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Transcript

- This is the Sonosite Behind the Scan webinar

called Using Ultrasound to Evaluate the Medial Ankle.

And this is the third in a four-part series

about ankle ultrasound,

and we'd love it if you could join us

on Tuesday, October 11th,

for the final webinar,

Using Ultrasound to Evaluate the Lateral Ankle.

Now, with that out of the way,

I'll get today's presentation started.

My name's Chris Pennell,

and I'll be moderating today's webinar.

Before we begin, please be advised all attendees are muted,

and you can type your questions into the Q&A box

in the toolbar located at the bottom

of the side of your screen.

And we'll conduct a Q&A session at the end

of the presentation and demonstration.

This webinar will be recorded and archived

for future reference on our webinars page.

So here with us today we have Daniel Shelton.

Daniel is the Director of Musculoskeletal Market Development

for FUJIFILM Sonosite.

Daniel has spent 18 years

as a dedicated musculoskeletal sonographer,

and 12 of those years have been here at Sonosite.

He now leads Musculoskeletal Market Development,

where he works to spread the word

about the benefits of point-of-care ultrasound.

Today's webinar is going to be a very thorough examination

of the medial ankle,

so I'll go ahead and turn it over to Daniel and get started.

- Thank you, Chris, for that introduction.

And I'm just going to jump right into the slides

'cause we have a lot to cover.

Just to reiterate, the AIUM indications

that we have gone over in the previous webinars

are listed here,

and I won't exhaust the list verbally again.

And then we're going to cover the medial ankle protocol

set forth by the AIUM.

It includes the posterior tibialis tendon,

flexor digitorum longus,

flexor hallucis longus tendon,

the tibial nerve, and the deltoid ligament complex.

So let's talk about this medial ankle joint.

As we do all these other structures,

start at the joint level, start on the bones,

and we're going to work our way superficially.

That's the best way to navigate anything in MSK ultrasound

because our bones are our roadmap and they don't change, so.

For the most part, I should say.

But soft tissue changes,

and that's why it's really tough on especially medial ankle

when there's pathology,

to start superficially and work your way down.

Because in normal cases, it's going to look okay, it's fine.

But when you're really trying to traverse difficult terrain,

when soft tissues are disrupted, ruptured, swollen,

have calcium deposits where they don't belong,

things aren't moving the way they should,

really, you have to start with your roadmap,

and that's the bones.

So let's start with the cortical landmarks,

first, of the tibia.

The fibula won't be a part of this exam,

but the talus is a big part of the exam.

So the tibia and the talus are a huge part of the exam.

The calcaneus and navicular are kind of secondary

to the majority of the exam,

but the star of the show by far is the tibia

and how the talus is secured to it,

along with how the calcaneus and the navicular

have their contributions to this ankle joint.

So let's start with the medial ankle ligaments.

And I will say this in advance,

these are the most challenging parts

of the whole medial ankle.

So if you can get through the complex anatomy,

or at least have a general understanding

that these ligaments run in a particular orientation

and you have to have the ankle positioned

in a particular way to visualize them,

I think you'll have a great time learning

and navigating these medial ankle ligaments.

First and foremost,

the deltoid ligament complex is a complex.

It is shaped like a delta or a triangle,

and that's why we think of it that way.

It has nothing to do with, you know,

delta as a number or anything like that.

But this is a large triangular ligament complex.

And deep.

We have two ligaments.

They have a similar name, so it's easy to remember.

There is a posterior tibiotalar ligament

and an anterior tibiotalar ligament.

So just remember those two.

There's a posterior and an anterior.

We never hardly focus so much on this anterior guy,

but the posterior one is much easier to visualize,

as long as you've got the foot in the right spot.

And just know that, from a stabilization standpoint,

these two guys are definitely keeping the joint

from everting or opening too much.

And that's very clear

and you could see that with the anatomy here.

But here's our two ligaments we're going to focus on.

And then the superficial structures to come.

The first superficial ligament,

it just parallels the deep posterior tibiotalar,

and that is the superficial tibiotalar.

So, easy to remember.

They are a complex.

Unless there's something wrong with them,

I will say you will not discern much of a difference

between these layers.

You can try to move and mobilize the ankle joint,

and you might see some differences in the layers there.

But I will say don't get frustrated

if you don't see a clear delineation between the two.

A lot of anatomical references don't focus on this, anyways.

They don't really even cite this ligament.

It's potentially a little bit variant.

But it does blend into its neighbor very easily,

and its neighbor kind of steals the show.

But let's take a look at what this looks like on ultrasound.

Here's our transducer position.

Here's the ligament here.

You won't see this with a relaxed ankle.

With a relaxed ankle, this ligament is tucked

and is hiding under the medial malleolus,

and you won't see it.

So we need pretty exaggerated dorsiflexion.

Keep cardiac transducer planted on the medial malleolus

and just keep an eye for the talus

to do all the mobilization.

You should see that talo, that subtalar joint right here,

swing into view just as a landmark in the FHL back here.

We're not going to focus on the soft tissues just yet,

but here's your cortical references.

Here's the superficial in the deep.

They do blend together.

As you can see here, we're just talking differences

in anisotropic artifact between these two.

They are a complex.

So don't get too hung up

on saying here's deep, here's superficial.

Just here's your probe position,

here's dorsiflexion to find them.

And in the live study, live scan, today,

we're going to go over that really nicely.

Its neighbor kind of steals the show.

It's the strongest ligament.

This is the tibiocalcaneal.

It is larger and broader.

It is thick and dense.

It does show up nicely with anisotropic artifact.

But again, it's a part of this complex.

So if there's nothing wrong with the ankle ligaments

that you're ultrasounding,

you're not going to see this huge delineation

between the layers.

But here's what it looks like on ultrasound.

So here's our tibia, here's our calcaneus, here's the talus.

So it abridges that gap.

Here's an anisotropic

or oblique deep tibiotalar ligament.

So we're running our transducer

slightly more anterior than we began.

We are a bit more mid-coronal in the shot here.

So, focusing on our cortical landmarks first,

you're going to plant the proximal aspect of the transducer

and swing the distal aspect

until you see the calcaneus,

specifically around that sustentaculum tali

portion of the calcaneus.

Its neighbor here is now the tibiospring.

This is where it gets a little bit more complicated.

Down here, joining the calcaneus to the navicular

is the spring ligament complex.

It's not the star of the show today,

it's not the deltoid complex that we're here talking about.

And it's not a part of the AIUM protocol

to evaluate the spring ligament with any level of detail.

But we do need to know about the spring ligament

because this is the only ligament in the ankle

that has a bony origin but a ligamentous insertion.

So it inserts on the spring ligament.

So this is the tibiospring ligament.

So spring ligament acts as a hammock for the talus.

And it has these fibers that literally act as a hammock

and hold the talus in position,

creating this very secure archway,

or underneath hammock,

I guess is really the only way to describe it.

But superficial to this

and blending and merging and interdigitating with this

is the tibiospring.

It's very long.

It goes all the way down here to the undersurface

of the articular cartilage surface of the talus.

