Pitfalls: Musculoskeletal, Part 2

Focus on the Knee and Meniscus

What I'm gonna do is focus on just the knee.
There are a lot of things that we could have covered,
and made a whole day just on MSK pitfalls,
but I wanna just emphasize the knee
and in particular the meniscus
and how we can be better at identifying
meniscal abnormalities.

As you'll recall,
the meniscus is a fibro cartilaginous disc
that is she c shaped.
And when we slice through with a sagittal section,
you can see the anterior posterior horns make
up these nice triangles.
So for the moment we're gonna talk about the appearance
of the anterior and posterior horns.

Here's a fat suppressed pro proton density weighted,
image showing the low signal triangular anterior posterior
horn of the lateral meniscus.

Anterior Horn Pitfalls

Now first, let's talk about the anterior horn.
There are some pitfalls that we can encounter
that mimic tears of the anterior horn.
They include the transverse ligament
as it crosses the anterior portion of the joint,
the speckled anterior horn from the insertion
of the anterior cruciate ligament,
and the oblique meniscal meniscal ligament,
which we don't see that often,
but you definitely need to be aware of its presence
because it's certainly can mimic a tear.

So the transverse ligament first has this appearance
of a pseudo tear as it intersects with
and inserts on the anterior horn of both the medial
and lateral meniscus.
It becomes easy to recognize, particularly as you continue
to look at the sagittal images across the joint
to the other meniscus.
It traverses hoffa's fat pads.
So the presence of the fat surrounding the low signal
ligament makes it fairly conspicuous.
We don't see the transverse ligament in all knees,
but when we do see it, you need to be aware
that it's a normal structure
and that it's interface with the meniscus
represents a pseudo tear and not true pathology.
The function of the transverse ligament is still unknown as
to its true utility,
but obviously must be some sort
of a stabilizer for the meniscus.
And again, look at sequential imaging
to recognize this structure.

So here we see the medial meniscus and the lateral meniscus,
and we'll follow the transverse ligament across the joint.
And here you can see it on the third image in front
of the anterior cruciate ligament in the anterior
portion of the joint space.
And that interface with both the anterior horn
of the medial meniscus and lateral meniscus present a pseudo
tear appearance.

Now the speckled appearance
that we see from the anterior horn was described back in
1997 initially,
and the bundles
of the anterior cruciate ligament come down
and insert onto the anterior horn of the lateral meniscus.
So slice is immediately adjacent to that insertion
with partial volume averaging,
mimics then the speckled appearance that we can see.
So if you encounter what looks like a macerated appearance
of the anterior horn of the meniscus, look at the one
or two slices adjacent to where you're looking
to see if it represents the insertion
of the anterior cruciate ligament.
It's found in about 60% of all knees,
and again, recognize the presence
of the anterior cruciate ligament.

So here's such an example.
See the speckled appearance within the anterior horn of
that lateral meniscus.
And two subsequent slices over.
You can see the ACL
and appreciate that bundle appearance of the,
the fibers of the anterior cruciate ligament
as they individually would insert onto the anterior horn
of the lateral meniscus, creating that appearance.
What I've most often seen this misdiagnosed
as is a macerated anterior horn of the lateral meniscus.
Another example here showing more graphically the stippled
appearance of the anterior horn.
And then the adjacent slice, the appearance
of the anterior cruciate ligament.
And you can see grossly how the ACL inserts onto
that anterior horn.

Now, the oblique meniscal meniscal ligament,
it came into our literature back in 1999,
and it's an inter meniscal ligament that courses obliquely
through the notch.
It arises at the anterior horn of one of the menisci
and goes to the posterior horn of the opposite meniscus.
So obviously then crossing the intracon
or notch seen with the anterior
and posterior cruciate ligaments.
It's said to occur between one in 4% of all knees,
and it can mimic, particularly when you get
to the region of the notch.
The low signal of
that obliquely oriented ligament can mimic the flipped portion of the bucket handle
of a bucket handle tear of the meniscus.
So we need to be aware of its presence
so you can track it obliquely through the joint space.

