0:01

The signal intensity changes in the endplates

0:05

within the lumbar spine,

0:07

thoracic spine, or for that matter,

0:09

cervical spine were initially described by Michael Modic

0:14

who is a neuroradiologist out of Ohio.

0:17

And these are sometimes affectionately called

0:20

modic changes for Michael Modic.

0:24

I'll describe the various types

0:26

and the significance thereof.

0:28

The first is the Type I change.

0:31

The Type I change can be seen on these scans.

0:35

We have a T1-weighted scan to the left,

0:37

T1-post gad in the center

0:40

and T2-weighted scan on the right.

0:43

The modic changes really were about the

0:46

T1 and T2 imaging characteristics.

0:50

With Type I change,

0:53

we have dark signal intensity in the endplates

0:57

around a disc on the T one weighted scan

1:02

and these correspond to brighter signal

1:05

intensity on the T2-weighted scan.

1:08

So dark on T1, bright on T2.

1:12

This would be Modic Type I change

1:14

or Type I endplate changes.

1:18

There may or may not be evidence of contrast

1:21

enhancement on the post-gadolinium enhanced

1:25

scan, which you see in the middle.

1:27

That was not the main emphasis here.

1:30

This is from an article that was published

1:33

in 2008 in which there was

1:38

a description of the modic changes,

1:42

the Type I changes that corresponded

1:45

to inflammation of the endplates.

1:47

So when we think of dark on

1:49

T1 and bright on T2,

1:50

it sort of suggests that there's increased

1:52

water content or edema of the endplate.

1:56

And this was thought to represent some element of

2:01

segmental instability causing

2:03

irritation of the endplates.

2:05

So you see that it was strongly associated

2:09

with low back symptoms.

2:11

So although many of us kind of dismiss it,

2:14

dismiss modic changes as merely

2:16

a degenerative phenomenon,

2:18

when they look at patients who are

2:20

symptomatic with back pain,

2:22

they do seem to have higher rate

2:24

of Type I endplate changes.

2:27

That being dark on T1 and bright on T2.

2:30

It's generally agreed that the Type I Modic change

2:35

changes over time to either Type II change,

2:40

which is going to be bright on

2:42

T1 and bright on T2,

2:44

or it will revert back to the normal bone

2:47

marrow signal within six months.

2:49

So this is something that is a dynamic change that

2:53

one finds in the endplates. Type II change,

2:57

by contrast, if you go from Type I to Type II,

3:01

those are usually stable over the course of time,

3:04

be it months to years.

3:06

The Type II change, as I stated,

3:09

is bright on T1 and bright on T2.

3:13

And this is usually when we're talking

3:15

about fast spin echo T2.

3:17

And therefore, most people think of the Type II

3:19

change as some element of fat that

3:22

is accumulating in the endplate.

3:24

So when you have something that is bright

3:26

on T1 and bright on T2,

3:28

we would call it Modic Type II change.

3:32

This is our T1-weighted scan and you see that

3:35

there is high signal intensity in the endplate,

3:37

high signal intensity in the endplate.

3:39

And when you check that with the T2-weighted scan

3:43

and compare that signal intensity

3:45

to the normal bone marrow signal,

3:47

you notice that that is bright as well.

3:49

Same thing over here.

3:50

It's a little brighter than the

3:51

corresponding bone marrow.

3:53

So this would be Modic Type II or Type II endplate changes.

3:57

And as I said,

3:58

this usually evolves from a Type I change.

4:03

Type III change refers to low signal intensity

4:07

on T1-weighted scan and low signal intensity

4:10

on T2-weighted scan.

4:12

Therefore, we tend to think of this as a demonstration

4:15

of what happens on CT as Sclerosis,

4:18

that is the brighter density on

4:21

CT from Type III change.

4:24

This is the T1-weighted scan on the left

4:28

and T2-weighted scan on the right.

4:30

So our T1-weighted scan,

4:32

we see that we have dark signal intensity in the

4:35

endplates around this, probably L2-L3 disc level.

4:41

And as opposed to Type I change,

4:44

we see that this is dark as well on the T2-weighted scan.

4:49

So Type III changes, dark on T1,

4:55

dark on T2.

4:57

That's to be distinguished from Type I change,

5:00

which is dark on T1 but bright on T2.

5:06

Now, this all seemed relatively mundane and not all

5:11

that important or exciting until several

5:16

publications in 2016, 2017, 2018,

5:22

looked at doing biopsies of these endplates.

5:28

And what they found was a preponderance of

5:31

cultures of propionibacterium acnes

5:36

within Modic Type I changes.

5:40

So here we have, from the Journal of Orthopedic Research

5:44

and from the European Journal of Spine,

5:47

that Modic changes were associated with

5:54

growth of propionibacterium acnes in culture.

6:00

And that this may represent a low grade,

6:05

if you will, inflammation or infection even.

6:09

So, the next group took this one step further.

6:13

How about if we institute antibiotic therapy to

6:18

treat the propionibacterium acnes and see

6:24

what happens with the patient's pain.

6:26

And what you find is that in this double

6:29

blind randomized control trial,

6:32

that in point effect, antibiotic treatment resulted

6:36

in greater relief of low back pain in those that

6:41

received the antibiotic than those receiving placebo.

6:46

So, this has led to some people claiming that Modic

6:50

changes, if you will, Type I changes,

6:52

actually reflect a low grade infection,

6:56

not just degenerative change.

6:59

This was the conclusion from that.

7:01

Again, when you talk about level of evidence in medicine,

7:05

you can't get much better than a double blinded

7:08

randomized placebo control trial.

7:11

And this was the conclusion.

7:12

The antibiotic protocol in this study was

7:14

significantly more effective for this group in

7:16

chronic low back pain than placebo in all

7:19

the primary and secondary outcomes,

7:21

those being, you know,

7:22

back pain and taking of pain medications.

7:26

And so, a review article in 2015 on this also said

7:30

that bacteria are common in the discs,

7:33

as well as in the endplates,

7:35

and they may be associated with both low back

7:38

pain, as well as Modic Type I change.

7:41

And if you read the last sentence,

7:43

"However, further work is needed to determine whether these

7:45

organisms are result of contamination or represent

7:48

low grade infection of the spine,

7:50

which contributes to chronic low back pain."

7:53

Suffice it to say that there are some clinicians

7:55

out there that are putting patients with low back

7:58

pain and change from normal Modic change to

8:03

Modic Type I change on antibiotics.

8:08

Fascinating.

8:09

And here is a paper that was published

8:12

in our Journal of Neuroradiology,

8:15

the American Journal of Neuroradiology, in 2018.

8:19

Looking again in the cervical spine,

8:21

not the lumbar spine.

8:22

Now we're in the cervical spine with Type I

8:24

Modic changes and propionibacterium acnes.

8:27

And I'll just read the conclusion.

8:29

"We conclude that P. acnes was prevalent in

8:31

degenerative cervical spine. Type I Modic changes

8:34

were predictive of culture positive

8:36

propionibacterium acnes and that this is not

8:40

associated with interventions such

8:42

as lumbar punctures or previous

8:46

pain relief procedures such as facet block, et cetera.

8:50

And that this may be something that we should be

8:53

paying a greater amount of attention to with

8:56

regard to back pain and neck pain.