So anytime we see the talus and then we see the cartilage,

if you see the cartilage,

the immediate superficial surface to that cartilage

is most likely part of the tibiospring

in an oblique fashion,

depending on how you have your transducer situated.

But spring ligament,

it's going to go from that sustentaculum tali region

of the calcaneus, the inferior, more anterior portion of it,

to the navicular.

And then it also has branches

that kind of go on the superior superficial surface

of the navicular,

but mostly it also acts as a hammock

in its insertion across the undersurface of the navicular.

So it's a big broad ligament underneath the talus.

And then this tibiospring ligament

attaches to its fibers kind of mid-hammock.

So here's the probe orientation.

We're aiming from the arch of the foot up.

So superior lateral,

I guess would be the angle.

So the probe is laying inferior medial,

aiming superior lateral.

We're then going to fan the transducer tail,

or the handle of the probe, up and down

until we see these landmarks come into play.

If you see that talus cartilage,

you're really, really close,

then I need you to fan your distal portion

of the transducer here

until we see the navicular, the more superficial guy.

And then deep, we're going to see the calcaneus

and the sustentaculum tali of the calcaneus show itself.

And just as a landmark, here's a flexor digitorum longus

sitting on top of it.

And then as another landmark up here to the navicular side,

we can see a oblique posterior tibial tendon,

which we'll get into

after we get out of these ligaments.

But here's the talus, here's that spring ligament complex.

It's all of this.

Even though we see one really nice cord

of fibers coming into play,

this is all still part of that ligament complex underneath.

So it's just not what we're focusing on here.

We see that really nice central cord

bridging these two bones.

And then we need to keep in mind

that that tibiospring ligament is now coming at us.

So we're seeing a cross section

of the tibiospring ligament here.

So we're going to rotate our transducer,

and we'll do that in a live study.

And now we have a cross-section of the spring ligament,

which is here.

And then we have the interdigitated tibiospring ligament.

So here's tibia,

here's the neck of the talus.

And then incidentally,

actually, what we're seeing here is a bit

of the tibionavicular ligament superficially

and a bit of the tibiotalar ligament anteriorly,

the deep tibiotalar.

So we're not focusing on those,

but that is what's sandwiching the tibiospring.

So in this particular slide,

we're going to windshield wiper the distal aspect of the probe.

We're going to plant the tibia side of the probe

and we're going to swing it across

until we see navicular superficially.

And then we're going to swing it back

until we see the calcaneus deep.

And then we're going to split the difference between those two

and do a dynamic maneuver next.

So here's that slide.

So here's superficial navicular

and then here's the deep portion

as we slide back across to the calcaneus sustentaculum tali.

The calcaneus comes into play.

And then we're going to split the difference between those two

and rest our transducer right there in the middle.

And then we're going to do this dynamic maneuver.

So we're going to invert the foot,

and what that's going to do

is kind of try to clap the calcaneus

and the navicular together.

So I want you to grab the distal foot

and pull it inward towards the arch

and towards the calcaneus

and try to get these two bones to touch.

And that's going to relax the tightness

of the spring ligament a little bit,

enough to cause it to stretch

and to contract here on the tibiospring side.

So I'm going to hit play,

and I want you to watch this central band right here.

So here's the spring ligament complex

hugging the cartilage.

Here's some inferior fibers

of the posterior tibialis tendon.

And there an anisotropic.

So you can see this interface.

When we start inverting the foot,

you'll see a glide here.

But particularly, I want you to watch this structure here

bounce on top of the deep tibiotalar ligament

and underneath the tibionavicular oblique segment here,

which we're not focusing on.

We're focusing on this central portion

going to the tibiospring complex right here.

So spring complex, tibia follow these fibers when we invert.

And that's what we're seeing here.

So watch that bounce right here

as it relaxes and stretches, relaxes and stretches.

And you can see these fibers and how they're connected.

And the beauty of ultrasound

is that we have the ability to make these tissues move.

And sometimes that's the only time

you can delineate structures.

Even on MRI,

there's lots of notes in the radiology references

about how some of these ligaments,

you really can't distinguish one from the other.

And that's the same with ultrasound

in a lot of cases on a static image.

If there's no pathology,

they don't make themselves very discernible.

But I will say ultrasound has the advantage

in that we get to make the tissues move,

and those movements can oppose the surrounding tissues.

And that's what we're seeing here.

We're seeing the bulk of the navicular shadow over here

pushing that posterior tibialis tendon

and the tibionavicular ligament complex.

All of this up here is moving separate from the spring.

So we can see the spring ligament.

We're relatively cross-section to the spring ligament here.

And you can see that insertion

to the spring complex of the tibiospring.

So tibiospring sandwiched between these two other ligaments

that are not the star of the slide here.

But that's one way, a very useful way,

to evaluate tibiospring

if it's something that you're working on.

Next is the tibionavicular.

So this one is, I would say the more challenging

of the deltoid ligament complex to see

because it's so thin.

I typically don't focus on it.

I will admit I sometimes even skip it

if I don't have anything to look at in that area.

I'm basically windshield wipering

all the way acrossed this portion

and doing those dynamic maneuvers.

And if I don't notice anything anterior

to that tibiospring area,

then I really don't go much further anterior

if there's no reason to.

But just for the sake of being thorough,

let's go ahead and show you

what that looks like on the slides.

So if you did see tibiospring in the last slide

and you did see the shadow of the navicular

starting to come into play,

we were already climbing into the tibionavicular portion,

which is extremely thin, hard to see.

And you can rock your transducer around

and get this fat to move on top.

That's one way to kind of see

what the superficial aspect of it might look like.

And then deep to that, you know,

we're invading that tibiotalar,

deep tibiotalar ligament area here on the talus.

So that's one way to kind of find out

what's on top and bottom of it.

But I don't take an incredible amount of time

looking for this one.

If there's nothing wrong in the area,

there's really nothing to stop

and beat your head over about.

So just kind of move along what looks like a fascial plane

abridging the tibia to the navicular.

And then the most anterior one,

which we had covered earlier when we were sweeping through,

was the tibiotalar ligament.

And we'll cover it further

in the live demo for the sake of time.

So with that, I'm going to switch over to the studio

and get us set up for the live demo.

All right, so we'll start with the live demo.

But before we get started,

I want to discuss the transducer options here.

The main transducer we're probably going to use the most

is the L15-4.

That is a 15 megahertz to 4 megahertz range.

We're very shallow

but the length of the transducer is very handy

with the long axis of these tendons

and even that ankle ligaments in some areas

like the anterior tibionavicular portion

is particularly long.

So the long footprint's

very advantageous here in some cases.

Other cases we're going to get around the bonier malleolus

by switching over to the L19-5 transducer.

So that's a 19 megahertz top end frequency,

but its small footprint is very advantageous

around the malleolus.

And we typically run out of gel contact

right here around that part right at the malleolus.

So I'll just kind of show you what I'm talking about.

There's typically an air gap

with the larger linear array transducer.

So when we do that,

here we get a big air gap around the malleolus.

And instead of always filling in with more gel,

switching over to the smaller footprint

19-5 megahertz transducer is very nice.

And then I like the traditional handle of the 19-5

rather than a hockey stick

for long to short axis scanning.

