0:00

Just to give you an idea of what this looks like.

0:03

Yes, there is a relationship

0:04

with subc chondral insufficiency fractures.

0:07

Typically, the fractures occur below the subcon bone plate.

0:11

I show you that here with an Mr. Case

0:13

and an image, they may merge with it.

0:16

And although it has been suggested that they have a shape

0:19

that is convex to the articular surface, I don't think

0:23

that holds up very well and as a good rule.

0:27

Uh, so I, it hasn't been helpful for me at least.

0:31

Here's another example

0:32

of a subcon insufficiency fracture associated

0:35

with marrow edema extending down from the femoral head

0:39

to involve the femoral neck.

0:42

And then along came another disorder,

0:44

which was an interesting one.

0:46

This was called regional migratory osteoporosis

0:50

or osteopenia.

0:52

It was described in several articles that came out

0:54

of Detroit and uh, uh, Duncan, uh,

0:58

Howard Duncan and his colleagues described this.

1:01

It was a small number of patients

1:03

who had self-limited acute migratory pain involving the

1:08

joints of a lower extremity, not the upper extremity,

1:11

and led to regional osteopenia that was similar to that with

1:17

complex regional pain syndrome or RSDS.

1:21

And here are pictures taken from one

1:23

of those articles showing you the osteopenia

1:27

occurring about the uh, ankle.

1:30

And then, uh, two years apart, the bone mineral looks good.

1:35

So similar to trans osteopenia of the, uh,

1:39

about the hip involving the femoral head,

1:42

but now involving other regions

1:44

and perhaps migrating from one region to another.

1:49

So if we look at the early characteristics of

1:52

what was called regional migratory osteoporosis,

1:56

men more often than women, third to fifth decade of life,

2:00

predominating almost isolated to the lower extremity at

2:05

or distal to the hip.

2:06

And I show you one example. This is an old case of ours.

2:10

We can look at stir imaging here.

2:12

Initial involvement of the femoral head that went away,

2:16

then the proximal tibia that went away,

2:19

and then involvement here involving the tarsal bones.

2:22

Okay? So features similar to transient osteoporosis

2:27

and marrow edema of the hip,

2:29

but now migrating from one area to another.

2:33

And there were other forms.

2:35

I'm gonna show you some examples of this where only one

2:38

or two digits or a part of the articulation was involved.

2:43

This is an excellent article data taken from this article

2:46

that appeared, that looked at the distribution

2:50

of the initial joint involvement in this condition, RMO,

2:54

and the subsequent joint involvement to see what was

2:58

Typically involved initially.

3:00

Most commonly it was the hip, but then the migration

3:04

or then it might also be a knee or an ankle or a foot.

3:08

Subsequent to the initial involvement,

3:11

you can see typically it migrated to the next nearest joint.

3:15

So the most common location was the knee,

3:18

but you can see others were involved as well.

3:21

And the median time from primary

3:24

to secondary joint involvement was about six months.

3:28

And mo most of the, uh, patients had secondary involvement

3:32

with one year.

3:34

I call your attention that the upper extremity was

3:38

rarely involved or never.

3:40

I think I may have seen one example

3:42

of this in the upper extremity

3:45

and sometimes there was intraarticular migration.

3:49

Okay, and I'll show you what I mean by that.

3:51

So here's an example of intraarticular migration

3:55

of RMO beginning as marrow edema involving the mid portion

3:59

of the lateral femoral condyle.

4:02

And then that went away

4:03

and nine months later, another region

4:05

of the same knee was involved.

4:07

This one with involvement, as you can see of the patella.

4:16

Michelle McCain came along again

4:18

and said, when you look at examples of RMO,

4:20

you may see partial forms.

4:22

And I just wanted to show you what he was noting.

4:25

There was a radial type which could occur where one

4:29

or two digits in the in the foot could be involved.

4:32

And here's an example where the second

4:34

and third digits are being involved.

4:37

And there was a zonal type, okay, where a segment

4:41

of the bone may be involved.

4:43

And here is involvement in the lateral aspect

4:46

of the femoral head,

4:47

but the rest of the femoral head looks normal.

4:50

So the question comes up with trans and osteoporosis

4:55

or osteopenia of the femoral head.

4:57

Yes, there seemed to be an association

5:00

with insufficiency fractures.

5:01

What about this similar entity?

5:04

And if you go in the literature,

5:06

and I did this last about two years ago, it's very hard

5:10

to find any evidence of insufficiency factors

5:14

complicating this condition except in the alis.

5:18

Here's an article that came out in 2005.

5:22

These are images from that article.

5:24

Five cases of regional migratory osteoporosis, one

5:28

of which had imaging findings suggesting

5:32

subcon insufficiency fractures.

5:34

And here are the pictures.

5:35

Perhaps these were insufficiency fractures.

5:39

So there's not a clear cut relationship now, at least

5:42

to this date between regional migratory osteopenia

5:46

and insufficiency fractures.