0:00

Now this is a very important slide

0:02

and we'll be covering it several times

0:04

during this particular lecture

0:06

because I think when we deal with trying to establish a

0:11

specific diagnosis for an abnormality

0:13

of the sacroiliac joint,

0:15

the first step is the distribution of the process.

0:19

Is the process bilateral?

0:21

And if so, is it symmetrical or asymmetrical

0:24

or is it unilateral?

0:26

And although there is variability in the distribution,

0:30

as you can see from this particular table

0:33

or chart, I will show you the most classic distributions

0:36

as we progress through this initial lecture.

0:41

Let's first talk about osteoarthrosis.

0:43

In our practice, we generally use this term osis rather than

0:48

itis who describe degenerative disease

0:50

of a synovium line joint and hence the sacroiliac joint.

0:55

We often see osteoarthrosis of the sacroiliac joint.

0:59

It dominates in middle aged and elderly persons.

1:02

And most characteristically it's bilateral.

1:05

It may be symmetrical or it may be asymmetrical.

1:09

So let's look at this.

1:11

I wanted to point out using this coronal section

1:15

of the sacroiliac region on your left

1:17

and a radiograph, there are two degenerative processes

1:21

that involve the sacral iliac interosseous space.

1:26

When we're talking about an abnormality

1:28

of the ligamentous portions of that particular region,

1:31

we talk about a degenerative enteropathy.

1:35

And as shown here, particularly in this image on your left,

1:40

what we may see would be some bone sclerosis

1:43

and ligament deification.

1:45

And in some cases you may even see fusion bony fusion

1:50

of the ligament disc space that would be in the region.

1:54

Up here, when we talk about osteoarthrosis,

1:57

we're talking about abnormality in the lower

1:59

portion of the joint.

2:01

This the synovial, the true synovial joint.

2:05

And here there are a number of abnormalities that we see.

2:08

And most of you listening, if you are middle aged

2:11

and elderly, you will in fact have this disorder.

2:15

That's the bad news.

2:16

The good news is it's generally asymptomatic.

2:20

The findings that you can see include joint space narrowing.

2:23

You can see that on the right bone sclerosis, which

2:27

dominates again on the ileal side initially very linear.

2:32

Later on it becomes patchy

2:33

and more widespread vacuum phenomena.

2:37

That is gas, mainly nitrogen present within the joint.

2:41

That was emphasized early on in descriptions of osteoporosis

2:45

of this joint and osteophytes.

2:48

And the typical osteophytes are not hard to recognize.

2:51

They hang down from the inferior aspect

2:54

of the true S sacroiliac joint as you would expect.

2:58

But occasionally the osteophytes looked funny

3:01

and I can remember this particular case

3:04

or one just like that.

3:05

Early on when I became a faculty member at UCSD

3:11

being well trained

3:12

and rotating through Sloan Memorial Hospital, I saw a lot

3:16

of cancers and I remember carcinoma to prostate,

3:19

metastatic to bone.

3:21

So I made the mistake initially

3:23

of calling something like this prostate mets.

3:26

But when you study this with CT

3:28

or with mr, you can see that what you're looking at

3:31

what composes this radio dense region is a combination

3:36

of bone sclerosis and a bridging anterior osteophyte.

3:40

And typically it occurs at the very top

3:43

of the synovial joint, the synovium lined sacroiliac joint.

3:50

This is what degenerative osteopathy looks like, again,

3:53

in a specimen on your uh, left

3:55

and in a radiograph on your right.

3:58

And in this particular case,

4:00

you can see well-defined ligamentous ossification

4:04

crossing the space between sacro manum.

4:08

Now a word of caution.

4:10

Certain disease processes, particularly the

4:13

spondyloarthropathies can produce enthesitis in this region.

4:18

And you'll get ill-defined regions of bone sclerosis

4:22

above the synovium lined joint shown here.

4:26

And this joint, by the way, shows osteoarthrosis.