Very easy to segue back and forth

for diagnostic and interventional procedures.

But we'll start with the 15-4.

which is what's hooked up.

I'm going to grab some ultrasound gel here,

and we'll get started.

We're going to work our way from deep to superficial,

just like in the PowerPoint.

So again, we're going to start on the bony landmarks

and then the ligament evaluation,

working our way up to the tendons

and then the neurovascular structures.

So I'd like to wrap arm around the cord

and get a lot of this cord out of the way.

I do palpate the malleolus while I scan a lot of these.

I am going to keep the left side of the screen anterior,

just to keep it consistent with the slides.

And I like to start on the backside of the malleolus

in a relative cross section.

All right, so left side of the screen,

let me get my arrow up and going.

We've got the medial malleolus.

Okay, let's fall off that

and look for the next cortical landmark

posterior to the medial malleolus.

Here's the talus.

So as I swept and windshield wipered

the transducer proximally more axial,

that is just tibia.

So this is all tibia.

And then as I go distally, distally, distally,

let's fall off of the medial malleolus of the tibia.

The next bone here is the talus.

And then if I keep climbing distally,

we'll encounter another joint back here.

And then the neck of the calcaneus,

just to give you an idea.

That was all axial scanning there.

And if I go long axis scanning on the tibia,

I see the distal portion of the tibia,

the medial malleolus of the tibia.

And then if I fall off, there we go,

here's talus again.

So tibiotalar.

And then there's a joint that we see here,

and then we start to see the calcaneus come in.

And if I sweep the probe this way now,

distal side of the probe,

right side of the screen more posterior,

we elongate that neck of the calcaneus,

again, as another reference point.

So just kind of getting those bony joints roadmapped out.

Let's go anterior with this just a little bit.

So as we looked at the ligaments on the anterior side,

anterior superficial deltoid,

which would be the tibiotalar,

here's our distal malleolus again.

And then you can see where that bony interface

causes the air gap there.

So we're going to add a bead of gel right there

where I saw my transducer let up pressure,

which is another tip you can do.

If you don't see all of your scanning landmarks

while you're scanning,

because of an air gap like that,

you can give it a little bit of pressure

on the sides that you are getting image,

and then when you let up,

you're left with this rectangle,

and that'll be a good spot

to lay down a bead of gel right on the rectangle.

That way, you end up with a really nice gel standoff,

like we have here.

So medial malleolus, anterior talus

with a little bit of the cartilage,

and then the navicular starts over.

That's probably the medial most cuneiform there.

Navicular would be just a bit more medial.

There we go.

So talus, navicular,

just to introduce those bones as we scan.

So now that we have the bones oriented,

especially the talus, that's going to be a big landmark here.

You can see that big cartilaginous interface

of the talus' articulating surface with the navicular here.

We'll climb back up on the medial malleolus.

and start scanning some of these ligaments.

I think this first ligament is the easiest one to scan.

It's a deep deltoid ligament.

It is posterior.

When the ankle is relaxed like this,

it's difficult to see.

The ligament's tucked up under the malleolus,

and it's very hard to see.

So we're going to fall off the medial malleolus just enough

to where I start seeing that shadow.

And then I've got the talus in orientation here.

And what I'm going to do is just have our patient dorsiflex,

and that brings that deeper deltoid ligament out.

So this is our posterior tibiocalcaneal,

or, sorry, tibiotalar ligament.

And it is a deep ligament here.

And then keeping that same dorsiflexion going,

I'm just going to pivot all the way around

until I see the anterior.

Let's go ahead and drop the front of the foot

until we see that deep deltoid ligament

of the anterior tibiotalar ligament.

And so I should see a little bit of a portion

of the the anterior talar cartilage,

like we did on the anterior ankle where we saw the ATFL.

Well, this will be the

anterior tibiotalar right here.

So we can see that deep ligament here.

I'm just going to stress the ankle just a little bit more,

just to see that deeper deltoid shadow

right where my arrow is.

There, right under there.

And actually, what I'm going to do is push down with my palm.

You can see my palm down here on the foot.

And provide just a little bit of stress.

So there I'm just kind of pushing down.

And what I want to do is show these soft tissues up here.

Some of this is fat.

There we go.

And I'm trying to find and delineate that shadow

of that deeper ligament layer right here.

So this deep shadow diving

is an anisotropic shadow

of that anterior tibiotalar ligament.

Here's the cartilage of the talus.

Nothing's attaching there.

And then there's a little bump, little tubercle there,

and that would be where it inserts.

So that takes care of the deep layers

of the deltoid ligament.

Let's go to the superficial layers.

So back up to the medial malleolus relatively posterior.

It's not going to be superficial

to that first easy ligament, not necessarily,

but we're going to follow it and use it as a roadmap.

So here's our medial malleolus, here's our talus.

Now we're looking for the portion that jumps over the talus

to the calcaneus portion.

So this is the sustentaculum tali of the calcaneus.

And just to check our work on that,

it looks like another medial malleolus.

That's one way to kind of distinguish it.

Number two, we'll get to the FHL.

The flexor hallucis longus sits on this neck.

And I'm just going to wiggle the big toe.

So when I see that landmark right here,

I know to abridge these two.

So medial malleolus, sustentaculum tali.

And we should get that superficial tibiocalcaneus,

or, sorry, tibiocalcaneal portion

of the superficial deltoid complex here.

Really nice fibers.

Sometimes inverting dorsiflexion

just to delineate these layers.

So what I'm going to do is use my hand over here,

and I just want to see this layer move

relative to the tissues around it.

Not much.

Again, there's not anything wrong with this ankle

and its ligaments,

so we're not going to find a lot of distinguishing layers

until there's actually acute injury or even chronic injury.

Let's move on to the...

Let's introduce the spring ligament really quick

because it is our landmark for the tibiospring.

So if I'm scanning posteriorly here

and I find that

sustentaculum tali of the calcaneus right there.

So you can see that big bony neck on the calcaneus portion.

And what I'm going to do is plant that portion

of my transducer, okay?

So that is the smooth side of the transducer,

or the right side of the screen.

I'm going to plant that part.

And now I'm going to windshield wiper

and swing the dot side of the probe,

which is this part here,

with the orientation marker.

We're going to drop that down.

And we should see...

There we go.

See the cartilage of the talus?

That's one landmark.

We're almost there.

So here's the cartilage of the talus.

And I'm going to fall down just another bony landmark,

and that should be the navicular.

And so here's the navicular,

here's the sustentaculum tali of the calcaneus,

and that's where we start to see this ligament complex

creating this nice hammock.

It's an upside-down hammock, basically.

So it's not supporting the structure superficial to it

as much as it is holding with, you know...

If the foot were load-bearing,

this talar cartilage, this whole interface,

would be pushing down on the spring ligament here.

And the spring ligament's very important

to go ahead and map out

because superficial to that,

there's a ligament complex attaching to it in transverse.

So we see this transverse

kind of oval egg-looking structure,

and that is the tibio, tibiospring ligament portion

of the superficial deltoid complex.

And we're going to trace that proximally

up to the malleolus in long axis.

So I'm going to spin this transducer

around this ligament portion.