So let's take a look at this structure.
It's a tiny little low signal,
and you'll see on the subsequent coronal images
how it's tracking obliquely through the joint space,
through the intercondylar notch arising from the anterior
horn of one
and inserting on the posterior horn of the other meniscus so
that when it crosses within the notch,
imagine a sagittal slice mimicking the handle
of a bucket handle tear.
And there you see, initially, if I were
to just show you this image
and you saw this, I think everybody in here would think
that we were looking at a bucket handle tear.
So just be aware of that appearance.
We don't now have to have a knee-jerk response
that we're looking at the handle of the bucket,
but instead we also want to track it forward and back
and obliquely to make sure that we're not looking at an oblique meniscal meniscal ligament.

So those are the normal variants
and pitfalls of the anterior horn.
We now also encounter pitfalls involving the posterior horn
of the lateral meniscus,
and they can mimic radial tears and peripheral tears.
And as we know, radial tears
and peripheral tears are very important for us to recognize
because peripheral tears, particularly if they occur in
that vascular interface,
can be very problematic if not diagnosed
and treated acutely.

Posterior Horn Pitfalls

The meniscus femoral insertion can lead to the appearance
of a pseudo tear also within the posterior horn
of the lateral meniscus, as can the pops tendon.
So the meniscal femoral li ligament can mimic a peripheral
tear as it attaches to that posterior horn.
One way to recognize this is to continue
to follow the structure all the way back
to the posterior medial femoral condyle.
It's present in about 75% of all joints.
And again, going through the sagittal imaging,
you'll be able to recognize if you're dealing
with a true tear or the appearance
of the meniscus femoral ligament,
if you identify the structure anterior
to the posterior cruciate ligament,
it's the ligament of Humphrey.
And if you identify it posterior
to the posterior cruciate ligament,
it's the meniscul femoral ligament of berg.

So let's look at this meniscul femoral ligament
as we track it from the posterior horn
to its attachment.
And you'll see that there is a high signal interface
between the meniscal femoral ligament
and the posterior horn of the lateral meniscus.
And the way to recognize
that this image is not a peripheral tear is to continue
to look at contiguous imaging
until you see the meniscal femoral ligament heading toward
the posterior medial femoral condyle.
Another example, we can see the interface
between the posterior horn of the lateral meniscus
and the meniscus femoral ligament.
And here we see that the meniscus femoral ligament is
anterior to the posterior cruciate ligament.
Making this a meniscus femoral ligament of Humphrey.

The pops tendon similarly can cause the
appearance of a pseudo tear.
It originates from the lateral femoral condyle courses,
obliquely and inferiorly,
and it goes between the posterior horn
of the lateral meniscus and the joint capsule.
And as it slides between the posterior horn
of the lateral meniscus and capsule, it mimics
that appearance of the pseudo tear at its interface.
Once again, looking at subsequent images, you can recognize
that this is the tendon of the pops and not a true tear.

So here on the sagittal images, we have the pops tendon
and the posterior horn of the lateral meniscus,
and it's this increased signal intensity
that represents the pseudo tear.
But as we look at consecutive sagittal images, we recognize
that this is the pops tendon heading inferior.
These are inversion recovery images demonstrating the same te
appearance of the pseudo tear
between the posterior horn lateral meniscus
and the pops tendon.

So in addition to the pitfalls of the normal anatomy
of the posterior horn, we do need to be able
to recognize the presence of peripheral tears,
particularly in the setting
of an anterior cruciate ligament.
We know that we under diagnose peripheral tears
of the posterior horn of the lateral meniscus in the setting
of ACL tears, so we have
to be a bit more sensitive about that.
In addition, we can recognize radial tears
and need to be able to diagnose those.
And importantly in something
that's been in our literature more
recently are the root tears.

