Hi, this is Dr. Centeno, and I'd like
to go over today how to read your knee MRI,
focus on the meniscus.
I have a whole series of these and reading a knee
MRI requires some knowledge of individual areas.
So this one's going to focus on the meniscus.
So this video isn't meant as a substitute for radiology report
or your doctor's opinion, it's just
to educate you about what's on that image.
So what does a meniscus do?
A meniscus is a shock absorber and a spacer.
So basically it's the shock absorber and the spacer
inside your knee.
But before we start, it's very important
that you understand that there is no evidence
that in middle aged or elderly patients
a meniscus tear causes symptoms.
Now, you might be very surprised to hear about that.
But there's very good research that shows that meniscus tears
in that age group are just as common as grey hair.
So we can't look at a meniscus tear in a MRI
and say, ah-ha, that's causing your pain in middle aged
or elderly patients.
So be very careful about someone who just looks at your image
and says that's what's causing your pain because there
is no science to support that.
In addition, there's no evidence that operating
on a meniscus tear-- with or without arthritis--
is effective.
Again, you might be very surprised to hear that.
But multiple, high quality studies have now
shown that operating on a meniscus tear isn't effective,
doesn't help.
So again, just to be absolutely clear on that point,
we're going to talk today about meniscus tears
but the concept of operating on them
has not been supported in the science.
A MRI is a 3D picture that slices through things
and there's three planes, sagittal, coronal, an axial.
And these are what the three planes look like.
The coronal plane is this front plane.
The sagittal plane is the side plane.
And the axial plane is the side and half
view or the looking from the top or from the bottom plane.
And on your MRI, this is what they'll look like.
This is what a knee axial looks like.
This is what this sagittal looks like.
And this is what the coronal looks like.
And again, just remember that you're slicing through a three
dimensional structure.
The easiest way to find the meniscus
is on the sagittal or coronal images.
This is what the coronal will look like.
This is what the sagittal will look like.
Look for a dark, triangle shaped structure.
So you see here this triangle shaped structure, here.
This one here.
And this one here.
So on the coronal or the sagittal,
the meniscus will always look like a triangle.
Or at least the normal meniscus.
And I'm going to highlight those triangles right here.
Now let's read an image.
I'm going to pop out of this program
and go into the image program.
This image has been donated by one of our patients
who has allowed us to use her name.
And you'll see here that I'm starting with this one up top,
which is the coronal image.
And its where the bone is dark.
And I'm just going to scroll through this image
and I see the patella there-- or the kneecap.
And then I start to see the main knee bone's come in.
And I see this meniscus coming in right here-- this triangle.
And as I go back further I'm going
to see this other meniscus coming in
and this other triangle.
And this is-- over here-- the middle of the meniscus.
And as I go through here, you will
see I can get through the entire meniscus.
So as I scroll back to front-- this is from the back.
Now I go towards the front.
I'm scrolling through the meniscus
and I see a few things here.
I can see that this meniscus is uniformly dark.
And this one's got a light bit in it--
sort of a horizontal, white line.
And what I'm seeing there is a tear in this meniscus.
And you can always tell the inside from the outside here.
The outside is going to have this extra bone
on the side-- or the fibula.
This is the outside or lateral.
And the other side is the inside or medial.
So what I'm seeing here is this light bit
inside this meniscus is a tear in the medial meniscus.
So now I'm going to go to the side view
so we can take a quick look at what the side view looks like.
And again, I'm starting from the inside here.
These always start from the inside.
And as I go through I'm going to start
to see the triangles of the meniscus come in.
This white stuff happens to be fluid in this patient.
And I'm going to see, again, this meniscus upfront looks
like a nice, uniformly dark triangle but this meniscus
in the back has got some white stuff in it
and that means that there's some tearing, which we saw before.
Again, this is the medial meniscus
and now I'm in the back so I know
it's the posterior-- or the back- medial meniscus.
And then I'm going to go to the middle
where I see the PCL and ACL ligaments-- that's the middle.
And then as I keep going across, I'm
going to now go to the outside-- the lateral meniscus.
And I see my little triangles coming in here.
And triangle and triangle.
And those look pretty good.
They're uniformly dark.
