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learn alongside top radiologists from around the world.

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by creating a free MRI online account.

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Today we are honored to welcome Dr.

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Donald Resnick for a lectured entitled Osteomyelitis,

0:30

septic Arthritis and Soft Tissue Infection Mechanisms,

0:33

imaging Findings and Complications.

0:36

Dr. Resnick is a renowned lecturer and his list of awards

0:38

and honors include twice awarded AMP mini dot com's,

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most effective radiology educator 20 eighteens a CR gold

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medal for his lifetime achievements

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and an honorary doctorate from the University of Zurich.

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We're so thrilled he's here today

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to share his expertise with all of us.

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At the end of the lecture, please join him in a q

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and a session where he will address questions you may

0:59

have on today's topic.

1:00

Please remember to use the q

1:02

and a feature to submit your questions so we can get to

1:04

as many as we can before our time is up.

1:07

With that, we are ready to begin today's lecture. Dr.

1:10

Resnick, please take it from here.

1:13

Thank you very much. It's a privilege, uh, to be able

1:15

to uh, talk to you this morning on a subject

1:19

that I think is important

1:20

and that is osteomyelitis, septic arthritis

1:23

and soft tissue infection.

1:26

What we plan to do over the next 50 minutes is discuss basic

1:30

mechanisms of these infections, some

1:33

of their imaging findings,

1:35

both using conventional techniques

1:38

and some of the more advanced imaging techniques.

1:41

And then at the end in a short segment, a couple

1:44

of complications that may occur.

1:47

I have one general objective to review the mechanisms,

1:51

imaging findings

1:52

and complications of musculoskeletal infection.

1:56

The lecture is divided into four parts

1:59

that I've listed there.

2:00

We'll start with acute osteomyelitis, turn our attention

2:04

to septic arthritis and then deal with subacute

2:08

and chronic osteomyelitis finishing with complications.

2:12

Now I'm very careful in the terminology

2:15

that I'll use throughout this lecture, so let me introduce

2:18

that terminology to you right now.

2:22

If we have infection of the periosteal membrane,

2:26

I'll use the term infective peros.

2:29

If we have infection of the cortex,

2:32

you'll hear the term infective osteitis.

2:36

If we're dealing with infection of marrow,

2:38

I will utilize the term osteomyelitis

2:41

and of a joint infection will be called septic arthritis.

2:45

I'll also refer to soft tissue infections throughout this

2:48

lecture, but I won't designate what type

2:50

of soft tissue infection.

2:52

I'll save that for another lecture, uh, at another time.

2:57

Now let me give you an overview right at the beginning

3:00

that'll kind of simplify what is to follow.

3:03

There are two basic ways in which bones become infected.

3:08

The first of these, I'm gonna call the

3:10

inside out mechanism of infection.

3:13

Here, for example, with hematogenous osteomyelitis, we deal

3:18

with an infection that begins within the medullary cavity

3:21

and if not treated promptly

3:23

or correctly extends out into the soft tissues.

3:27

These sequential steps would be osteomyelitis, infective,

3:32

osteo infective, peros, titis,

3:35

and then soft tissue infection.

3:38

More common in my practice

3:40

and I imagine in yours as well, is the second basic pattern

3:44

that we see and that is an outside in

3:47

the most common example is the soft tissue infection

3:50

that eventually invades the bone.

3:53

Here are the steps are the opposite.

3:56

We begin with soft tissue infection, then infective, peros,

4:00

titis, infective, osteo, and finally osteomyelitis.

4:06

So let's begin with part one, acute osteomyelitis

4:09

and I indicate with this particular table taken from the

4:13

literature some of the microorganisms

4:16

that may be involved in causing osteomyelitis.

4:19

You can see and the arrow points out

4:22

that in the vast majority of cases we're dealing

4:25

with staphylococcal infection, particularly that related

4:28

to porus.

4:29

Now there are some other situations listed on this

4:32

particular slide that indicate modifications

4:36

of this typical microorganisms.

4:39

For example, in sickle cell disease,

4:41

although we certainly can have staphylococcal infection,

4:45

we may also deal

4:46

with other organisms including salmon manila.

4:49

As listed here, there are four basic roots

4:53

of contamination that lead to osteomyelitis.

4:57

We'll begin by talking about the hematogenous root.

