0:00

A subcon fracture.

0:03

This is defined as a fracture that extends

0:07

through the subc chondral bone

0:09

for a variable distance in a linear

0:12

or curve linear fashion without violation

0:15

or depression of the subcon bone plate.

0:19

So here, perhaps one in a specimen.

0:22

Here's what it might look like, an undulating

0:25

curvilinear type line.

0:27

Here's what it looks like showing you the

0:29

surrounding marrow edema.

0:31

This is a subcon fracture.

0:34

Generally, it indicates an osteochondral injury,

0:39

but in most cases it indicates

0:42

not an osteochondral fracture.

0:45

But you can imagine

0:47

that differentiating a subc chondral fracture from an

0:51

osteochondral fracture can be difficult.

0:54

Ideally, an osteochondral fracture would be curve linear,

0:58

suggesting that the fracture line also involves the

1:02

overlying cartilage,

1:03

whereas subc chondral fracture would be more linear.

1:07

But what do you do with an example like this

1:10

where there is a line

1:11

and the line seems

1:12

to dip down toward the subc chondral bone plate?

1:15

So this may be not a subc chondral fracture,

1:19

but a non-displaced osteochondral fracture.

1:24

In addition, with regard to differential

1:27

of a subc chondral fracture, stress fractures be they

1:30

of the fatigue or insufficiency type,

1:33

and we talked about these in an earlier lecture.

1:36

I show you another example

1:38

of insufficiency fractures involving

1:41

the medial femoral rot tibial compartment on both sides

1:45

associated with meniscal problems.

1:47

This may have been a prior partial, uh, medial menisectomy,

1:53

and I mentioned also in a previous lecture that sometimes

1:57

these subcon stress fractures are not linear,

2:01

but they have little dots.

2:03

And I mentioned and showed you this case.

2:05

This is particularly something I've seen in the subcon bone

2:09

on the acetabular side of the hip.

2:12

Remember this case an ISS film panel case, all

2:16

of the experts got this fracture correctly,

2:20

but when I showed them the mr,

2:21

they realized they might have missed this particular

2:25

fracture on the left.