It's the only, the tibiospring is the only ligament portion

that attaches to a ligament

instead of a bone in this part of the ankle.

So let's follow that anisotropic shadow.

So just superficial to it as a landmark is the PTT,

the posterior tibialis tendon that we'll get to.

Underneath that, that really dense anisotropic area here

is the tibiospring

as it heads up towards the medial malleolus.

There we go.

So here you can see the fiber's very, very shallow.

Some of them are diving and fanning out.

It is a pretty broad ligament,

and you can start to see them attaching into this complex.

And all this area here is that complex

that we just looked at.

The cartilage of the talus down here

being another good landmark.

So tibiospring ligament here,

PTT or tibialis posterior right here.

So there they are just bordering each other.

And then the next one, the most difficult one to scan.

And I honestly don't spend hardly any time

looking for this one unless there's a injury here.

So if we don't see it with confidence here today,

don't stress too much about it.

But we're going to go to the anterior part

of the medial malleolus.

Okay, we're going to bridge all that gel over to the navicular.

So we see the navicular here and the talus here.

And what I'm looking for are...

And I'm pushing down with my palm,

so I'm going to push down and stretch this ligament

as much as I can.

And one of my goals here is to distinguish tissue movement,

stationary tissues

to tissues that are moving while I scan.

So it's just another tool in your toolbox

to add dynamic maneuvers

and try to get these tissues to move acrossed each other.

And when in doubt, just keep adding gel,

and then the image just gets better

and better and better, right?

All right, so medial malleolus

following the superficial fibers.

So this is the tibialis posterior tendon.

So I've gone too far posterior.

Now I'm going to move anterior to that.

So right there on that anterior

kind of facet of the medial malleolus.

Once I see some anechoic anisotropic fibers

trying to attach there,

I'm going to windshield wiper the distal portion

up and over this talus neck as much as I can

to the navicular portion

until I see some fibers distinguish themselves.

And there's no injury here.

Again, it's hard to see this particular ligament.

And most of the references out there

just kind of skip over it in their ultrasound exam.

So don't get discouraged

if it doesn't just hop right out at you.

But here you can see the connective tissues

moving over this cartilage of the talus.

So watch this band as it hugs the talus

and slides up and over the cartilage portion

over to the navicular.

We're going to look at the tissue movement here

when I push down on that first metatarsal right there.

So that is about as good amount of movement

as I can get the ligament to show itself.

It's just not super thick, it is more broad than thick,

which leads me to tell you

it's much more easy to discern each of the ligament layers

from the anterior most surface

of the medial malleolus right up here.

Follow the shadow right here.

So we're cross-section to the medial malleolus,

and we're going to fall off the medial malleolus distally.

So medial malleolus, let's fall off of it,

and let's use the anisotropic shadows

of the deltoid ligament complex to our advantage.

So I'm just teetering the probe

distal proximal, distal proximal

in probably 1/2-centimeter increments.

And I'm looking for volume loss,

I'm looking for herniating tissues,

I'm looking for the anisotropic artifact that we see here

of the deeper portion of the deltoid complex

and the superficial portion of the deltoid complex.

To discern which is which,

here's the anterior part of the medial malleolus.

So that would be the tibionavicular portion.

The middle section.

We're going to fall down into tibiospring right in here.

And then the posterior portion of that

is that bigger tibiocalcaneal portion,

which is the biggest, strongest one,

easiest to see.

And then the deeper layers under here

show up better when we have dorsiflexion.

So if I had our patient dorsiflex, those will tighten up,

and they're almost relatively horizontal

to the backside of the ankle, anyways,

which I've got my transducer flipped from earlier.

There.

So, way easier to see that posterior tibiotalar

in dorsiflexion,

and the anterior tibiotalar in plantar flexion.

There.

But it's this whole complex.

Stay hugged around the medial malleolus, scanning like this,

and then also check and cross section as often as you can.

So we'll start now on the tendons of the medial ankle

and get back to the live scan.

All right, so here we are back to the slides.

Medial ankle tendons are next.

And thankfully, I will say this is easier.

The deltoid ligament complex is the most difficult thing.

Sorry to throw you into that head first,

but anytime you're scanning something new

in musculoskeletal ultrasound,

you should work your way from the bones

and work your way superficially into these soft tissues.

These are the most variable items that you're going to scan,

are the superficial soft tissue structures,

like ligaments, like tendons, tenosynovitis,

synovial sheaths, and the surrounding fat.

So let's dive into the tendons.

Much easier to look at when you are scanning these

if you start at the malleolar level in cross section.

They all line up very nicely.

And I mentioned that in the last webinar,

and the anterior ankle in particular,

that if we're scanning all these crazy tendons in the ankle

and you start in your cross-section,

and at the mid-malleolar level,

it's very simple to to just pan your transducer

distal proximal, distal proximal

and see these structures stay in the center of the screen

before they start going off their various directions.

So we're going to focus on the medial malleolus first

and then work our way posteriorly

out into these soft tissues.

So this is the tibialis posterior,

also called the posterior tibialis tendon.

In all the references, you'll see it called the PTT.

So that is the posterior tibialis tendon.

Bordering it in parallel at the malleolar level

is the flexor digitorum longus.

It has a longus way to go.

It does actually traverse this canal under here,

some soft tissue landmarks that we'll talk about

called the knot of Henry,

before it takes its immediate turnout

to the digits on the bottom of the foot.

But it does run in parallel

to the posterior tibialis tendon at the malleolar level.

And then from there, it's easy to trace.

It does have a more distal musculotendinous junction

than the posterior tibialis tendon,

so that's also helpful.

And then its neighbor just immediately posterior

and relatively parallel at the malleolar level

is the flexor hallucis longus tendon.

And as I mentioned before,

anything with the word hallucis means big toe.

So this is the flexor for the big toe,

and it does have the most distal musculotendinous junction.

And if you're dealing with an athlete or a runner,

don't be surprised if you see that muscle

coming all the way down into that tarsal tunnel area,

causing some issues.

Some overdevelopment might cause crowding.

Tenosynovitis, swelling, ganglions

may also cause crowding in this area.

And so you can end up with some FHL tendon sheath issues,

as it has its own tunnel here,

and we'll show that on one of the slides.

But flexor hallucis longus is this guy here.

Also called, and I didn't put this in the slide,

and I should,

but a way to remember this from medial

or malleolar level and posterior

would be Tom, Dick, and Harry.

So that's one way people will remember this..

Not a subject of today,

it's just something else that your transducer's

going to lay across.

So if your probe is over here at the malleolar level

and you're slicing the ankle transversely,

there are our subjects here

on the left side of your screen typically,

but the right side of your image

is just going to be all this wavy soft tissue stuff.

And that's typically Kager fat pad.

And then you might see an anisotropic oval

on the far side of your screen,

and that's the achilles tendon.

So just be aware of that.

It's not the focus of today, but it will be in the image.

So here we have that slice that I mentioned,

starting at the malleolar level.

So medial malleolus,

we see the posterior tibialis tendon,

flexor digitorum longus.

And then we're not going to focus on these other guys,

they're not a part of the tendons.

But here is the musculotendinous portion

of your flexor hallucis longus right here.

