Contact Sales
Duration:
Broadcast:
Topics: FP/GP, Orthopedics, Physical Med & Rehab, Sports Medicine, Sports Team, and Surgery
Related
Subscribe

Never miss a webinar!

https://www.youtube.com/watch?v=vw-R_pTqZKI
Transcript

- Well thanks everybody for joining us.

Hi everybody, my name's Chris Pennell

and I'll be moderating today's webinar.

Welcome to the rerun of the

behind the scan webinar titled Ultrasound Evaluation

of the Knee Part three, the Posterior Knee.

Now this is the third and the three part series on the knee

and you can watch the previous parts

of this webinar on sonos site.com/behind the scan webinar.

You can also scan that QR code

to go directly to there as well.

You can check out what's happening on our,

with our webinars, see what's upcoming

and sign up to them for reminders on when

they're happening as well.

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

We'll be conducting a q and a session at the

end of the presentation.

However, we're currently broadcasting this webinar on

multiple platforms

and in order for us to see your questions,

you must be on the main zoom stream.

If you're on the zoom stream,

you can type your questions into the q

and a box in the toolbar located at the bottom

or the side of your screen.

This webinar will be recorded

and archive for future reference on our webinars page.

Here with us today we have Daniel Shelton.

Daniel is the director of musculoskeletal market development

for Fujifilm Sono site.

Daniel has spent 19 years

as a dedicated musculoskeletal sonographer

and 14 of those years have been here at Sono site.

He now leads musculoskeletal market development

where he works to spread the word about the benefits

of point of care ultrasound.

Daniel, let's go ahead and get the presentation started.

- Thank you Chris for that introduction.

We'll go ahead and get started

- And reminder, this is the last

of the the three part series, so we can also do some recap

during the last part of the q and a from the live scanning.

We'll jump right into it about the anatomy

of a baker cyst in the posterior knee.

We typically start in a short axis

transverse to the body plane.

We're looking for this bony landmark here

of the medial epicondyle.

When you find the medial femoral epicondyle,

it's gonna have this nice hyper coic cortex

and it'll be capped in this koic articular ine cartilage.

It's not fluid. You can compress it with your transducer

and just be sure of that.

But first and foremost, look for these bony references.

We're gonna see the medial aspect of the knee,

the medial femoral con.

Next we wanna identify the semiosis semimembranosus

and the medial head of the gastro.

So you can use an isotropic to your advantage

and typically one

of these is gonna be brighter than the other

because they're kind of crisscrossing

as you can see in the diagram.

But the semimembranosus is not attaching just yet.

It's gonna end up, if we slid the probe distally,

we would see it attaching at the tibia, so the medial head

of the gastroc, this is the tendon.

And then here's the muscle, the muscle belly

of the medial head of the gastroc.

This little space right here is where

- We're looking for a VA cyst, the space

between them, where does this compare to the

- Neurovascular structure and are we close to that?

The same anatomy? So we can see the joint communication

of a baker system, how it gets trapped

and the overlying semi tendinosis can be a good landmark of

where we are in relation to the semiosis.

But moving over here you can see just

how deep the underlying neurovascular structures are.

They're pretty far away. You should use colored in your

advantage anytime you can.

Baker cyst is typically kind of a comma shape

and to, to locate that, we'll just take a slice

through the anatomy and we'll follow the

animation on the right side of the screen.

You can see these also in the Sono Site Learning Institute

if you wanted to slow those down.

But we have the medial head of the gas rock.

We have the semi menos coming to attach

to the posterior tibia

and we're gonna be looking for the baker cyst

to show up in this little space here.

The fluid is typically pretty compressible,

especially in the top end of the stock,

but this part you can see

that it really highlights the medial head of the gastroc

- In its muscle fibers.

Throw on the colored ler

and see what to avoid during procedures.

And we have highlighted the

anatomy here just for your reference.

Long axis should always be

double checked anytime you're suspecting

- Pathology.

And let's go ahead and see that animation.

Also at the Learning Institute, if you wanted

to use this reference your own material

and to colorize the anatomy here.

So we can see it's not two cysts,

but we're just looking at a slice through

where the cyst is curved

around the medial head of the gas rod.

We have perivascular fat around the neurovascular structures

and here deep, we can actually do this in the live study.

We see the PCL in long

axis attaching to the posterior tibial.

What if we move lateral and we see a

similar cystic structure?

Is it considered a baker cyst?

It would be just considered a ganglion cyst.

So the definition of that baker cyst needs to be sandwiched

between the medial head of the gastroc and the semiosis.

