0:00

So now, let's take a case.

0:02

Here are two axial images.

0:06

One, the one on your left is...

0:10

The one on your left is T2,

0:12

and the one on your right is a fat-suppressed 3D.

0:16

We're going to work our way down to the meniscal level.

0:19

So we start up high, we go down low,

0:23

and we see a rather bizarre looking configuration.

0:26

And I'm going to draw right over the

0:28

top of it right now and blow it up,

0:30

make it a little bigger.

0:35

And we have this structure here,

0:39

which you can see over here.

0:42

And we also have this structure here.

0:45

And what you're looking at are the native meniscus

0:49

and a displaced piece of meniscus that has broken

0:53

off with a gigantic gap in the center.

0:58

Don't believe me?

0:59

Let's look at our most favorite nation projection

1:04

for a bucket handle tear, which is the coronal.

1:06

Let's go to the coronal and scroll it.

1:10

Now, we said when you have a bucket handle tear,

1:12

you're going to have a rim.

1:14

And here is our rim.

1:17

It's a pretty small rim, isn't it?

1:19

We might measure the rim from its

1:21

outer third to its inner tip,

1:25

and that might be only two or 3 mm,

1:27

making it very difficult to sew to.

1:29

So we have a very tiny rim.

1:31

We said there's going to be a giant hole.

1:34

Well, here's your giant hole right here.

1:37

That's your giant hole.

1:39

And we said we're going to have a piece that is

1:44

displaced into the center of the knee underneath

1:46

the posterior cruciate ligament.

1:48

There is the piece displaced right underneath

1:52

the posterior cruciate ligament.

1:53

There's the posterior cruciate ligament.

1:55

There's the piece immediately underneath it,

1:58

the so called double pcl sign.

2:01

Now let's scroll it.

2:03

We go to the back,

2:05

and all the way in the back,

2:07

we're actually ripped off.

2:08

We're missing a piece of the posteromedial corner.

2:11

There's the meniscus with the meniscus root.

2:14

Let's go forward.

2:15

Meniscus got a little vertical tear in it at the

2:19

capsule. There's a fragment. Let's keep going.

2:23

Meniscus fragment. Meniscus fragment.

2:27

Meniscus fragment. Meniscus fragment.

2:30

And now they're going to come back together again.

2:32

And there they are.

2:33

They finally come back together all the way in

2:35

the front. Now, what else can simulate this?

2:39

There are two very important simulators

2:41

of a bucket handle tear.

2:43

One is an anterior large accessory bundle

2:49

of the pcl that swings forward like this

2:54

and inserts on the inside edge of

2:58

the medial femoral condyle.

3:00

Now, how do you know that's not a fragment?

3:02

Because it's going to be dark,

3:03

like a ligament or like a meniscus,

3:06

because you can follow it right back

3:07

to the PCO when you scroll it.

3:10

That is a major cause of misdiagnosis

3:14

of bucket handle tear,

3:15

especially after someone's had a menacectomy,

3:17

because now the meniscus looks small.

3:19

You think, where'd it go?

3:20

You find this extra ligament,

3:22

you in your mind's eye, connect the two,

3:24

and you think, you got a bucket handle tear.

3:26

You don't.

3:26

The meniscus have to come back together

3:30

again or at least oppose each other.

3:32

The other major cause of misdiagnosis

3:36

of a discoid meniscus is this.

3:39

If you've got a very tightly c shaped meniscus and

3:44

you perform a coronal projection on at least a

3:47

couple of cuts, you're going to get a meniscus,

3:50

then a hole, then a meniscus.

3:52

But that hole is just a normal curve.

3:55

That's the normal cartilage surface.

3:57

And if you have a little cinovitis in there,

3:59

it might have a little fluid with it.

4:00

So it's going to look like a little hole

4:02

right there. And then on the next cut,

4:04

you might have the same thing,

4:05

but then it suddenly goes away,

4:06

it looks normal again.

4:08

And then you go up to the next cut,

4:10

and all you see is a triangle,

4:11

and it never separates,

4:13

maybe from more than two cuts.

4:15

So when you have a very tight c shaped meniscus

4:18

that can simulate a bucket handle tear.

4:22

Finally, let me just show you the sagittal.

4:25

Just for completion's sake. Here's our sagittal.

4:29

We'll blow it up a little bit.

4:33

Here's our lateral meniscus.

4:35

Let's go over to the medial side.

4:37

We said that we were going to have a rectangular

4:39

shaped or linear shaped structure that's extra.

4:42

Well, here it is right here.

4:44

This one's a little arc shaped.

4:46

It sits right underneath the PCL,

4:48

the so called double PCl sign of a bucket handle

4:52

tear. And we go over to our medial meniscus,

4:54

and our rim is pretty darn small.

4:56

How does our rim look?

4:58

Not so good.

4:59

If we look very carefully.

5:01

There's a big vertical tear in the back of our

5:04

rim. There's another small vertical tear.

5:06

There's some complex signal posteriorly.

5:08

There's some complex signal anteriorly.

5:12

Let's keep going. Oh,

5:13

there's two structures there, just like we said,

5:16

double anterior meniscus sign.

5:19

Because a portion of this bucket handle

5:23

tear has pushed forward in fact,

5:26

the portion that's pushed forward is here.

5:28

The native meniscus is shoved

5:30

all the way in the front.

5:31

So in this example,

5:33

you've got something that looks like this.

5:38

You've got your bucket that's pushed forward.

5:43

There's your native meniscus,

5:45

and here's your big hole.

5:47

So there is your double meniscus sign.

5:51

Native meniscus shoved anteriorly,

5:53

bucket handle fragment pushed anteriorly.

5:56

Double anterior horn sign of a bucket handle tear.

6:00

So that concludes our discussion of bucket

6:02

handle tears. You got the central type.

6:04

You've got the anterior extended type.

6:06

You got the posterior extended type.

6:08

You got the complete free fragment type.

6:11

The bucket fragment can twist, it can migrate,

6:15

but when it migrates,

6:16

it usually does so anteriorly.

6:18

The classic bucket will go underneath

6:20

the posterior cruciate ligament.

6:22

It's important to assess the rim thickness and

6:25

whether the fragment that you're trying

6:27

to sew to itself also has a tear.

6:30

And one final caveat.

6:32

People that get bucket handle tears,

6:34

they usually have some form of knee laxity.

6:38

The most common form, ACL deficiency.

6:41

This patient had a graft.

6:43

The graft is attenuated proximally.

6:46

In fact, it's torn as it enters the femur.

6:48

This is an ACL deficiency.

6:50

They go together like soup and sandwich.

6:52

Bucket handle tear and ACl deficiency,

6:57

very common.

7:00

Medial is more common. It's about 60 40.

7:03

Yeah, not uncommon. It.