So in this patient who has an anterior cruciate ligament
tear demonstrated here, we can see
that there is a posterior horn,
lateral meniscus, peripheral tear.
The way that we recognize that this is not then a,
a ligament of berg or Humphrey is on each image.
This will stay in contact with the posterior horn
of the lateral meniscus as opposed to migrating
to the region of the PCL
and inserting on the posterior medial femoral condyle.
So this stays at the posterior aspect
of the lateral meniscus, a peripheral tear.

So if you have an anterior cruciate ligament tear recognized
by seeing the disruption in the notch, large joint fusion,
also very supportive of that being an acute injury,
pay careful attention to the peripheral aspect
of the meniscus in general.
And in particular, the posterior horn
of the lateral meniscus.
If you see increased signal there,
lower your sensitivity of being able to recognize that
as a peripheral tear, as long as you can't see it migrating
toward the direction of the PCL.

Another example of a peripheral tear, the posterior horn,
this is a patient who had an ACL repair,
and you can see that we have a little bit of artifact
of imaging, but then the vertically oriented increased
signal at the peripheral aspect,
representing peripheral tear at the time of the ACL injury.
Another example, we have the contusion pattern suggesting a
more recent anterior cruciate ligament tear,
mid lateral femoral condyle,
posterior lateral tubial plateau
and vertical increased signal in the posterior horn
of the lateral meniscus.
So you see this, you turn your attention to the periphery
of the meniscus, you turn your attention
to the posterior horn of the lateral meniscus.
You recognize this.
Now your sensitivity for diagnosing an a,
a peripheral tear with an ACL goes way up.
And then you just wanna make sure that
that doesn't migrate away from the posterior horn
representing Berg or Humphrey.

Now let's talk about radial tears.
Again, these can be symptomatic
and usually are debrided to relieve the symptoms.
There are a few different appearances of radial tears,
and it depends on what orientation you're looking at.

So on the coronal images, we've described that
as a cleft appearance.
So you can see the radial tears at the free edge
of the meniscus.
And here we have this cleft appearance.
So imagine taking a coronal image through that.
You're obviously left
with a gap in the appearance of the meniscus.
On the sagittal images
because of the missing meniscal tissue, you would see
that there is a truncated triangle.
So the residual portion of the meniscus
is low in signal, but that portion of the meniscus
that's missing represents the truncated triangle.
And then finally, on the sagittal images
where there is no longer the appearance of the meniscus,
we refer to that as a ghost, a meniscus.
And when you see on the axial images, the absence of
that portion of the anterior horn, of the lateral meniscus.

So why is this not a speckled appearance due
to the ACL insertion?
Because we've migrated several slices away from the notch
and we still have this appearance,
and that represents this gap in the anterior horn
of the lateral meniscus.
So a radial tear here.
So look for the cleft, the truncated triangle
and the ghost meniscus.
Those are supportive evidence that you're dealing
with a radial tear.

Importantly, root tears must be diagnosed
and we as a radiologist are the ones
who make that diagnosis.
It's a very difficult diagnosis to make arthroscopically and a very difficult diagnosis
to make on clinical exam.
So we can be extremely helpful in recognizing root tears.
If you have a patient that has meniscus extrusion,
so hanging over the edge of the condyles,
what you're looking for is a presence
of osteoarthrosis typically and osteophyte formation
and the loss of the cartilage.
And that kind of squeezes the meniscus out.
However, there's another cause for meniscal extrusion
and it's this, it's the root tears.
So if you see the meniscus hanging over the edge
and you have evidence of arthrosis,
that might be the cause.
But you still have to pay very close attention
to the meniscus attachment at the root.
Let me show you what that means.

