0:00

This is a ten-year-old.

0:01

He presents with left-sided pain,

0:04

evaluate for H and P at L5-S1 strain,

0:09

radiculitis,

0:11

and he does have a known underlying disorder.

0:14

And let's have a look at the Sagittal images.

0:17

We've got a T2 spin echo on the right,

0:22

got a proton density fat suppression on the left,

0:25

and a T1 in the middle.

0:26

It probably doesn't really matter which one you look

0:28

at, although the L5-S1 abnormality,

0:31

the disc displacement abnormality,

0:34

or herniation is readily apparent.

0:37

But I think you're struck by the character

0:40

of the disc endplate complex.

0:42

Now,

0:42

if you pair this with the Vignette

0:44

on ankylosing Spondylitis,

0:46

in which the vertebrae were slightly convex

0:49

up on each side, in this example,

0:53

they really are very flat.

0:54

You could draw a straight line.

0:56

Now, that's a straight line right there.

0:58

Granted, it dips down a little bit anteriorly,

1:00

but that is typical Platty spondyli,

1:04

and the differential diagnosis for this is really

1:07

extensive. It includes a whole family of dysplasias,

1:12

dwarfisms, connective tissue disorders,

1:16

pseudoconnective tissue disorders,

1:18

metabolic disorders, et cetera.

1:20

So it requires a very long list to dissect out.

1:24

Now,

1:25

a few comments about this case as it

1:27

relates to ankylosing Spondylitis,

1:30

which many of you are adult radiologists

1:32

and probably will see in practice.

1:34

We've already pointed out that the vertebral shape

1:37

is a little strange for ankylosing Spondylitis.

1:41

There's no inflammation in the center of the disc

1:44

endplate complex. So no Anderson lesions,

1:47

no shiny corner sign, no Rominus lesions anteriorly.

1:52

The patient is not fused despite the fact that

1:55

the disc endplate complex is horrendous.

1:58

I mean, every single level is affected.

2:02

The patient is also too young.

2:04

He's ten years old,

2:05

and this disorder started when he was very young,

2:08

much younger than that.

2:09

I believe

2:10

it first manifested itself at about age three.

2:13

So that wouldn't fit at all for

2:15

ankylosing Spondylitis.

2:17

He's got a lot of restricted joint mobility,

2:21

even at the age of ten in the phalanges.

2:24

So that doesn't fit with as,

2:26

even though people with as do get involvement

2:28

of larger and small joints.

2:31

That wouldn't be typical in this age group either.

2:34

Unfortunately,

2:35

this condition was mislabeled and has been

2:39

mislabeled as Jia juvenile idiopathic arthritis

2:43

because Jia patients, formerly known as JRA,

2:46

are rheumatoid factor negative,

2:49

and this patient and other patients like him,

2:52

his brother with the same disease,

2:54

are also rheumatoid factor negative.

2:58

So that leads you down another road.

2:59

Now,

3:00

most of the trainees that I've shown this case to,

3:03

one of their first reactions to it,

3:05

you say what you know, and Scheuermann's disease,

3:09

it's a pretty commonly taught disorder amongst

3:12

residents and fellows and young radiologists.

3:15

It is a form

3:17

of end plate degeneration. It's an osteochondrosis,

3:22

but it has its epicenter kind of higher the upper

3:25

lumbar region and the thoracic region,

3:27

usually five or six levels,

3:30

often not every single level,

3:32

and often not this severe at this young an age.

3:36

And while it is a connective tissue disorder that's

3:39

intrinsic to the disc endplate complex,

3:41

and so is this. Again, this occurs at a younger age.

3:45

It's more severe, it covers more levels.

3:47

And this is known as pseudo rheumatoid arthritis

3:50

because it looks like rheumatoid arthritis.

3:53

It doesn't respond to any of the typical

3:56

rheumatologic therapies,

3:57

responds not at all to steroids,

4:00

not at all to chemotherapeutic agents,

4:02

including methotrexate.

4:05

And frequently you get this very peculiar nest-like

4:08

clustering of chondrocytes in the resting and growth

4:13

cartilage, suggesting that pathogenetically,

4:15

this is a primary disorder of the articular

4:18

cartilage that has an underlying genetic etiology.

4:21

In fact, it does have, we now know,

4:23

a genetic etiology, much like, say,

4:26

the genetic etiology of Ehlers-Danlos

4:29

syndrome that can occur in siblings.

4:32

So I'm showing it not so much for the pseudo

4:34

rheumatoid arthritis, although, remember,

4:36

this is often confused with Jia,

4:39

especially when it presents in the hands and digits.

4:42

But I'm showing it for the Platty spondyli and for

4:46

the factors that make it so much different from

4:50

Ankylosing spondylitis and from Scheuermann's disease.

4:54

Now, one other caveat.

4:56

Sometimes you'll see very severe

4:59

disc and end plate deformity,

5:00

but you'll have what we call fish mouthing,

5:03

where the middle of the end plate bows inward.

5:06

Notice we don't have that here.

5:09

That is typical of bone softening disorders.

5:12

And that kind of puts you in a whole other category

5:15

when you think about osteopenia and osteoporosis,

5:19

especially at a young age.

5:20

And even at a middle age,

5:23

you're thinking about osteoporosis in a

5:25

50-year-old woman. In a ten-year-old,

5:27

you might be thinking of something like osteogenesis

5:29

imperfecta or some other metabolic condition

5:33

that causes bone softening. So remember,

5:37

when you're looking at these cases,

5:38

look at the vertebral shape,

5:40

see if the shape is convex up,

5:42

if it's flat platypondy or convex down,

5:45

or fish mouth.

5:46

And that might help send you in the correct

5:48

direction. Let's look at another one, shall we?