We're going to work our way

to long axis of each of these structures,

and you can see the reference of that same axial slice

or that same transverse slice down here.

Notice the angle the transducer should go.

I don't want you to go 90 degrees to the skin here,

I want you to lean the probe,

I want you to lean the probe handle towards the achilles.

And that will allow you

this nice bony backboard of reference.

If you only take a 90-degree slice here,

even though it looks like you're going to have

a nice bony reference,

because of the shape of the tibia,

you're only going to catch part of the malleolus,

and the rest of the tendon

will be floating out in soft tissue.

So it's not much of a reference point

of the bony acoustic landmarks in the area

if you just take a 90-degree slice

from the skin down to the malleolus.

I want you to lean the transducer more towards the achilles

and then fall off the malleolus posteriorly.

And I'll elaborate that on the live scan,

but here's our relative transducer angle.

Here's the tendon that we were talking about.

Deep to that after this,

this tendon jumps off the malleolus.

This is part of that deltoid ligament complex.

Now, you're familiar with those soft tissues.

It's not a mystery anymore of what we're seeing down here.

And sometimes those layers are degenerated

and have a more laminar look.

And now you know you can move the ankle around

and kind of see the differences between those

and if they're an issue or not.

But I have seen ligament,

old degeneration look like some sort of synovitis

because it was anisotropic in some cases

and not anisotropic in other slices.

And it looked like some proliferative synovitis

coming out of the tibiotalar joint.

But what it really most likely is,

is the degenerated ligament layers

making things look like they're coming from the joint.

All right, so distal to the malleolus,

now we're traversing towards the insertion.

The neck of the tail is a great landmark to follow this.

But here's your tibialis posterior tendon.

And the shadow of the navicular is out here.

But the dynamic maneuver is the way to go.

If all this looks ambiguous

on the patient that you're scanning, not our patient today,

it'll be very easy to see.

But the patient you're scanning,

if all these tissues are blending together

because they have a very degenerative ankle

and the tissues just don't look right,

then, you know, we're using ultrasound.

So we're going to make it move.

And I want you to do inversion of the foot

and make that navicular move.

So we'll do this in the live study,

but you can see how the navicular

pulls the posterior tibialis tendon here.

And it's very fan-shaped.

And it has a very anisotropic

deep tissue characteristic here

because a lot of these fibers

hammock underneath the navicular,

much like the spring ligament would, as well.

So they fan shape around the navicular.

I've heard it described as a snake eating an egg

at this point right here

where you can see all these fan-shaped fibers.

But make the tissues move,

and that'll be the best way to get around these tendons.

Next, immediately posterior to that.

So go back up to your posterior tibialis tendon

and then just translate the transducer

exactly in parallel fashion posteriorly,

and you'll catch the flexor digitorum longus.

And then just wiggle the rest of the digits, the toes,

the smaller toes, to make this tendon isolate itself.

Medial malleolus, talus is coming into the view.

Let's go distally and see what happens

after the medial malleolar level,

'cause that's when I said all these tendons

go their different directions.

Again, wiggle the little toes,

and we'll do that in a live study.

But what looks like a bunch of weird synovitis

and junk out here

is really just those transverse views

of the deltoid ligament complex.

And we don't want to call any of this fluid

or any ratty tissue disruption

until we dynamically take a look at the deltoids.

Even more posterior in the same parallel fashion.

So you can see now we're wrapping our transducer

more posterior in the ankle in this axial slice.

And you can see how far back we're going.

We're leaning the transducer very much against the achilles

for this particular image.

So if you want to get a really nice picture

with a bony backboard of your cortical landmarks

of the posterior malleolus of the tibia, the talus,

and the calcaneus all in one shot,

and here's your subtalar joint,

that's how you do it.

You just lay the transducer towards the achilles

and then refine your skeletal reference points first.

And then let's wiggle the big toe.

So we're just going to pull the big toe,

and you can see that distal musculotendinous junction

just pull its way through its own tunnel.

There's an osteofibrous tunnel

just above the subtalar joint.

But here's your subtalar joint posteriorly.

Here's the flexor hallucis longus.

And I'm just moving the big toe.

Again, hallucis means big toe.

And that queues us up for the live demo

for the medial ankle tendons.

Just give me a second while I fire up the studio,

and we'll do this live.

Okay, so we're back at the medial ankle.

We're going to start scanning for the tendons,

which is easier than doing the ligaments.

But we're working our way from the deep cortical structures

in most of musculoskeletal ultrasound,

and we're going to work our way more superficially.

So I'm going to start on that medial malleolus again.

Screen left is towards the medial malleolus.

Very easy landmark to see.

And this is definitely something that is easier to see

on the 19 megahertz transducer, as well.

But let's point out the anatomy

and this wide field of view that we have.

So here's the tibialis posterior, this oval,

it's the larger oval.

It does have a neighbor here.

This is the flexor digitorum longus, okay?

And then they border each other.

They pretty much touch each other right there.

And then a little bit further back in the image,

we can see the neurovascular structures,

which we'll focus on here momentarily.

But then we see this large muscle mass

headed towards the Achilles.

So all of this down here is the Kager's fat complex.

Here's the achilles tendon itself.

So you see that in the anatomy slides, right?

So here's Achilles, here's Kager's,

and then here's, bordering that is our FHL,

or flexor hallucis longus muscle belly,

which travels much more distal.

And let's follow that until it tapers to a close.

So the musculotendinous portion was right here.

Don't confuse this far distal muscle belly

for a tenosynovitis.

For one, we can go long axis on that and see if it moves.

So starting on that.

Let's watch 'em all move real quick.

So in long axis, we'll start on the medial malleolus.

And I don't see any tendons here.

And then we're going to fall off

of the long axis medial malleolus.

We're going to fall off of that posteriorly.

We're going to keep our probe parallel to the medial malleolus.

So the first tendon we encounter superficially up here,

this is the tibialis posterior.

And distal to the malleolus

is when the tendons start going their different directions.

We talked a little bit about that

in the anterior ankle exam,

but same thing applies for the medial and the lateral exam,

is that once we are proximal to the medial malleolus,

we really don't have to move our transducer that much.

But once we go distal to the medial malleolus,

that's when they all start heading

their different directions to their insertions.

But let's scan this tibialis posterior here.

If we wanted to move it, that'd be inversion.

Getting the navicular to move basically.

So you can see the tendon

on the far right side of the screen tenting up

as it is less taut.

All right, so now I'm going to fall posterior

to the tibialis posterior tendon.

Just immediately posterior to that,

there's another tendon right here.

And just to double-check our work

that this is the flexor digitorum longus,

which we know goes to the digits,

I'm just going to wiggle, passively, the toes.

So I'm just going to go start on the second toe,

third, fourth, fifth,

and just make sure that's the tendon group

that we're looking for here.

So landmarks underneath that are the tibia, talus.

We start to see a little bit of the shadow

of the calcaneus coming into view.

Now, posterior to that running parallel,

neurovascular structures are going to come into play.

That's fine.

But let's go find that sustentaculum tali of the calcaneus.

So this is your posterior subtalar joint

to the calcaneus.

And that tells me that we're almost there

to see the FHL in motion here.