And then as another landmark in reference laterally,

we're gonna move over and scan the biceps fems,

see its relation to the la VAs laterals.

And then after we cover the skeletal structures

and the musculus region,

we'll get into the neurovascular structures.

But I want you to see the,

kinda like we covered in the last webinar, I,

I think it's very important to know

where the biceps femes ends

and the lateral collateral ligament also shares

that tapered insertion.

And then also more importantly,

to find another skeletal reference point fibular head,

we should see that biceps, femoris tendon

and long axis accompanied by this muscle belly.

- Alright, so if you'll just give me one second to set up

in the live demonstration area. We'll get

- Started.

Okay, so today we're gonna be scanning

with the sono site St.

This would release this year.

Transducer we're gonna use is pretty bread

and butter for most MSK,

but this is the 15 to four L 15 transducer,

so it's a large footprint, 50 millimeters across.

And we'll start in the transverse

orientation on the posterior knee.

So the default depth is it looks like 2.8 centimeters.

I've got the orientation marker medial, so the left side

of the screen you're gonna see will be medial as well.

We'll just see what we can see at the default settings

and place the transducer hopefully over a

skeletal reference point.

So right now I don't see a skeletal reference point

and that's where you wanna start troubleshooting.

And to troubleshoot this, lemme get the cord outta your way.

I like to wrap it around my arm anyways,

it makes it easier to scan.

So if you just get a blurry fuzzy, you know, left side

of the screen here, let's get an arrow up here.

I'm looking for the medial femoral condyle here, mainly

because I can kind of feel it with my finger.

I, I'm kind of palpating as I go.

This is the medial head of the gas rock over here

and it's tendon somewhere over here.

But I need to find that skeletal reference point.

So to troubleshoot that, what I have

to do is tilt the probe either distally,

which there is a skeletal reference point there.

I don't know if it's the femur or not,

or approximately this way.

So we have two skeletal reference points.

So how do we decide which is, which one

of them should have a big cap

of articular lene cartilage when we hit it at 90 degrees?

And that's what we have here. So this right here is the

articular lene cartilage.

I should be able to follow that valley down

and see one on the lateral side too.

So here's the lateral femoral condyle, not

to mention our neurovascular structures,

which we'll get to next.

But now I'm gonna go distal

and I wanna see the next skeletal reference

point, which should be tibia.

So I should fall into the joint and see nothing

and fall on top of the tibia, which doesn't have that

articular lene cartilage cap.

So we're on the tibial portion

and I can tell that there's a tendon here

because it's an isotropic.

And we're gonna use angle artifact to our advantage.

So right there, I'm just using the tilting of the transducer

to isolate the ember noses.

Okay, it's this whole broad stripe here.

The medial head of the gastro is this little section right

here and its tendon tendonous portion is just this thin

little sliver edge up here is semi tendinosis,

semi semit right up top.

So semi tendinosis miosis medial head of the gas rock here.

And I'm looking for a fluid collection in this little,

this little crevice that sits between the two.

So I'm gonna go proximal, proximal, proximal.

And there I can see

that medial femoral condyle in its cartilage.

I'm gonna give myself a little bit of depth either

by pushing the button or dragging the dot on the screen.

And there I can see that kind of valley in

between the two femoral condyle.

So that tells me what level of the femur I'm on

and what I should expect to see.

Let's get that arrow back up.

So I'm looking for fluid

to get trapped up into this space here.

We don't have a baker cyst today to look at,

but what I wanna make sure everybody walks away from is not

calling this a baker cyst,

this angular artifact in the early days

of everybody's learning curve,

I think anti isotropic artifact really

gets the best of people.

And I have seen, I have seen needles driven

into this guy right here in hopes that it was a baker cyst

and after a dry tap

and nothing coming out basically, you know, saying,

oh it must be a solid, you know, chronic

incompressible cyst.

You just, you know, other options, you know, and,

and basically in that early learning curve,

if you're not tilting every chance you get,

and let me just kind of illustrate the crisscross nature

that we kind of talked about in the slides right here.

So the gas rock is diving at this

point to the medial femoral condyle at its origin, right?

And then the semi menos here is diving to go

to its distal insertion on the posterior tibia

and they cross each other right here.

So they make this kind of scissor pattern,

especially when they go long axis.

It's very, very easy to see.

So I'm gonna take that slice right here

and we're gonna go long axis right through that plane

and you'll see the two crisscross.

So here we have a diving semimembranosus going

to the posterior tibia very nicely, a little air gap.