5:01

To understand that, please be aware

5:03

that in the tubular bones there are nutrient vessels

5:06

that enter the medullary cavity at one or two places

5:11

and extend toward the end of the bone by a smaller

5:14

and smaller vessels.

5:17

I outline that

5:18

with the yellow arrows in this particular drawing,

5:22

somewhere at the end

5:23

of the bone we have capillary ramifications

5:26

and I'll talk more about where this occurs in a moment.

5:29

Here, the vessels make sharp turns.

5:32

Typically the blood flow is sluggish in this region shown

5:35

by the white arrow, and this is the ideal setting

5:39

for hematogenous osteomyelitis

5:42

and then the vessels as veins

5:45

retrace the arterial roots shown by the blue arrows here

5:49

exiting through those nutrient channels.

5:53

Now other vessels shown

5:54

by the green arrows will enter the epiphysis

5:57

or metaphysis directly,

5:59

but they are statistically less important as pathways

6:03

for hematogenous osteomyelitis.

6:08

Now to understand exactly what we see with imaging studies,

6:11

you must recognize there are three basic

6:14

vascular patterns that we see.

6:16

The first I'll call the vascular pattern in the child,

6:20

typically between the ages of one and maybe 16 years.

6:24

Here, the vessels tend to end in the region

6:27

of the metaphysis

6:28

where capillaries form blood flow is sluggish

6:32

as shown on this particular drawing.

6:35

The second vascular pattern is that of the infant here,

6:39

some vessels extend around or occasionally through the FSIS

6:43

or growth plate into the epiphysis shown in

6:47

this particular drawing.

6:49

And then the third pattern,

6:50

after the age of about 16 years when the FSIS is closing

6:54

or is completely closed, there is vascular continuity

6:58

between the diaphysis, the metaphysis, and the epiphysis.

7:03

So those are the three basic vascular patterns

7:07

that we see based on age

7:09

and they explain a lot of what we see

7:11

with osteomyelitis when we view a variety

7:14

of imaging techniques.

7:17

Typically, when we deal

7:18

with acute osteomyelitis in the child, we are dealing

7:22

with meta fassil localization of infection.

7:26

I can recall many years ago I learned that

7:28

during my first year of residency to look

7:32

for meta fassil osteomyelitis.

7:35

It's a great rule, but as I'll show you,

7:37

there are exceptions here.

7:39

Taken from the literature on the right,

7:41

you can see histologic evidence of foci

7:44

of bacteria in a setting of hematogenous osteomyelitis.

7:51

What occurs in this age group is osteomyelitis typically

7:54

begins within the medullary cavity.

7:57

Then if not treated correctly

7:59

or promptly, it will contaminate the cortex.

8:02

Infective osteo lift the perio osteo membrane,

8:07

subsequently contaminated infective peros titis,

8:11

and then through the process

8:13

of intramembranous bone formation,

8:15

periosteal new bone is visualized.

8:18

The example on the right shown

8:20

by the arrows indicates metaphyseal osteomyelitis

8:24

with associated infective osteous, infective titis

8:29

and periosteal P bone.

8:31

This is what I learned as a first year resident,

8:33

but back then we didn't have MR imaging.

8:36

When Mr Imaging came along, we saw, we saw, in fact,

8:39

there were many exceptions to the rule here.

8:42

A case taken from the literature from a while ago shows you

8:47

metaphyseal infection that has spread through the crisis

8:51

reaching the epiphysis.

8:53

So although the rule, the vascular rule is helpful,

8:56

it is not without exceptions, something to remember.

9:01

Now, I learned about exceptions when I was a resident

9:03

because with granulomas infections such as here tuberculosis

9:08

spread through the fsis into the epiphysis was something

9:11

that we expected here on your right.

9:14

An example, an old example of tuberculous osteomyelitis.

9:18

You'll note also the consolidation in the upper lobe

9:22

of the lung.

9:23

So trans physio spread

9:25

with granulomas infection is something we expect.

9:29

Rarely we see involvement that begins in the epiphysis.

9:34

A nice case sent to me years ago from one

9:36

of our previous fellows show you epiphyseal contamination

9:41

hematogenous in origin

9:44

involving here the distal femoral epiphysis shown

9:48

beautifully by the arrows in these images.

9:53

Let's turn our attention now to acute osteomyelitis.