So a normal posterior horn of the medial meniscus,
and then this is a patient with a root tear.
Look at the signal intensity.
And again, I think in a busy practice when you're doing a
lot of different things, these might be more easily overlooked, increase your sensitivity
to recognizing that this is abnormal in signal intensity.
Looks very much like a radial tear that we just described,
except for the location is important.
When you look at the coronal images, the meniscus
root attachment is gone.
Comparing that to the patient's medial side, lateral side,
you have the insertion of the root of the meniscus as nice
and low in signal intensity at the
posterior aspect of the joint.
One way to recognize on the coronal images
that you're at the posterior joint
besides sort of sliding through
and looking at your images on the monitor, is
that there is no bony cross here.
That would be what we would see in the notch.
We have condyle
and condyle, so we're way pretty far posterior.
And then muscle tissue intervening, so that we would expect
to find the root attachments.
At this point here you see the increased signal intensity
of the joint fluid where we would expect then the media
meniscus to be attaching at that root interface.

So this is what it looks like on the sagittal image.
And here we have the gap on the coronal images.
Another example here, a little bit more graphic,
you can see there's a little bit of extrusion
of the posterior horn, of the medial meniscus.
A large gap at where we would expect to find the attachment.
Look again at the posterior horn of the lateral meniscus,
nice and low in signal all the way
to the attachment posteriorly.
So this has lost its hoop strength with a slice right here.
This is basically going to slingshot out
and be extruded once it's extruded.
Now it's not providing the necessary shock absorbing capabilities
that we need within that joint space.
And that leads to then progression of osteoarthrosis
with articular cartilage loss
and subsequently the development of joint space narrowing
on the tal images in this space, you can see that
as we go more toward the notch,
we've lost the normal appearance of the posterior horn,
of the medial meniscus.
And here's the gap.
We would expect this nice c shaved low signal
to be contiguous all the way to its insertion site.
So very important to recognize then those root attachments and root tears.

Normal posterior horn of the medial meniscus adjacent slice,
normal posterior horn of the medial meniscus.
Now look what happened to that signal intensity
of the posterior horn gray.
Really the configuration
of the meniscus itself is abnormal.
We look at the coronal images
and you can see the gap in that posterior horn.
The normal hoop strength will be lost
and the meniscus will hang out over the edge of the condyle.
And again, not providing the normal shock absorbing properties
that we would have in the joint space.
This happens to be nicely demonstrated on the axial images
as a gap in the posterior horn of the medial meniscus.

Body of the Meniscus

So now let's talk about the body of the meniscus.
We take a sagittal slice through the body of the meniscus.
We get this slab of meniscal tissue.
So unlike the anterior posterior horn,
which look like two separate and distinct triangles,
we have a more rectangular appearance
to the body of the meniscus.
So there are a few things that can go wrong with the body
of the meniscus, and I'll address them here.
Very important for us to assess the first
and second slices of the body of the meniscus.

So here we have a nice low signal, uniformly low signal,
contiguous slab of meniscal tissue.
When we don't have a nice low signal rectangular piece
of tissue and we are suspecting deficient body segments,
then we have to look at where that deficiency might be.
We might be dealing with a flipped meniscus within
the medial gutter.
We might be dealing with a bucket handle tear,
in which case we have to assess
for the meniscal tissue somewhere around the joint space.

So let's look at this case here.
It looks like there's a defect in the superior aspect
of the body segment,
and yet when we look at this adjacent image,
that's the meniscal tissue.
So what has happened here is the undersurface
of this meniscal tissue has been torn,
is now flipped into the medial gutter.
And what we are looking at on this image then is the
buckling in or that concave appearance now from the loss
of the meniscal tissue underneath
that mimicking then a divot out of the superior surface
when in fact the problem is the undersurface.
And this is our first sagittal slice
and who really pays much attention to what's going on there.
But in fact, that's the meniscal tissue in the gutter.
What we can see in the same case is the meniscal tissue on
the coronal images deep to the medial collateral ligament.
Normally we wouldn't have anything
but the attachment of the MCL to the underlying bone,
but we have a piece of meniscal tissue that is insinuated
between the bone and the MCL seen on the coronal
and the axial images.
And you can see by this drawing that it's a result
of the undersurface of the meniscus tearing,
flipping into the gutter.
And I can tell you that this is difficult
to see at arthroscopy.
So once again, as radiologists, we have the opportunity
to raise this pathology to the referring clinician so
that they can get the patient in for arthroscopic treatment
of this meniscal abnormality.