I'm gonna add a little gel. And if you ever find yourself

trying to get right back to where you started

and you're kind of new to this ultrasound stuff, basically

what I'm gonna do is let up pressure

and I can see the indentation on the skin

and I can see the little rectangle where the gel used to be.

And I can just land a beat of gel right in

that, right in that gap.

There we go. So now we have a little gel standoff which

follows the curvature of the popliteal faucet here.

But let's take a look at this. We've got semiosis

and then if I, if I pull the entire transducer laterally,

we're gonna see the medial head of the gastroc

diving this way.

So just to give you that kind of illustrated look,

I'm gonna obliquely crisscross the two.

So now we have this kind of X pattern right here

and this is the area where the baker cyst out pouches in

between those two tendons like this.

So the cyst pops out between the crisscrossing

of those two tendons and gets trapped

and it can only be dealt with by, you know,

I mean if you aspirate 'em, they come back.

But if they're painful, you know, it might be worth

alleviating the pain from my, from what I understand, a lot

of pressure can build up in those.

Incidentally, it's kind of nice we can see the posterior

medial meniscus in its periphery.

You cannot see the deep inner edge on everybody,

but on some people you get pretty lucky.

You can see meniscal cysts back here pretty easily.

Not to get too off topic,

but we're gonna stick with the baker cyst kind

of dos and don'ts right there.

So how close are we to the vessels?

So I'm just gonna rotate the probe

and keep that medial side of the transducer screen left.

Here we go. And I'm gonna go back up into the level

of the condyles

and at the level of the condyles you'll notice

that the great vessels are kind

of hanging out on the lateral side.

So medial pressure left side of the screen, if you,

if you are doing one of these procedures, it, it's kind

of a safer approach to either go this way

or even longitudinally from medial to lateral, kind

of semi oblique whatever approach gives you the thinnest

throw to your target.

But yeah, here's our neurovascular structure.

So we have the popal artery, vein

and nerve stacked on top of each other here.

And it's a, it's a highly vascular area.

A lot of, a lot of no-go zones back here.

And if you ever want to know what's a vessel

and what's not, just don't forget you have color.

So hit the C button on your machine, you can expand

your doppler region of interest, your ROI

and see all the vascular

structures that you don't want to hit.

So if you do happen to be driving a needle in this area,

you wanna have your your color screen active right in here.

And then I would advise that you either do left, right

or top bottom to do a color compare.

So I'm gonna hit top bottom

and we can simultaneously be running our color in our needle

on the bottom and making sure,

because doppler catches anything that's moving.

So if your needle is entering the field

and you're trying to drive a needle near vessels,

this can be a very helpful mode to make sure

that you're not setting off all

that doppler motion while you're driving a

needle in the soft tissue.

So you'd be watching the bottom screen

and watch your needle drive near the vessels

or if you're doing a nerve block, that's also good practice.

If you feel confident

that you can keep your structures in the middle

of the screen, you can activate the left right button on

your ST or PX or lx.

This is all three machines right now

and it's more full screen,

but it does cut off the edges of the transducer

unless you drop your depth.

So I'm gonna bring my depth way down if you wanna capture

the full width of the transducer when you're doing that,

you will lose a little resolution, just a little

machine scanning tip if you're new to the SonoSite systems

or you have not seen the newer sono cyte systems,

I just want you to know the controls of your machine

to get rid of your color.

I'm just gonna hit 2D

and that'll get us out of

anything that we didn't wanna have.

So here we can see that sciatic nerve.

Actually we're gonna get into that on the next set

before we get too carried away scanning the cool stuff,

let's go ahead and go over those slides.

But short axis we've got semimembranosus medial head

of gastroc anemia junction,

that little bursa pocket there long axis.

You can see the two crisscrossing each other.

You can see beautiful deep posterior joint anatomy.

And then just for fun, it wasn't in the slides really,

but here we can see the PCL.

So just kind of as a, a party trick, I'm not sure

that it's super reliable ultrasound to do PCL scanning.

I think you would want to have them standing

and do some dynamic stress maneuvers to,

to evaluate the PCL back here.

But you can see it so you can tell if they've got a,

a cyst arising from the posterior knee.

Is it coming from the capsule around those PCL

or ACL on the anterior knee that we did?

And the origin of the PCL is not something to kind

of hang your hat on very much.

It, it's, it's kind of difficult to see.

But if you were to take the probe back to short axis,

let's go back to the tibial portion.

So we're on the tibia, we're, we're at the distal

and thesis of the PCL.

So here's the PCL

and I'm just gonna jump across the joint line

and we're just following, and you'll see this dark oval

start to hug the medial femoral condyle.

And that's about as great a view

as most people typically can get right there.