So now let's switch back to the presentation
so we can take a look at what some abnormal meniscus
tissue looks like.
So this is an example of a simple horizontal meniscus
tear.
You can see here a horizontal light line
in the dark triangle, on the sagittal.
And this is on this sagittal image where the bone is bright.
The cartilage is this grey color.
And the meniscus-- on this image as well-- is going to be dark.
This is a simple horizontal meniscus
tear on the front-- or the coronal view.
You can see here the red arrow points
to a white line that goes all the way through this meniscus.
Again, a normal meniscus is uniformly dark.
This white line means a tear.
A bucket handle tear-- the best way
to understand a bucket handle tear
is to look at what it shows up like when
you're looking from the top.
So this is the normal meniscus on this side--
you can see it's shaped like a C. But on this side,
you see a rent or a tear in the meniscus.
And you see that one part of the meniscus
is actually moved inward opening up the tear.
So when you're looking at this-- you've
got to realize when you are looking
at this on a cross section, you're
slicing across this as so.
You're going to see one piece of the meniscus over here
and one piece of the meniscus over there.
That's a bucket handle tear.
That means that one piece of the meniscus
has separated from the other one.
And if we were to look at in three dimensions,
it would look like this.
A displaced meniscus with a tear is something else
you should be on the lookout for because this
is very common when we're in a situation
where the patient has had prior surgery.
Basically, the surgeons usually take out
this part of the meniscus inside and that allows the meniscus
to spit outside the joint.
So you can see this meniscus is a nice, dark triangle
and it's contained within the joint.
And this meniscus is now outside the joint--
this is where the joint ends.
It's been spit outside the joint and it's
got this light area in it so it's torn and displaced.
What does that mean.
Well, this meniscus is acting as a nice shock absorber
and this meniscus is not.
A displaced meniscus with bone spurs--
you can see here that both of these meniscus's are
kind of pushed out of the joint a little bit.
This one more so than this one but you
can see this meniscus actually is pushed outside the joint.
And little spurs have formed here and there.
Now these are what I call functional bone spurs.
These bone spurs shouldn't be taken off
because if you take them off surgically-- unless they're
causing some other problem-- you're
going to end up creating less cushioning for the joint.
Right now this meniscus has begun
to spit outside the joint.
The body formed these spurs to take
advantage of that new position.
And it's still a valid shock absorber.
But if we take those bone spurs off
we're going to have problems.
A displaced and macerated meniscus is right here.
This is someone who's got no cartilage on this compartment
right here.
You can see that this has a normal triangle, dark meniscus.
There's a little bit of grey stuff at the end of the dark
bone here, which is thinning cartilage.
But this side has very little cartilage.
The bone is bright, which means that the bone is
getting bruised and probably small fractures
within the bone.
And we can see here that the meniscus has pushed out
of the joint.
It has lots of white in it so its macerated meaning it
has lots of different tears.
And this is a macerated meniscus with bone cysts.
So this is what will happen in the long run
if the meniscus is not there.
The bone will actually die off, which
is this little cyst right here.
And on these before images you can see a very nasty
looking meniscus.
It doesn't really look like a meniscus.
You can see the normal one over here-- a nice, dark triangle.
You can see what's left of this one after surgery-- not much.
And then after a stem cell treatment,
you can see here that the meniscus actually
has some form to it.
It's not normal by any stretch of the imagination
but it has some form to it.
And you can see that the bone cyst went
from looking like this to looking
like that-- or much, much less.
On this slide we see a macerated meniscus with bone cysts
from the side view-- or the saggital.
So we see here we have some bone cysts here.
Again, the same meniscus we're looking
at now from the side-- it looks almost like an untamed dragon.
And over here, we can see after the stem cell treatment
it has much better form to it.
And those little bone cysts go away.
And then an absent meniscus with no cartilage whatsoever.
We can see the nice, normal triangle over here.
This one is completely gone.
And there's not a meniscus and there's no cartilage there
either.
Well, thanks for watching.
I hope this gives you some sense of what's on your knee MRI.
I always find that an empowered patient is actually
the best patient.
Because an empowered patient that
knows what they're looking at, that
knows what all of this stuff means
is one that actually helps the doctor figure out what the best
options are for that patient.
So thank you for listening.