So let's get a long axis FHL.

And you can see the joint.

Here's your posterior subtalar joint right here,

which does, in some cases,

communicate with the tendon sheath of the FHL.

So you can have a joint effusion

outwardly pour its fluid

into this tendon sheath in some cases,

so keep that in mind.

And let's watch this tendon.

I'm going to move the big toe, just passively.

So flexor hallucis longus,

I don't know that I mentioned it in the slides,

but hallucis means big toe.

Very easy to see it move.

But you can see that distal musculotendinous portion

try to pull its way down into its own little tunnel.

And you just don't want to call that tenosynovitis.

You don't want to call it a joint effusion.

If you're holding real still,

and on a lesser quality ultrasound machine,

it may appear that this is all fluid, and not muscle.

See if that fluid moves with the big toe tendon, right?

And if that does move with the tendon,

then it's probably just the distal musculotendinous portion.

All right, so, what happens after the malleolar level?

Let's go chase those down.

I'm going to move all my gel heap around.

After the medial malleolus,

okay, the tibialis posterior looks,

it really looks the most complete here.

So we see this very broad tendon take a fan shape

grab at the navicular.

So it doesn't just attach to the navicular,

it envelops the navicular.

And here we can see a couple branches of that tendon.

The deeper branches are going to go underneath the navicular

and head all the way over to the undersurface

of the medial most cuneiform.

And then these medial fibers,

they're going to wrap around,

kind of like a snake eating an egg,

around the navicular.

So this is navicular.

Here's the talus.

And I can just cause a little bit of

motion to that tendon.

Can loosen the tendon passively

and see if any fluid bunches up into those tendonous fibers.

But that's one way to do a dynamic exam,

is just to lift the navicular

with the first metatarsal, basically.

So that's the long axis.

I'm going to go short axis there,

starting at the navicular.

So this is all navicular.

And here's the undersurface of the navicular

where we catch the majority

of that tibialis posterior tendon.

So tibialis posterior tendon is this big oval here.

This the undersurface of the navicular.

So when I see a big cartilage interface like this,

that's talus.

And then this is spring ligament right here.

And then this is the tibial posterior tendon

and cross-section.

So just to check our work there,

we're just going to creep up towards the medial malleolus

in little one-centimeter increments.

We're just going to walk back forth, back forth.

And we're going to watch this tendon as it ovals out

and it's resting on top of the ligament complex

that we just scanned, like a hammock.

And we're just going to keep following it,

keep following it, keep following it.

There we are, back at the medial malleolus.

And then its neighbor was the flexor digitorum longus.

I apologize, I did flip the probe.

Bad habit.

So we'll go back down just to check our work again

and follow it to the...

We already did the hard part, right?

And that was the ligaments underneath it.

So here's the navicular.

And then we can see the tibialis posterior here.

And you see two ovals here, right here, here, and here.

One of those is spring ligament, which is over here.

And then here was that tibialis posterior.

So following that, following that, here we go.

All right, and what just came on top

of the sustentaculum tali right there?

That's not the nerve,

that's the flexor digitorum longus just moving,

which is neat because you can also see

quadratus plantae down here moving with the tendons

because it's just leaving

the medial aspect of the calcaneus.

Okay?

Back up to the navicular, so,

or sorry, medial malleolus.

So medial malleolus, flexor digitorum longus.

Let's focus on that one.

Flexor digitorum longus goes on top

of that sustentaculum tali you can use.

If you lose it, we can use the anisotropic artifact

to our advantage right there.

So here it is cut at 90 degrees.

Here it is with the anisotropy.

We'll go distal and just follow that shadow right here.

And this is probably far enough

if you're not anticipating pathology

distal to the knot of Henry,

which we'll talk about

right now.

So back up to the sustentaculum tali of the calcaneus.

So sustentaculum tali right there

looks like another medial malleolus.

Here's the FHL posteriorly to it.

So I'm just going to passively wiggle the big toe

and check my work.

And we're going to follow that wiggling FHL

as it meets up with the FDL, flexor digitorum longus.

And here they become neighbors,

and they're touching right there.

And right here where we see the FHL

try to pass under the FDL,

this landmark, this area right here where they,

it's like if you crossed your fingers,

like I'm doing here in the video,

that little landmark is called the knot of Henry.

And that's another area to look for an abrasive pathology

where these two tendons can rub on each other

and cause a lot of pain in the arch of the foot.

And that's right here.

It kind of looks like a yin yang sign

when you cut it at the right angle.

So you can see those two tendons

use anisotropic artifact to your advantage.

If you want to isolate these two tendons also,

just passively move the toes,

so little toes

and then the big toe.

But that's the knot of Henry.

If there's any reason to go distal to that,

just keep following each one of those individually.

But it's very rare

that we need to follow the FHL distally for example.

It's very rare that we need to follow the FDL

to its enthesis all the way at the digits.

So Knot of Henry is typically a spot

where we stop scanning for those tendons.

But that about covers the tendons.

We don't see the tendon sheaths very well

unless there's pathology,

except for around the tibialis posterior.

So I'll switch over to the 19 megahertz transducer,

and we'll show you the tendon sheath

of the tibialis posterior.

So here's tibialis posterior.

Bring up my depth, grab my arrow back.

Much higher resolution.

We can actually see the flexor retinaculum,

which will be covered in the tarsal tunnel.

But flexor retinaculum,

tibialis posterior, flexor digitorum longus,

neurovascular structures, which we'll chase down later.

And then here's the FHL

just posterior to that sustentaculum tali calcaneus.

I flipped my orientation again, sorry about that.

So tibialis posterior, FDL,

and then you can see that really, really nice FHL.

And then let's go look at the tendon sheath of the PTT.

Right there, you can see a normal synovial slip right there,

that little anechoic area.

And if I grab the big toe and metatarsal

and invert the foot a little bit,

will typically cause a pooling of fluid

around the tibialis posterior,

if you just wanted to see that tendon sheath.

But right there in that corner, that's normal.

Don't call it abnormal unless it envelops the tendon.

So I would see, circumferentially,

I would see fluid all the way around the tendon

if there was something wrong with it.

And then let's just take a look at these ligaments

while we're here with the 19 megahertz

since we didn't do that last.

So here was that posterior tibiotalar portion.

We're going to dorsiflex the foot

and look at those ligaments really nice,

very, very high res.

I mean, we're seeing so many fibers,

this broad area right here

all the way down to the talus at this point.

Now let's move on over to tibiocalcaneal.

So we need to see that sustentaculum tali, which is here.

A little smaller field of view.

So seeing the broad ligament

all in one shot's not going to happen,

so it's really important that you keep a bone in view.

So here, immediately, here's the malleolus,

superficial layer, deep layer.

Just kind of keep that in your mind.

The deep layer is going to the talus, superficial layers.

For the most part, all go into the calcaneus

or the tibiospring.

And here's that tibiospring complex underneath the PTT.

So here's the PTT that we just looked at,

the posterior tibialis tendon,

and here's that tibiospring portion just underneath it.

All right, so, great advantages

to using a 19 megahertz transducer.

Far more detail.

The frame rates are actually a little bit more live.