That dark oval is what you're going for.

So that's not a cyst either.

Just as a pitfall, ligaments are more dense

so they're more subject to anti tropic artifact

or angle artifact if you're new to this.

And you can make this look like a

cyst just by having the wrong angle.

So always check your work, check your angles.

Okay, so that's kind of a little bonus PCL for joining

the webinar with us today.

And don't forget to have your questions queued up

in the chat for Chris.

He'll be moderating the the q and a after we're done.

But now I'm gonna, I'm gonna throw back over to the slides

and we're gonna go over the neurovascular structures

in the posterior knee.

Alright, let's move on to the neurovascular structures.

So the posterior knee, this is a lot of fun really

because we did briefly touch on some

of the neurovascular structures in our,

in our last meeting together.

But we're gonna be covering basically the,

the sciatic bifurcation as it as it branches off

to the common peroneal and then down into the tibial

or the popliteal nerve before it becomes tibial.

And then we will watch these divisions.

Many, many divisions can come off in the form

of these little sile branches,

which can be appreciated with ultrasound.

But mainly I want to go over the scanning tips

and tricks to finding this common perennial nerve

and making sure that you are able to identify

that bifurcation and what

to do when a normal nerve doesn't look normal anymore.

So what is a normal nerve?

Well these nerves, as we've studied in other parts

of the body, they typically have this kind

of compact honeycomb appearance.

They travel between muscle planes,

which is a good way to identify them.

And the nerves are typically accompanying the,

the vascular structures of a, of an artery.

So we always wanna put on color as a roadmap if you can.

If you ever get lost tracing nerves, most of them

are accompanied with a an artery running in tandem.

But here we have the distal sciatic nerve

and as it's branched off, we,

we don't see the branch off just yet

of the common peroneal nerve,

but this is the, the look that you would want to get.

And then we'll go proximal distal, proximal distal

and short axis just to pan through the nerve.

But when we turn the probe and long axis,

we should see these very, very parallel fibers.

Tendon does not behave like this.

Tendons kind of have this basket wo pattern

where you don't see individual fales

that follow their length entirely.

So being able to follow each individual fale

of a nerve is a huge advantage

of identifying what's a nerve and what's not a nerve.

And then your epineurium, which is nice

and bright typically is less angle

dependent, it's mostly fat.

It shines very, very hyper coic even when it's diving

and that's what makes a nerve easier

to identify than some of these tendons.

Let's look at a soft tissue mass on the posterior knee

that was confused for a baker's cyst.

This study was done a long time ago on a previous machine,

but it's still super relevant to what we're looking at.

So basically we have our normal structures on the left

that we just went over and then screen right, we start

to see a difference in the pattern.

We could palpate a mass not quite the size

of a golf ball on the posterior knee.

It was sent to our department that I used to work at

as a potential aspiration of a baker cyst.

And they just wanted to know was this collection in the back

of the knee, was it solid or cystic

because it was causing a lot of pain

and they knew the patient needed to have some sort

of relief.

So to provide that relief, they wanted to aspirated

but first they want, they sent it to us to find out

can it even be aspirated?

Is it solid or cystic?

Which ultrasound does a tremendous job at at determining.

So here we have the, the medial head of the gastroc

and the lateral head of the gastroc and then this huge mass.

And then if we look closely you can see other branches

of this mass just below it.

But when we go long axis it really paints the picture,

especially compared to the normal nerve.

So the normal nerve we see that train track kind

of appearance and then following the epi, watch the borders

of the epineurium swell.

So here we have this first kind of egg shape pattern.

So when we were scanning this in short axis, the first thing

that we, that we saw in this slice was the beginning

of what looked like a cyst.

Could be a ganglion cyst, could be whatever,

but the fact that it was in the path of the nerve,

it was suspicious for a a sonoma.

And and the more we panned this land took this slice here

you end up with this giant hypo coic cystic structure.

And if you only take this slice out of context,

then you may just call this a baker cyst

and send them on their way to the aspirated.

But that's why we have to image things in two planes

and MSK, everything is angle dependent.

Everything has to be imaged in two planes

where the study doesn't count.

So this is one of those times

to really double check your work

and then kind of did poor man extended field of view kind

of thing where you can stitch your images together.

So if we have a 50 millimeter transducer as we do

with the HFL 50 on our previous machines

and we do have on the L 15 on the demonstration this

evening, you can just split the screen

and essentially bring your depth down which is

also good for perspective.

Here's the posterior tibia and the posterior joint line.

Basically what we're seeing here is a stitch together image

that would be about 10 centimeters across.

