, um,

5:58

is coming down towards there. So what,

5:59

what's the landmark for where the tassel tunnel commences and therefore you

6:02

shouldn't have any muscle belly, visible

6:05

Muscle, uh, belly. So right at this level, like at the level of the ankle,

6:08

if I go down right here at the level of the ankle,

6:11

so you're very close to the joint, that's where you says you,

6:14

if you go up in the leg towards the distal tibial and start getting muscle.

6:17

So you have to be, uh, at or below the level of the ankle joint.

6:22

Thank you. I, I had another question, if you don't mind.

6:27

Just a general anatomical question about the superficial component of the

6:31

deltoid ligament, which uhhuh,

6:32

sort of what's your checklist when you're assessing that?

6:35

Um, so deltoid, we can start by, we can, uh,

6:39

I usually keep an axial and a coronal image. Let me pull up a coronal image.

6:45

Okay, start scrolling.

6:50

So this would be your deep deltoid and let's see where these images linked.

6:56

Okay, so on the axial images, when you go past the here, like,

7:01

um, the angle is a little off,

7:03

but this is where your deep deltoid would be starting from the medial Manus to

7:07

the tails. This is your deep deltoid right over there. If you see this band,

7:11

so superficial deltoid has couple band, the most common ones, um, um,

7:16

or the,

7:17

the one that is consistently identified on imaging is the tibial spring that

7:21

arises from the tibia and inserts onto another ligament,

7:24

which is the spring ligament and the SMO band of the spring ligament.

7:28

So if I'm scrolling my coronal images here,

7:30

you see that that's your tibial spring because it'll continue down.

7:33

Its going towards the, um, I'm sorry, the angles are a little off.

7:38

I can show it to you on another angle where the angles are like normally we,

7:42

we plan it, um, uh, like along the long axis of the tibia.

7:47

That's your coronal plane. Um, so here it's a little off. So,

7:51

but this is where your tibia spring is.

7:53

The other way to identify spring will be, um,

7:57

the black structure that is deep to TBIs posterior tendon.

8:00

So this is where your TBIs posterior tendon,

8:02

and this is where the anterior tails is.

8:04

So the black structure that you see between anterior tails and TIUs

8:09

posterior your spring,

8:10

and this SMO band of the spring ligament can be as thick as the tibia posterior

8:14

tendon. It looks like there are two li uh, uh, tendons there.

8:18

But this is the spring.

8:19

And the part of the band that goes from the tibia to the spring ligament is your

8:24

tibia spring ligament. Okay?

8:26

That's the most important component of the delta ligament that is seen on

8:28

imaging. Now, there are other smaller components, which is the tibio, calcan,

8:33

tibio navicular. Now those, if you're lucky, maybe this is the navicular,

8:38

if you're lucky, you'll see like a navicular band, like any, like,

8:42

you just have to know the names. And then you can follow,

8:44

the one that goes from tibia to navicular will be the tibio, uh,

8:48

tibio navicular band.

8:49

One that goes from tibia to the spring is the tibial spring band.

8:52

And then the tibial calcaneal one is this. It's more posterior,

8:55

so it's harder to identify because of the obliquity that you get on these

8:58

images. So yeah, the one that is consistently seen is the tibial spring.