Here's another example where the undersurface of the body
of the meniscus is torn,
and we would expect to find that then in the medial gutter.
So look at those slabs of meniscal tissue
to help you identify if there is a deficiency in the body
segments, and then be on the hunt for where
that meniscal tissue may arise.
And here we can see it in this case,
in the medial gutter once again from the undersurface
of the body of that medial meniscus.

In bucket handle tears, we have heard more about,
it's a little bit of a sexier tear, so to speak,
but it's a vertical longitudinal tear that is
actually easily overlooked.
And the reason it's easily overlooked is we're not paying
enough attention to the body segments
and the appearance of the body segments when we slice
through them sagittal.
And so therefore, we're not looking at the extra meniscal
tissue around the joint space.
It's said to represent about 10% of all meniscal tears.
They are frequently overlooked.
We have to increase our ability
and our sensitivity to recognizing these
extremely clinically important
because that flipped meniscal tissue can get caught up
anywhere in the joint space and cause locking.
And that becomes problematic
and almost emergent for the patients
to get their knees unlocked.
And it requires arthroscopy for removal
and debridement of the residual meniscal tissue.
And you can see how it gets its name this
vertical longitudinal tear.
And then this being the meniscal tissue flips,
typically into the notch can certainly flip anterior
and resemble two anterior horns
or can flip posterior representing a very
large posterior horn.
And the way that you would recognize any of
that is looking at the deficiency of the body segments.

So here we have then what we should see,
normal rectangular low signal.
And what we see in this image is a little bit
of undersurface abnormality.
And by the third image we've got blunted edges
of the anterior and posterior horn.
Remember, these are supposed to be symmetric triangles on the medial side.
The posterior horn is slightly larger than the anterior horn
on the lateral side.
The posterior horn
and the anterior horn are similar in size.
That's another tip off to you that you might be dealing
with a pathologic process.
If you see on the medial side
that the posterior horn is similar in size
to the anterior horn, you need to be on the HUD
for meniscal tissue because the posterior horn should be
larger than the anterior horn.
So those are some helpful clues in
recognizing meniscal pathology.
And here we have the bucket handle tear.
The handle is flipped into the notch underneath the PCL one
of the findings we see of that double PCL sign.

Now, this is not a meniscal meniscal ligament
that I presented to you earlier.
We're not gonna be able to track this across the joint
to find the contiguous low signal structure
that represents the meniscal meniscal ligament.
Instead, what we see is deficient body tissue
that represents the handle of the bucket handle tear.
Another example here, we have a slab of meniscal tissue.
As we continue to access the joint going toward the notch, we see a large gap
between the anterior and posterior horn.
And in fact, the anterior horn is blunted
and not triangular and configuration.
When we look at the coronal image, we can see
that there is an extra piece of meniscal tissue.
Here is the PCL, the anterior cruciate ligament.
And then this structure here,
this is not the root attachment of the posterior horn,
of the medial meniscus
because remember the root attachment
is far posterior in the joint space
where we would see then just condyle condyle
and muscle tissue.
Here we have the bony bridge and we're looking at the notch.
That's not where we would typically
find the root attachment.
And so we're looking at the handle of the bucket handle tear
and a nice demonstration of the double PCL sign.

Meniscocapsular Separation

And then another entity that's important for us
to recognize is, again, we bring this to the attention
of the referring clinicians, the meniscocapsular separation.
Typically, we are the first ones who have access to making
that diagnosis.
Fluid is interposed between the meniscus
and the joint capsule, the undersurface
of the medial collateral ligament.
We look for increased distance
between the meniscus and the capsule.
That's fluid signal in nature.
It's important because the meniscocapsular
interface is vascular.
And if that diagnosis is not made, then
that becomes then an avascular zone over time
and can lead to chronic joint line symptoms.
So once that vascular interface is reposed, either
through immobilization
or by putting a stitch in that location,
then you can reattach that vascular supply to the periphery
of the meniscus.
So real important for us to be able to make that diagnosis.