So if it gives you any idea here what we're looking at,

I would say that the entire schwannoma structure is not

quite 10 centimeters but it's pretty long.

It's probably eight centimeters in length, I don't remember

what the measurement was on this date,

but split your screen, drop your depth to get maximum field

of view, slide your transducer just a little bit distal

until you match up your pattern

and you actually get an extremely

accurate, wider field of view.

It's very nice. So dual screen imaging is not just

for comparison, it can actually lengthen

what you're looking at nicely.

Next structure. Let's look at the common perineal nerve.

Went over a little bit of the shortcut on how

to identify this in the last webinar,

but let's refresh your memory tonight.

We're gonna identify the biceps femoris, we're gonna

travel all the way to the fibular head.

I want you to palpate the fibular head with both

of your fingers and pinch it between your fingers.

Set the transducer right between your fingers

and it should land you on the fibular head

and one strided structure.

So it's either the biceps femoris

that you're gonna see or the LCL.

So you just need a a windshield wiper, the proximal side

of your probe and decide if you're seeing epicondyle.

So that would be LCL more anteriorly.

Or if you're seeing more of a full length tendon

with a little bit of muscle belly here,

that would be your biceps femoris.

And we'll do that in a live demo just as a reminder.

But when you slide your transducer just posterior

to the fibular head in that same plane

as the biceps femoris, you get this really beautiful

common peroneal nerve

and it's just a great way to check your work.

You can always start in short axis from the sciatic

bifurcation, that's fine.

You sometimes lose it

as you'll see in the live scan how easy it is to lose.

But as a quick shortcut you can go to the fibular head,

find your biceps femoris and long axis

and then just drop your whole transducer posteriorly about a

centimeter or two and you should come across this

really nice nerve.

Alright, so let me get us set up for

the last live demonstration.

And just as a reminder,

after the last live demonstration we'll be open

for question answer.

Those are also live

and you can ask Chris your questions,

you can type 'em in the chat is the,

is the way to communicate.

And if you're joining us over other streaming platforms,

it's very important that you join the zoom link

through the webinar to type in the chat

platforms like YouTube are 10 seconds or 15 seconds delayed

and we don't always have a chance to check the,

the chat feed on on those other platforms.

So it's very important to ask your through the zoom portal,

have those queued up and ready for the end of the demo here.

And then we will, we'll have our recap.

- Alright, - So back to the live demo. Here we go.

I think these structures are a lot more fun to scan.

I when it comes to the poster posterior knee,

the baker cyst stuff is, is really neat and relevant,

but I just think imaging nerves is super fun.

So here we go back to cortical landmark.

So this is medial, we have the medial femoral condyle,

lateral lateral femoral condyle capped

with articular hylan cartilage

and then vaguely in the middle all

that dirty shadowing there is just the groove

that our neurovascular structures are sitting in, right?

So let's, let's do the traditional way

to find the coop peroneal nerve

because I think that's the one most people have

a hard time finding.

So the traditional way to do it would be

to go find your sciatic right here.

And the problem is with a lot of sciatic scanning,

I see people troubleshooting,

see this muscle here we've got this big old gracilis,

maybe gracilis, semi tendinosis,

okay, so we have this big semi tendinosis up here,

but as we go more proximally, look at its edge, the edge

of the muscle and its fascia casts this,

this dirty shadow over your neurovascular structure.

So this can be part

of the learning curve of finding a nerve.

So if you're at the wrong angle, like here,

if I rock my probe outta the way,

see the shadow is now laying sideways

and we're transmitting sound through the shadow,

here's our nerves right here.

But if you're rocking the transducer this way, watch

that shadow cast right over the nerves

and then all of a sudden your image is like this,

it looks grainy and kind of ugly

and it's hard to identify

where this attic nerve begins and ends.

Whereas it's margins, is it splitting or not?

So just keep, keep an eye on if you're perfectly axial,

you may be casting edge artifacts from the overlying

muscle bellies here.

Semi tendinosis up here is

what we saw biceps femoris up here

and then the, the septum between the two is casting

that big shadow into your neurovascular structures.

But we're watching this guy here.

So anytime you wanna scan a nerve

and make it look really nice and pretty

and you see an overlying muscle like the biceps femoris in

this case what I'm gonna do is take this nerve

and I want it to be in the shadow of the muscle.

'cause the muscle is relatively water filled and fluid dense

and it's, it's gonna enhance the underlying structure.

So if I can take this slice,

I can make this nerve look really, really pretty.

So let's try that. I'm gonna go lateral

now the biceps femoris is in the middle of the screen

and now what I'm gonna do is rock the transducer this way.

