0:00

We're gonna move on now

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and we're gonna talk about stress injuries.

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And let me again introduce the nomenclature

0:08

that I mentioned a while back.

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The nomenclature stress fracture, a general term

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for a fracture that relates to repetitive normal

0:17

or abnormal force placed upon normal or weakened bone.

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That's the general derm.

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Two types, a fatigue fracture shown here, a fracture

0:28

that relates to repetitive abnormal force

0:31

placed on normal bone

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and an insufficiency fracture shown by these two pictures.

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A fracture that relates to repetitive normal

0:40

or abnormal force placed upon bone weakened

0:44

by a number of processes.

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We're gonna talk about some of these stress fractures.

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Some are gonna be fatigue, some are gonna be insufficiency.

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Well, let's look at their classic locations

0:57

early on in residency.

0:58

Most of us learn about the classic position

1:01

of the calcaneal stress fracture vertical

1:04

or vertical O like involving the posterior aspect

1:08

of the calcaneus.

1:09

So we can see things like this classic appearance

1:13

of a stress fracture of the calcaneus.

1:16

What I want to do with this particular slide

1:19

and the lower example

1:20

to emphasize another place in which you may see these stress

1:25

fractures, and that is beneath the two sub joints,

1:29

in my experience,

1:30

more often the posterior sub Taylor joint than the talo

1:35

calcan navicular joint.

1:37

And here's an example of what that might look like.

1:41

Another phenomenon that we see in the calcaneus

1:44

that I'll just mention briefly is probably related to stress

1:48

and occurs of course in the very young, in children

1:53

and adolescents.

1:54

And it relates to something called sever phenomenon.

1:59

I call it a phenomenon because it is reversible.

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We may see it radiographically as sclerosis

2:05

of the developing hypothesis of the calcaneus.

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And when we study it with MR as in this particular example,

2:13

we may see altered signal intensity in the images,

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but the pain that goes with this

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and the imaging abnormalities

2:21

that accompany it generally go away over a period of time.

2:25

So I think of this more as a phenomenon than a significant

2:30

traumatic abnormality.

2:33

Let's move now and talk about stress fractures involving

2:37

the uh, tailless.

2:38

And here in fact there are classic locations

2:41

and these can be fatigue or insufficiency fractures.

2:45

The ears in one example,

2:47

and you can see it nicely in this upper images as well

2:51

as on the opposite ankle region in this single patient,

2:56

this is just above the posterior sub

2:58

Taylor joint. And

2:59

as I remember,

3:01

this was a fatigue fracture in this person.

3:04

On the bottom you can see an example

3:07

of subcon flattening.

3:10

Uh, here the bone plate is flattened.

3:12

That is a fracture

3:14

and insufficiency fracture with marrow edema.

3:18

This fracture involving the distal portion of the alis.

3:23

Now I just wanna remind you,

3:25

and something I didn't include in the earlier lecture when I

3:28

talked about transient bone marrow edema

3:31

that we have reported seeing this in the alis.

3:35

I'm showing you the article that

3:37

that was written from UCSD years ago now,

3:41

but we have seen examples with patchy

3:43

or widespread tailor edema, hot on bone scan,

3:48

and we followed some of these persons

3:49

and they never developed, uh, stress

3:53

or uh, stress fractures, be it a fatigue or insufficiency.

3:58

So is this regional migratory osteoporosis

4:01

with transient bone marrow edema?

4:04

I am not certain. I want

4:07

to illustrate another case showing you a significant

4:10

abnormality that you may see.

4:12

This is a young athletic man

4:14

with increasing medial ankle pain during running.

4:19

I'll let you look at that a moment

4:21

and you can see the abnormalities.

4:23

So this is a stress injuries

4:25

involving the subc chondral bone of the medial Taylor dome.

4:30

You can see that outlined by one of the black arrows.

4:33

And then another one, a small stress fracture here shown

4:38

by the white arrow occurring at the junction

4:41

of the tibial pathon and the medial malis.

4:45

This is a location that is not well known to many people,

4:49

and yet it is one in which these fractures,

4:52

these stress injuries may occur.

4:54

It was emphasized in an article a number of years ago by one

4:58

of our former, uh, fellow Jean Shields from Cleveland.

5:03

And indeed, the reason you wanna pick these up is in some

5:06

cases, if they are not picked up

5:08

and treated in some fashion, usually conservative treatment,

5:12

you may end up with a complete fracture

5:15

as in this particular case.

5:19

There's an example bilateral showing you multiple stress

5:24

fractures involving multiple bones here, the tibia,

5:27

calcaneus, and navicular.

5:30

It's not unusual in some of these cases

5:33

to see bilateral involvement

5:35

and multiple sites of involvement.