So look in the looking at the posterior horn
of the medial meniscus
and the interface with the capsule,
you can see fluid signal then between the meniscus
and the capsule, a meniscus capsular separation.
Now some would look at that image
and say, well, why isn't that a peripheral tear?
And in fact, it could be classified as a peripheral tear.
The most important thing to recognize is its presence,
because even still a peripheral tear in this location is a
vascular interface and it needs to be addressed.
So whether you wanna call it a peripheral tear
or a meniscocapsular separation, call it something
that alerts the clinicians to that particular location
because they want to address that so
that the patient has a normal function of that meniscus.
And no pain on a joint line imaging examination.

So another example of meniscocapsular separation fluid
signal between the posterior horn and the joint capsule.
This vertically oriented signal, again, could be classified as a peripheral tear.
We're looking at bone contusions
of the medial femoral condyle,
posterior medial tibial plateau.
This is a patient who sustained an
anterior cruciate ligament tear.
So we have contusions on the opposite side of the knee.
I didn't show them to you for this example.
This is the what has been described
as contracoup contusion pattern on the relocation
of medial femoral condyle, medial tibial plateau
as they kind of bang against each other.
And the result is the meniscus gets squeezed in
that situation leading to a peripheral tear.
Remember, in the setting of anterior cruciate ligaments,
you're gonna make a sweep around the joint
for peripheral tears
and tears at the posterior horn of the lateral meniscus.
In this example, nice fluid signal demonstrated
with separation between the meniscus
and the under surface of the MCL or the joint capsule.

So a pretty easy diagnosis here.
What you need to have is a coronal T two weighted image
to be able to see fluid signal deep to the MCL.
And it's much easier to identify if
that coronal image is in fact fat suppressed,
making the fluid much more conspicuous
and a much easier diagnosis to make.

Conclusion on Meniscal Pathology

So in conclusion of recognizing the pathology around the,
the knee, in particular the meniscus, that our role
as radiologists is hugely important in helping
to direct the care that the patient will ultimately get.
Many of the meniscal tears that
that I discussed today are difficult to see at arthroscopy.
And so we really can help to a steer the patient in the right direction,
evaluate contiguous images for the posterior horn
of the lateral meniscus to make sure you're not dealing
with a pseudo tear versus true pathology.
Assess the body segment,
particularly those first couple of slices.
First slice. Usually it becomes very important in seeing
whether you're dealing with an intact body segment
or if you've got a sneak preview at an undersurface tear
and a meniscus fragment
that's flipped into the gutter
and assess the root of the meniscus in the setting
of extruded menisci.
So if you see the meniscus hanging out over the edge,
even if you see that the patient has osteoarthrosis,
don't just assume that the meniscus is out there
because the patient has joint line cartilage loss
and osteophyte formation, and
therefore the meniscus is extruded.
Pay close attention to that root attachment to see if
that's the cause of the extrusion.

Pediatric Knee Imaging

Now I wanna show you,
I was at a conference earlier in this week,
the International Skeletal Society,
and I was looking, I was part
of the pediatric session
and I wanted to present this to you as something
that we probably all have seen.
And we are all doing more
and more pediatric imaging as these kids are getting more
and more involved in sports at younger ages
and even sports specific.
So they're playing the same sport throughout the entire year
as opposed to mixing it up
and playing different sports.
So more and more kids are coming to us for imaging,
and as I learned through the sessions of pediatric imaging,
p the pediatric population is not just little adults
and the pediatricians are very careful to say
that we're not just looking at small skeletons that they get and suffer some unique injuries.

So this is a patient had anterior knee pain
after a basketball game
and the arrow is pointing to the finding there,
and it's a small fragment of bone.
So if you see this abnormality, recommend an Mr.
Be thankful that you saw the abnormality.
Be thankful that you might even be able
to make the diagnosis.
But this patient, this child needs to have an MRI.
And that's because the MRI will then clearly depict the
integrity of the rest of the extensor mechanism
and will show then that AULs of that osteochondral fragment
for this injury.