And what that does is it,

it casts what's called posterior acoustic enhancement

or it's basically the muscle is shining

sound much better than through the dirty shadow

between the two muscles that's cast by the edges

of their tendons or their fascial planes.

Everybody see the difference there?

So you can rock your transducer

and try to throw the nerve under muscle bellies anytime

you're scanning nerves, that's

one way to troubleshoot nerves.

Here we are at the bifurcation.

So let's watch this guy right here about, what is

that one o'clock, two o'clock?

I'm gonna spin my arrow

because I don't like its location right now there.

Let's just get it outta the way

and let's look at this guy right here.

It's gonna cast when I go proximally in distally,

you're gonna see it make itself known.

And what I'm gonna do, so that you can see my hand here

as I traverse the nerve distally, I'm gonna go back

to proximally distally, proximally distally.

And then I'm gonna keep moving the probe distally again

about an inch or two.

Then I'm gonna go proximal distal, proximal distal.

I'm gonna keep panning across the structure here.

Did you see the nerve here?

Which was nice and echogenic all

of a sudden it takes a sharp upward move there

and when it takes a sharp upward move it turns dark.

And that's because of the angle artifact associated with it.

So what I have to do is match the angle that it's trying

to climb.

Here we go. So now I'm 90 degrees

to the nerve but not the skin.

Okay? So we're gonna follow that and,

and here you see it tucking up against the biceps femoris.

So this is kind of the traditional way to try to follow

the common peroneal nerve right up here.

And now we're at the level of the medial

or the lateral femoral condyle, which is good.

And then to focus on this anatomy a little bit better,

what I'm gonna do is decrease my depth.

Let's go up shallow and you're gonna see all the margins

really pop, all the fales really pop

because the machines focusing for you in the near field.

So here what we see is the,

the nerve is now flattening out a little bit.

I see the tendon, the an isotropic tendon

of the biceps femme and

because it's such an easy landmark to scan anyways, we might

as well just go find that like we ended our last webinar,

we scanned a little bit of perennial nerve through the q

and a and let's go over what that approach was.

So I'm gonna roll our patient's leg out a little bit.

I'm gonna feel the fibula.

So all right, there's the fibular head.

I'm gonna pinch it between my fingers.

So when I pinch that head between the fingers,

I'm just gonna rest the transducer right

between my two fingers

and I should see a bony landmark that I'm pinching

that screen left, I'm gonna flip it right?

So left side of the screen's proximal right side is

where my fingers are pinching, right?

So if I'm anterior I get an LCL

across the screen jumping over the popliteal groove

to the lateral epicondyle.

Everybody appreciate that.

So what I can do is just drag my arrow across here,

here's LCL popliteal groove

of the femur joint line tibia

and then fibula up here.

Okay, so if you have that shot, you're not posterior enough.

So what I'm gonna do now, keeping

that same pinch on the fibula, I'm gonna drag

or windshield wiper the probe to the midline

and it's gonna elongate a very long

tendon superficially.

So now we have same fibula.

So we have fibula here

and then here is the tendon of the biceps femoris.

And if I keep climbing proximally, I'll see the muscle belly

that we saw in the slides.

Muscle belly of the biceps femoris here.

So this is all muscle belly biceps fem it.

So if you catch that in long axis, the biceps fems,

a really nice and easy to adjust shortcut is, is basically

to get that biceps femoris in long axis

because they run parallel to each other.

And I'm gonna slide the entire transducer posteriorly

in the same angle and we catch the common peroneal nerve

and it's long axis, which is nice.

And then you can just trace it down to the fibula.

If you see the fibula you can go a little bit more posterior

midline again

and just rotate your transducer until you elongate it.

And sometimes that long axis nerve helps us catch

the defects or the entrapments

or neuromas in more of a context there.

There's that dive. Remember when the nerve was diving on us

go down in depth label up here, that's where I had

to match the angle of the common peral nerve right there.

That's where I had to angle my

transducer to match that curve.

So if you're having trouble with this particular nerve,

just remember it dives

and when it dives you have to match its angle.

Okay? So let's keep following

that perineal nerve up to the fibula.

Again, if you see fibula in the shot,

you're not posterior enough.

So slide a little bit more posterior. There you go.

And then after the fibula, you see the fibular neck start

to come in down here and that's where you have

to rotate the transducer

and you'll catch where the nerve decides to split.

So you can either do this in long axis or short axis,

but if you're gonna go back to short axis,

find your common landmark of the fibular head.

Here we are fibular head and I'm gonna

rotate the transducer.