So if you're looking at popping, clicking, snapping,

this transducer catches those in real time.

Very, very nice.

And procedurally, it's a lot less transducer in your way

when it comes to doing injections around the foot and ankle.

So this probe is very nice long.

Axis to short axis scanning.

As you can see, I'm not having to move very much.

For example, to do a long axis

and short axis scan of my flexor digitorum longus,

it's just moving the fingers,

and not your whole hand, as in a hockey stick.

But that takes care of the tendons.

We'll go back to the talk,

introduce our tarsal tunnel,

and then come back to the live scan.

All right, so to the tarsal tunnel now.

We'll skate through these,

'cause all the imaging planes have already been covered

and it's pretty quick

to show you the neurovascular structures.

So first thing we're going to focus on is this guy,

the elephant in the room, the tibial nerve.

And the tibial nerve branches off

and it has a medial and lateral calcaneal branch

at the level of the tarsal tunnel.

Where it bifurcates is pretty variable.

So you want to start scanning these pretty high

and look for those little bifurcations,

or they can get away from you.

And then posteriorly, you will see a guy skate over

towards the calcaneal neck,

and that's the calcaneal branch.

Our roadmap for all nerves is going to be arteries.

So if you can't find the nerve,

come on up more proximally again

and look at the artery first as your roadmap.

Veins will follow.

Chances are, if you're scanning anything in this area,

you're applying a fair amount of pressure

because of that big air gap

that shows up when we scan the medial ankle.

So your pressure will probably collapse the veins.

So be aware that we need to add a significant gel heap here

to show that we're not collapsing things

like a big joint effusion.

Tenosynovitis of the flexor hallucis longus, for example,

is very common in the tarsal tunnel as a choking point here.

So the veins can be a good marker

of how much transducer pressure you're applying.

If you're evaluating somebody else's ultrasound images,

look and see if you can find patent veins.

And if you don't see veins in the shot,

chances are they're applying too much probe pressure.

Then, lastly, we have this flexor retinaculum

from the tibia to the calcaneus,

and that's our proper tarsal tunnel.

But it's all these other factors,

like the tendons, the joints, that can have ganglion cysts.

Space-occupying masses, like loose, bony fragments,

can occur in these areas.

So if you're not seeing nerve diameter changes,

one thing to look for are ossifications in the ankle,

old scar tissue that is calcified

and clinging itself to the nerve

against the flexor hallucis longus tendon, for example,

or flexor digitorum rarely.

I don't see the nerve branches

resting up against flexor digitorum necessarily

as much as I do flexor hallucis longus.

But right here at that retinaculum

is the typical choking point.

To get a really nice image of the anatomy,

you start more proximal.

So you're only going to catch a little bit

of retinaculum at first.

So if we're up high on the tarsal tunnel at the inlet,

we'll see a really nice flexor retinaculum first,

but it'll taper off to nothing

because we're really obliquely slicing the retinaculum.

But it does give us a nice starting point

for our tarsal tunnel here.

So tibialis posterior, flexor digitorum longus.

And now we can talk about the neurovascular structures,

like the little arteries and the nerves.

At this point, it's still laying as one nerve,

but I will say that those branches

are ready to start splitting.

So we'll move the transducer distally

into the proper tarsal tunnel,

and the anatomy and the landscape

and everything starts to change.

So it's not just tibia anymore,

you're going to see a lot of talus

after you leave the the tibia

and you rest the transducer off the neck of the calcaneus.

You're going to see a lot more bony acoustic landmarks

be more pronounced right here,

like the sustentaculum tali.

It's a huge landmark.

We need to wiggle the FHL, move the big toe,

and show where you are.

But this looks a lot like a medial malleolus.

And you don't want to call that a medial malleolus

because we have a lot more tissue up here.

And just to give you some closure

on what else is happening over here,

we have the superficial deltoid ligament

at the sustentaculum tali area.

We know at the talus area, this far posterior,

these are cross sections, most likely,

of our posterior deep tibiotalar ligament complex.

So there's a deep and superficial

inserting somewhere over here.

But superficial to that,

we have a tibiocalcaneal ligament that was the big guy.

And then we have the posterior tibialis tendon.

Superficial to that, flexor digitorum longus.

Superficial to the sustentaculum tali of the calcaneus.

And that landmark acts as this pivot point

for the FHL to wrap around

and make this turn with this bony acoustic backboard

to provide that leverage that it takes to turn a corner.

So it has its own tunnel.

And you'll see another little fascial osteofibrous tunnel

for the FHL to rest in.

And then back here even further, you'll see a muscle

that's starting on the medial neck of the calcaneus,

which we brushed on briefly

on the plantar fascia portion of the last webinar.

But that is our quadratus plantae muscle origin

on the medial neck of the calcaneus there.

All those little soft tissues that are there,

we're really just focusing on what's happening with the FHL

and the space that is created by this wedge

underneath the flexor retinaculum

above the FHL

and kind of posterior

to the sustentaculum tali of the calcaneus.

So we're just going to swing the probe from proximal to distal.

We're going to wiggle the big toe

so you can see that shadow

right up against the neck of that sustentaculum tali,

and start moving the big toe.

And we'll do that in the live scan.

It'll look much like this because it's the same model.

And then all this soft tissue out here,

this is the muscle we discussed over here,

the quadratus plantae,

along with the neurovascular structures.

Again, I don't have a color doppler shot on this,

but we'll do it in the live study.

And then we already went over the soft tissues over here.

You can see that.

Now that you know what ligaments look like in the ankle,

you know that's not tibialis posterior right here.

You know this is tibialis posterior.

You know horizontal acting like a sling underneath that

is one of your deltoid ligaments.

So it's nice to have that confidence

of what's enveloping the joint before we hit our tendons

when you're evaluating the ankle.

Let's move over to the live demo.

And after the live demo will be our time for live Q&A,

so have your questions ready.

As we do the live demo,

start getting those typed up into the chat portal

of the question and answer portal on Zoom.

But let's switch over to the live scan and get going.

All right, so we'll get back onto

the 15-4 megahertz transducer and to the tarsal tunnel.

Screen left would be the malleolar side again.

So I'll get my arrow back up here.

And let's just start with the easy structures to see,

which are the arteries and the veins, superficially.

We're going to throw on the color

and see what that blood flow is doing.

If you're not seeing these little veins fill,

you're either pressing down too much

and you're just seeing an artery,

your color flow settings

could not be set for sensitive enough,

or you just need to augment the tissue distal to the vein.

So you can see I'm just pushing down distal

and just working the blood flow up proximally

as those veins drain back up towards our heart.

And you can do that with the ultrasound.

So if you're ever in doubt

with the structures that we're scanning,

just throw the color on and use it as a roadmap.

But as you see me working proximally,

this posterior tibial artery will follow the tibial nerve

until it branches into three parts.

So we should see the calcaneal branch kick off first

and head posteriorly.

And we could see the medial and lateral plantar nerves

jump off of it here.

So following that distally to the sustentaculum tali,

that's where we see the two divisions of the nerve

for the medial and lateral plantar very nicely.

And then we'll switch over to the 19 megahertz

and really get a good evaluation on these.

But what's nice about the larger field of view

is I can see the medial, lateral.