Now if you see an x-ray that looks like this with
that finding at the inferior pole of the patella, that kind
of mimics Cindy Larson Johansson.
So getting back to some points
that were made earlier today in by Dr. Webb, it's
so nice to have a comparison film
because the early film of this patient showed that
as a flake fracture off the undersurface
or the inferior pole of the patella.
And what we're looking at is a patella sleeve injury.
This is very important to diagnose.
So the patient gets proper treatment.
It's basically an osteochondral fracture.
It occurs an eight to 12-year-old children affecting the inferior pole of the patella.
And because of the articular cartilage
and the attachment of the reticulum, that needs
to be reposed.
So we definitely have to bring that
to the attention of the clinicians.
It's generally due to a high impact jumping sports due
to the eccentric contraction
of the quadriceps on a fixed knee.
And you just basically get a sudden avulsion fracture of the inferior pole
of the patella on imaging.
You can see the small bone fragment,
you might not see it at all,
particularly if you just pulled off a little
piece of the cartilage.
You may find a high riding patella
or possibly a joint effusion.
But Mr is absolutely the study of choice just
to assess the degree of chondral injury as well as
to determine coexistent extensor mechanism pathology.
So if you see that little flake fracture, just go ahead
and make sure that that child gets MRI follow up.

This is a cheerleader who presented
with chronic pain in her knee.
The x-rays were interpreted as normal
and I think that they are, but
because of her chronic pain
and the underwhelming x-rays, she went on to have an MRI.
And what you see on this MRI is important
for us to understand.

So on the fat suppressed T two weighted images,
we have bone marrow edema in the epiphysis
as well as the metaphysis.
Don't really see any edema pattern though within the fsis.
You can see also on the T one weighted images, a little bit
of low signal representing that edema pattern.
Similarly, we can see it on the coronal images as well
as the axial images,
but look at where that edema pattern is.
With respect to the bones itself.
It is toward the central aspect of the growth plate.
And this is focal per fial edema.
And I know I have called that pathologic in the past.
I don't spend a whole lot of time reading the pediatric
literature, but there was a very nice article a couple
of years ago talking about focal peral edema or FO
and the FO zone.

So yet another set of initials that we need to know
it occurs in the closing ssis.
It's not to be mistaken for an abnormality,
requires no invasive diagnostic procedure,
no imaging follow up and may be associated with pain.
And it's said to be due to the closing of the fsis.
So it's why we see that kind of edema pattern at the ages of skeletal maturation.
So as the fess is starting to close,
we can see these folk zones.
The bone marrow edema is centered at the central portion
of the closing ssis,
and this is most often described in the knee.
So if you're looking at a child, you see that appearance,
feel confident in calling that a FO zone at finding it's not even an abnormality.

So once you recognize this
and you're comfortable, these areas occur in the central
portion as the fey are closing.
So if you see it more toward the anterior posterior aspect,
it's probably not a folk zone and could be true pathology
and make sure you're not looking at assault
or Harris injury.
But this is at the central aspect
and it's presumed due to the early closure
of the growth plates.

This is a companion case as a child who was playing soccer and had some pain came for MR.
Imaging, recognized the location
of this bone marrow edema pattern on both the T one
and the T two weight images.
This child went on to have CT as well.
What you see on the CT is sclerosis in the area where
that growth plate is first starting to close.
So comfortable recognizing this in the central portion of the growth plate.
Again, if you happen to do ct, which you don't need to,
this is virtually pathic monic on Mr.
I'm bringing it to your attention because it certainly
wasn't pathic monic for me the first time that I saw it.
So perhaps now if you see this in your practice,
you'll recognize this as a FO zone and decrease everybody's anxiety level
that this is not something that needs biopsy
or additional imaging.
Thank you so much for your attention.