There we go, right there.

So biceps femoris, peral nerve

and let's follow that perineal nerve

approximately and distally.

So here it is, distal, distal, distal,

right there you can see that tight, tight compartment

that the nerve sits in right here.

Let's rotate that guy there.

Not much room and that's a common point of entrapment.

And here we see it split to its its posterior,

anterior divisions here for the deep and superficial

and you can just keep tracing it down.

Did you see the angle I had to do on the video

to match the nerve as it traversed?

Really you want to keep it pinned between a bony backboard.

So what I mean by that is I have a bone here, the nerve here

and the transducer all in line.

What you don't want to do is have this oblique angle

where you're taking a long axis shot of the nerve

with no skeletal reference point

if you can, if you can afford it.

So in long axis this is what the nerve would look like

'cause we have that nice skeletal reference point

behind it, which is fibula.

So catching the right angle it can really put the nerve into

into context where it is on the body.

So we really made our way down the screen

and almost off the camera there, let's go back

to the main tibial nerve and the sciatic

and let's give it some depth.

Let's just drag the dot. There we go. Okay, so here we go.

We've got tibial component

and just following it till we see tibia more superficially,

there's the level of the lateral femoral condyle still

following this, this nerve here.

And here it is resting on the top of the posterior tibia

and that's the level that we, we found that schwannoma right

as it was diving off.

And, and I'm gonna go long axis on this too. There we go.

And we can see those same vascular landmarks,

you can see the branches of the nerve as they try

to take off with the arteries.

Always check things in two planes.

Long short axis, everything you do.

But that's pretty much it.

I think we should take the questions now.

Chris, if you don't mind, let's, let's start on the,

on the chat just to kind of address any, any,

any follow up questions to the last webinars.

We're very happy that you guys have joined us,

what we did in the last session, just to test the chat

and help us out, just, just type in where you're,

where you're logging in from, where,

where are you watching the webinar from

and it's, it's one way to verify to us

that our chat feature's working or the q

and a portal's actually working.

- Yeah, thanks Daniel.

So yeah, like Daniel said, we can go ahead

and take some questions now

we can only take those on the Zoom broadcast and the q

and a box should be either at the bottom

or the side of your screen.

So if you have any questions for Daniel, go ahead

and type those in.

Now it looks like we got one coming in.

Lisa Satler says hi, watching from New York,

we've got one from list wall Ontario, Canada as well.

Yeah. Daniel, do you have any, you're using the st

is there any functions kind of, of the ST

or kind of the form factor of the ST that kind of helps

with your MSK work?

- You know, it's such a procedurally based machine,

but the image quality is, is standard with our,

our current family of zone effect products.

So, you know, if if you're, if you're,

you know, even looking for a machine, you, you should just,

the form factor these days really

because the image quality on a machine that is set up

for procedures like this is very important.

And having this big upright touch panel and

and wiping it down really fast between patients I think is,

is crucial for a lot of facilities.

So it's just the cleanliness of the machine.

I like, I think you can see the transducer

holder yeah, on the back.

They have these really cool arms.

So a lot of people are kind

of solo artists when they're doing their, their procedures

and you have to figure out how

to cover a transducer yourself.

So I like that we put these little arms on the back

of the ST and it allows you to stand

behind the machine away from the procedure site.

There's a tray on the back,

which is not super visible on the video,

but you can set your procedure supplies up back there

and it acts like a tray table in two arms holding

the transducer for you.

So when you get your probe cover out,

put the non-sterile gel on the top of the probe,

then you can use your probe cover like a little puppet show

and just grab that yourself without

having to have an assistant there.

I think just those little features of, you know, how the,

how the system is set up obviously

and just kind of keeping in in mind the, the users that are

more often than not in the procedure room

by themselves doing a lot of these injections

and just making it easier and the,

and the very little button pressing,

I don't know if you guys notice that or not,

but you know, if you're busy doing procedures,

you really don't have a lot of time to, to, to,

to be changing your frequency constantly or your focus

or edge enhancements or persistence

or other, other things that go into traditional systems.

So user friendliness, cleanliness,

and it, it's a very durable, rugged machine.

I think, I don't know,

I think I almost need like a bathroom scale in here so

that you guys can get a, a sense of just

how sturdy this thing is

and that it's not, it's not gonna fall over it,

it's a very solid machine.

So a lot of, a lot of clinical considerations went into this

machine and,

and it sure does not lack the image quality,

which I think everybody can see online, which is nice.

- Nice. All right, we don't have any questions

coming in quite yet.

Okay. Is there anything else that you wanted

to kind show us on the posterior knee here?

