0:00

<v ->I want to turn to the non pressured segment

0:04

of the joint and go back up

0:05

to the hip to point out that the largest osteophytes form

0:12

through endochondral bone formation

0:15

in patients who have osteoarthritis

0:18

and therefore they require cartilage laying down bone.

0:24

So if you look at the pressured portion of the joint

0:27

there's no cartilage remaining.

0:29

If you look elsewhere where there is still a joint lumen

0:33

there is cartilage, and it's that cartilage that lays

0:37

down the marginal osteophytes that are characteristic

0:42

of osteoporosis.

0:44

Now, as you look at this, I want to point

0:46

out something that a lot of people don't recognize,

0:49

but boy has it helped me through the years.

0:52

As the osteophyte forms,

0:55

it buries the original zone

0:57

of calcified cartilage, right there.

1:00

Here's what it looks like in the specimen.

1:02

Here's what it looks like in the specimen radiograph.

1:06

And that tells you where the femoral head was,

1:09

that all of this is a new bone,

1:13

new bone that's formed owing to endochondral bone formation.

1:18

So that even later on, when the bone may fill the

1:21

entire joint lumen, you'll realize that this began

1:26

as asymmetrical loss of joint space, typical of OA.

1:31

And all of the bone forming over here is simply the result

1:35

of an enlarging osteophyte.

1:37

Look for that curve linear line, along the medial aspect

1:42

of the femoral head, and also on the medial aspect

1:45

of the humeral head as well.

1:48

Now, when there are islands of articular cartilage

1:52

that are left behind centrally, central button

1:57

like osteophytes may also form.

2:00

I'm showing you here some examples.

2:03

You can see two images from one example at the top.

2:08

Another image here, and then a specimen

2:11

showing you what a central osteophyte looks like.

2:15

This is button-like, right?

2:18

It can simulate an intra-articular body,

2:22

but it is continuous with the bone.

2:25

Here, there are marginal osteophytes as well.

2:28

And sometimes as with marginal osteophytes,

2:31

a portion of the original zone of calcified cartilage

2:35

may be left behind as that osteophyte has grown.

2:41

Be aware of these central osteophytes

2:43

most commonly seen in the knee and in the hip.

2:49

There's another osteophyte.

2:51

I keep saying things that are my favorites.

2:53

I have a lot of favorites.

2:55

This is one of my favorite osteophytes.

2:57

I call this the curtain osteophyte.

3:00

It grows across the acetabular fossa.

3:03

So if you think of yourself as the femoral head,

3:06

and you're looking toward the acetabular fossa

3:09

early on in a normal hip,

3:11

you're going to see a lot of fat.

3:12

That's the acetabular fat, and then the curtain forms.

3:17

And as that curtain grows,

3:19

that acetabular fat will disappear over time.

3:22

This is what it looks like.

3:24

Note here also another characteristic site,

3:27

foveal osteophytes as well as a marginal osteophytes

3:31

on the femoral head.