And I thought I had the calcaneal portion in here,

but I lost it.

But we're going to focus on these two here

at the 19 megaherz exam.

So switching over to 19.

Back up to the malleolus.

And you can see that we're going to get a lot more definition,

a lot more nerve detail with the 19 megahertz transducer.

Going to bring my depth up more shallow.

And now let's follow these (indistinct)

and see if there's anything inside the nerves

that we notice could be contributing to any issues.

So I look for nerve swelling,

I look for space-occupying masses, calcium deposits,

old, bony fragments in the tarsal tunnel.

But especially here, the FHL level

where the sustentaculum tali of the calcaneus

is with the FHL,

this little tunnel here is where we see a big effusion

will collect and push into the nerves

at this level of the tarsal tunnel.

So tarsal tunnel level is defined

at the level of the flexor retinaculum,

which is this guy, superficially.

Let's follow it over.

So here's flexor digitorum longus.

Here's the posterior tibial tendon.

And then here I can see the flexor retinaculum

originate on the medial malleolus.

This triangular dark wedge,

that's our flexor digitorum longus,

or, sorry, that's our flexor retinaculum.

And we're going to follow that distally

towards the neck of the calcaneus

and just kind of delineate where our tarsal tunnel is.

So we can see that little thin, thin line.

It helps to move dynamically,

but we can see that thin line of the flexor retinaculum.

I'm going to keep my finger down on the calcaneus.

There we go.

So calcaneus, here we are.

And here's that flexor retinaculum diving down

to just about to the tubercle level of the calcaneus.

But just deep to that

is our quadratus plante muscle down here.

And you can see these fibers

climbing about that level of its origin, I would say.

And here we can see the calcaneal branch

already starting to kick away.

And then we still have the medial

and lateral plantar nerves.

Let's go down in depth a little bit,

turn our gain up a little bit

and follow, keep following the nerves.

But that was, I mean, that's the majority

of the tarsal tunnel scanning.

I'm looking for space-occupying masses.

I am looking for FHL, tenosynovitis, ganglion cysts,

anything that's going to compress on the nerve

as it traverses that narrow entrance to the tarsal tunnel.

And making sure that the nerves look uniform,

that I don't have any swollen fascicles or schwannomas.

Throw the color on if you suspect anything else

could be in the area.

But that is pretty much the parameters.

You can go long axis on this,

but there's not a lot of correlation

in seeing issues with the nerve

and long axis here at this level

because that that tunnel's so broad,

there's a lot of room for the nerve to move anyways.

But long axis can help you correlate

a long and short axis for diagnosis.

If you're guiding procedures in this area,

say to a posterior subtalar joint,

which will be covered in a future lecture,

it helps to have what's called the color compare tool on.

So we can throw our color on

and hit either the top bottom here.

And we could be doing our procedure

from the posterior aspect here, for example.

And we could be running a needle underneath the vessels

and underneath the,

underneath all the scary structures

into that posterior subtalar joint

while simultaneously having color on.

So we would see the procedure showing up at the bottom.

While we're still live, we can still see the artery,

we can still see the veins,

and not interrupt our procedure

with all that flash artifact from a needle.

So just one thing to consider when you're doing procedures.

As all the tools in your toolbox,

color compare is a really good one.

You can also go side by side.

Side by side cuts off the sides of the transducer

to center the image.

And I think it can look a little bit confusing,

like that's all one image.

So top bottom is my favorite.

So that does it for the tarsal tunnel.

We're not going to take any measurements here

because there's no standard.

There are some articles out there,

but there's no real,

real standard out there that everybody follows,

like the carpal tunnel.

It's just good to look at the nerves,

see what might be occluding 'em,

any space-occupying masses,

any nerve diameter changes,

all those things that we look for

in the other nerve entrapment pathologies.

But here, there's no standard for, you know,

how big is the medial calcaneal,

or sorry, the medial plantar,

how big should the lateral plantar

or how big should the calcaneal branch be?

There's no standard on that

like we have in the carpal tunnel.

So it's all relative.

Scanning, checking with the other side is good practice,

but for the most part, that's it for the tarsal tunnel.

I do thank you all for joining us here today.

That does conclude the webinar's recorded portion.

We'll move over to a Q&A at this point.

- [Chris] Yeah, absolutely.

Like Daniel said, we're taking questions now,

so you can go ahead and put those in the Q&A box,

either at the bottom or the side of your screen there.

And yeah, the next final part is on Tuesday, October 11th.

And that is using ultrasound to evaluate the lateral ankle.

And for information on that, to sign up for that,

you can visit our webinars page from the Sonosite website

at secure.sonosite.com/behindthescanwebinar.

- [Daniel] Thanks, Chris.

We'll give it just a few seconds

and see if those questions come rolling in.

Sometimes we get questions.

They're not recorded,

so just know that your question

will not be a part of the recording.

So don't feel shy, like you can't ask anything.

We're not going to repeat it on the recording.

But...

- [Chris] Yep, I don't see anything

coming through at the moment.

- [Daniel] All right.

- [Chris] Yep, so let me thank you, Daniel,

for taking the time to put together

this incredible presentation for this webinar.

Just a ton of excellent information here.

So, everybody, thank you so much for joining us.

And like I said, Tuesday, October 11th,

is using an ultrasound to evaluate the lateral ankle.

And hopefully we'll see you then.

Thank you so much for joining.

Ultrasound can extend the physical examination of the ankle while reducing the cost of care. Join this webinar to review normal sonoanatomy and commonly imaged structures of the medial ankle. Our expert presenter will scan live and demonstrate how to assess the tendons, muscles, complex deltoid ligaments, and tarsal tunnel of the medial ankle. A live question and answer session to clarify points and assist with overcoming learning plateaus from previous ultrasound education about the ankle is also included. Introductory and intermediate users of ultrasound will benefit from this webinar.

What You'll Learn

  • Confidently identify the boney landmarks to help navigate the structures in the medial ankle
  • Identify anatomy to avoid during needle procedures of the medial ankle
  • Review tips, tricks, and pitfalls of ultrasound imaging of the medial ankle
Daniel Shelton
Presenter: Daniel Shelton, RT(R)
Job title: Director, Musculoskeletal Market Development, FUJIFILM Sonosite

Daniel Shelton, RT(R) is the Director of Musculoskeletal Market Development for FUJIFILM Sonosite. Daniel spent 18 years as a dedicated musculoskeletal sonographer and 12 of those years have been here at Sonosite. He now leads musculoskeletal market development, where he works to spread the word about the benefits of point-of-care ultrasound.

Related

This educational webinar is intended for healthcare professionals and not for patients or consumers. The material is provided for general educational purposes, as a reference and a supplement to professional experience, education and training, and should not be considered the exclusive source for this type of information. This educational webinar is not intended to recommend any device for a particular indication or to provide indications for use for any device. At all times, it is the professional responsibility of the practitioner to exercise independent clinical judgment in each particular situation. Fujifilm assumes no responsibility or liability for any misuse of the information imparted in this webinar. This educational webinar does not supplement, replace, or supersede device labeling, including instructions for use, which accompanies any FUJIFILM Sonosite product.