- You know, from a nerdiness standpoint, a lot of people,

you know, we don't scan a lot of the posterior ligaments.

- I don't have an answer for that. Yeah, is there something,

- You know, these, these things are always

listening to us, aren't they?

Okay, so I went over a little bit of the PCL, which is fine,

it's a ligament and there's other

ligaments in the posterior knee.

I think we had a comment on one of our YouTube comments

to take a look at a posterior oblique ligament, which

honestly I don't have a lot of experience scanning,

but it's not that hard to find

and I would imagine this would need

to be done weight bearing.

So it's kind of helpful in not having hyperextension

of the knee, but basically it's a a, a very broad ligament

that jumps over the rest of the articular capsule.

It does climb under the semi menos.

So if you can find semi menos,

I thought this was really cool, easy way to scan it,

find semiosis, remember that shadow that dies to the tibia.

So here we go, here's the tibia right there.

There's a second little layer underneath it

and that's what this, this posterior oblique ligament is.

And we're gonna take this, this part right here on the tibia

and then I'm gonna, I'm gonna use my lateral part

of the transducer over here

and I'm just gonna windshield wiper it over

to the lateral condyle of the femur.

And you catch this really, really pretty ligament bridging

this gap above the PCL.

So here we go. So this ligament right here is

that posterior oblique ligament

and it was just a fun challenge to take a look at.

I think it's fun to show people just the

non-traditional ultrasound scan.

And then a good landmark is this hypo coic shadow

that we went over earlier and that's your PCL.

So while you're in the neighborhood of the PCL

and you look just superficial to the PCL,

you catch this really, really nice pretty ligament

and it's long axis bridging the gap between the tibia

on the medial side just under semiosis.

And then he swing the lateral side

of the transducer over the lateral condyle

where this ligament eventually inserts

not only onto the articular capsule on the lateral condyle,

but I think most of it even wraps up

and around it to its cortical insertion with the capsule.

So it was a fun challenge, I thought it was neat to look at.

But other than that, I mean that's, that's not a common scan

but it is fun to just challenge yourself with some, with,

with anatomy in general.

You look at the structures

and you want to just keep in mind the angle artifact of Ms K

and to always try to throw your anatomy up against the bony

skeletal reference point.

It's very important. But yeah, I mean in general if,

if nobody has any questions, it's a pretty short subject.

Kinda like when we did the superior shoulder, you know,

you've got the AC joint and super scapular notch and,

and just a few other things that are considered, you know,

normal scanning windows

but the rest of it are kind of obscure

and you can, you can get lost in the weeds with anatomy

for sure and how much of it's clinically relevant

or not is also up for debate.

But we're glad you joined us today.

You'll see a QR code on the screen to sign up

for the future webinars.

The topics that are coming up, we'll, we'll continue

to do these other topics like we're doing

that we have done in the past and either replaying them

or redoing them from, you know, how, how the recording went.

Some of them recorded in a little lower resolution

'cause we were shooting them strictly on Zoom in the

earlier days of the pandemic.

So we're kind of redoing a few of these.

And then, and there's a few brand new webinars I think in,

we're shooting for midsummer to do the hand series

so don't forget to join us for the hand.

It's gonna be a three or four part series

'cause there's a lot going on in the hand.

And we'll also include a guest speaker, Dr.

Dan Malone is going to give us a really nice update on

rheumatology scanning

and clinical pearls of arthritis

that can happen in the hand and wrist.

So that's just a little update on our end we're,

we're staying busy with Ms.

K and we wanna keep you guys included involved

and interactive as much as possible.

But thank you for joining us today.

- Yeah, thanks everybody for joining us.

As Daniel said, you can see the QR code there on the screen

that'll take you right to sono site.com/behind the scan

webinar where you can see what webinars are coming up

and you can go ahead

and sign up for those to make sure you get email

notifications for when those are happening.

So thanks Daniel for taking your time

to put together this amazing presentation.

We appreciate you sharing your expertise as always,

and thank you everybody else for joining us today.

Watch this webinar to review normal sonoanatomy and commonly imaged structures of the posterior knee. Our expert presenter will describe and demonstrate via live-scan Bakers cyst location, neurovascular structures, and ligaments.

What You'll Learn

  • Review the anatomy involving a Bakers cyst and how to identify a false positive for a Bakers cyst
  • Confidently identify the boney landmarks to help navigate structures in the posterior knee
  • Identify what to avoid puncturing during an injection or aspiration of the posterior knee
  • Review the benefits and pitfalls of ultrasound imaging of the posterior knee
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.