0:00

Here is a great example of a

0:04

condition called jersey finger.

0:07

And it's not something that

0:10

happens to people from New Jersey.

0:12

It's something that happens typically in

0:15

American football when somebody's

0:19

reaching out to make a tackle and their

0:21

finger gets caught in somebody's jersey.

0:24

And as the person darts away or the hand

0:28

is pulled back, that finger gets caught

0:30

in the jersey and it causes an avulsion

0:34

of the flexor digitorum profundus tendon.

0:38

And what I love about this case is it

0:39

actually shows it at the most commonly

0:43

located area, which is your fourth finger.

0:48

So this is your thumb, one, two, three, four.

0:52

So this is where the abnormality is happening.

0:55

You can see all the fluid within

0:57

the tendon sheath, all the edema.

0:59

That's actually going to be much

1:00

better shown on the sagittal sequences.

1:03

But I just want to go over a little

1:05

bit of anatomy here, which I think

1:06

is very instructive and helpful.

1:08

You see these little paired

1:09

tendons right here?

1:11

That's actually the superficial, uh, flexor

1:15

digitorum superficialis, which comes and

1:16

attaches right here at the middle phalanx.

1:21

And let's look at that on the sagittal images.

1:24

If we look at this right here, so

1:26

here is one coming attaching one side

1:29

here, see that, at the middle phalanx.

1:32

And the other sort of limb of it

1:36

attaching right here also at the

1:38

middle phalanx of the fourth digit.

1:41

So it sort of splits like a forked

1:43

tongue to have two separate attachments.

1:46

Here's the coronal view again.

1:48

These two separate attachments at the

1:50

middle aspect of your middle phalanx.

1:53

Let's look at now.

1:55

The adjacent finger, which is normal.

1:57

So, let's see if we can

1:58

find those structures again.

1:59

And here it is.

2:00

Here are the two paired structures.

2:03

These two structures here, the superficialis,

2:04

flexor digitorum superficialis, correspond

2:07

to these two structures over here.

2:10

But, what's the difference?

2:13

The difference is, on this side, you see

2:15

something else in the middle, extending up.

2:20

Here it is, extending up, and

2:21

attaching to the very distal aspect.

2:25

Or the distal phalanx of that finger.

2:28

Over here, we're not seeing any

2:31

structure between those two structures.

2:34

It's just blank.

2:35

And up here, you're seeing

2:36

sort of this gray something.

2:39

Right?

2:39

It's not black.

2:40

Like this structure is over here.

2:42

It's not black.

2:43

Okay?

2:43

So what's happened?

2:45

Well, this tendon, which is the flexor

2:47

digitorum profundus, and let's show you

2:49

that on the sagittal images over here.

2:52

Okay?

2:54

So, there should be another tendon

2:56

over here, coming to attach at the very

2:59

proximal aspect of your distal phalanx.

3:01

So let's show you a normal side, normal finger.

3:05

Here's a normal finger.

3:06

You see there's a tendon right here.

3:08

You see that thing right here?

3:09

That's the flexor digitorum profundus attaching

3:12

to the volar base of your distal phalanx.

3:16

On our abnormal side, nothing there.

3:19

Maybe a little stubbin of something

3:20

gray, but you sort of lose it.

3:23

So where is that tendon?

3:25

Now, if you look way down here, you see this.

3:30

So that tendon has not only torn, but has

3:34

retracted all the way here to the hand.

3:38

So this is a retracted flexor

3:41

digitorum profundus tendon.

3:42

You can actually see it the best.

3:44

On this sequence, which is the sagittal

3:46

fluid-sensitive fat-suppressed sequence,

3:49

the tendon is bunched up over here.

3:50

Again, this is the superficialis.

3:53

The profundus is torn right at this point.

3:56

And all the stuff, this is fluid

3:59

within the tendon sheath of

4:01

your flexor digitorum profundus.

4:02

So this is a great example of a jersey finger.