0:00

Some other findings that we'll see

0:02

with chronic osteomyelitis includes the sequestrum.

0:06

This is a case provided by Dr.

0:08

Patria and shows a beautiful sequestrum

0:12

as this hyperdense structure that is in the middle

0:15

of this humeral shaft,

0:18

and it's surrounded by a, an overwhelming amount

0:21

of new bone formation.

0:23

Um, here on the CT image here and the sagittal

0:27

or reconstructed image in the center of the image on MRI

0:32

that sequestrum, remember it's sequestrated from the rest

0:36

of living bone, meaning its blood supply is gone,

0:41

it has been sequestered away

0:43

and it should not be able to have any, um, communication

0:48

with the rest of the bone.

0:50

So you'll see that the, uh,

0:52

signal intensity is low signal intensity on both T one

0:56

and also T two weighted sequences.

0:59

I find it's actually remarkably hard to see

1:03

on the T two weighted sequences,

1:05

but it's here on the axial images.

1:07

And then on the sagittal image here, it's this focus

1:11

of low signal intensity with surrounding more marrow edema.

1:17

So the importance of this is that

1:19

because it's sequestered away from the vascular supply,

1:23

the IV antibiotics that the clinicians may be trying

1:27

to give this patient are not going to be able

1:29

to reach this sequestrum,

1:30

and thus it will continue to be ais for infection

1:35

if it's not removed.

1:37

Here's, uh, another case showing more bony, uh, involvement

1:42

around the, uh, sequestrum in the center.

1:46

And so this outside bone can be referred to as the Ingram,

1:50

which is kind of more living bone

1:53

that has still some reactivity to it, whereas remember

1:56

that sequestrum has no, uh, vascularity to it.

2:01

One more case this time in a child showing that

2:05

hyperdense sequestrum within the center of the ulna with the

2:10

bone formation or the involucrin forming

2:13

and expanding the ulna, uh,

2:15

seen nicely on the S scout Topo Graham,

2:17

and also the, uh, reformatted images here.

2:22

So just for a guide to, uh, chronic osteomyelitis, I

2:27

provided this table just in case you forget, uh, which, um,

2:31

which, uh, hyperintensity

2:34

or hypo intensity it should be for the sequestrum,

2:38

the lucrum granulation tissue and draining sinus tract

2:42

and soft tissue infection, or sorry, inflammation.