9:56

In the infant here, owing to the vascular extension

10:00

to the epiphysis hematogenous infection may begin in the

10:04

epiphysis and with that a couple of complications may occur.

10:09

Higher frequency of septic arthritis may be seen.

10:13

We'll be talking in detail about septic arthritis in a

10:16

little while and once the epi side

10:20

of the growth plate is involved,

10:23

growth disturbances can be seen.

10:27

I show you an old case,

10:28

but it's a beautiful one of Hematogenous

10:31

osteomyelitis in a very young child, an infant

10:35

involving the metaphysis seen in the upper image

10:38

with conventional radiography

10:40

and then with one of the early MR images,

10:43

you can see contamination of the epiphysis

10:46

and a septic arthritis.

10:48

Something we expect to see in the infant

10:53

when we deal with acute osteomyelitis in the adult,

10:57

although often it is the axial skeleton that's involved

11:00

when a tubular bones are involved shown here,

11:05

epi aile localization may occur.

11:08

Hence there is some risk,

11:10

although it's a low risk of septic arthritis.

11:13

In addition, because the periosteal membrane is firmly

11:16

adherent to the cortex in the mature skelet, the degree

11:20

of periostin

11:22

and subperiosteal abscesses tends

11:25

to be less in adults than in the immature skeleton

11:29

of children or infants.

11:32

An old example, but a nice one

11:35

showing you hematogenous osteomyelitis

11:38

involving the epiphysis

11:40

and metaphysis of the femur spreading into the joint,

11:44

producing now a septic arthritis

11:47

T one image on the upper image

11:50

and then the gadolinium image shown at the bottom.

11:55

The second basic mechanism

11:57

and the one that I see more frequently in my practice is

12:00

spread from a contiguous contaminated source.

12:04

Typically it's a soft tissue infection

12:06

that extends into the bone.

12:09

The first is violation of the periosteal membrane,

12:13

infective peros with intra ous bone formation

12:18

and periosteum bone observed with imaging studies.

12:22

Subsequently, there's contamination

12:24

of the cortex infective osteo,

12:27

and then over time, as you might expect,

12:29

osteomyelitis may develop.

12:32

Now there are certain regions in the human body

12:35

where this particular mechanism is operational.

12:40

Let's deal first with the hand.

12:42

This is a drawing I made some years ago showing you the

12:45

palmar aspect of the hand

12:47

and wrist, also including the fingers.

12:51

I'm gonna add layer by layer some

12:53

of the important structures that allow infections

12:56

in the soft tissues to spread into bone.

13:00

The first thing I'm gonna add are some soft tissue spaces

13:04

that may become infected on thenar side.

13:08

We call this the thenar space.

13:10

On the uh, palmar side, we call this the mid polymer space.

13:16

I'm now gonna add the flexor tendon sheets of the second,

13:19

third, and fourth fingers.

13:21

Now there are variations in these patterns,

13:24

but in most of us, most of you listening,

13:27

this is the anatomic arrangement that is present.

13:30

There are flexor tendon sheaths and the second, third

13:33

and four fingers that stop just proximal

13:36

to the metacarpal head to this diagram.

13:39

Now I'll add the flexor tendon sheath about the lysis

13:43

longest tendon

13:45

and in most of us it contends continues into the palm

13:50

and forms a a more extensive area we call the radial bursa.

13:55

I'm also gonna add now the flexor tendon sheet

13:59

that we see in the fifth finger

14:02

and you can see it extends into the palm

14:05

and most of us as in ulnar bursa.

14:08

So in the carpal tunnel

14:10

and around the carpal tunnel there are radial

14:14

and ulnar bursa and they may communicate

14:18

although not shown here by intermediate bursa.

14:21

Now let's finish this up.

14:22

We add the transverse carpal ligament covering the carpal

14:27

canal or carpal tunnel

14:28

and I'll add one more space, the space of corona located

14:32

beneath the distal radius.

14:34

I won't be talking about Corona space infections today,

14:38

but they are very, very important.

14:42

If we have an infective flexor teno synovitis,

14:46

typically in the second, third

14:47

and fourth finger, we would expect a teno synovial fluid

14:52

to end just proximal to the metacarpal head.

14:55

I show you the anatomy and sagittal section of such a finger

14:59

and on an Mr image, this would be consistent

15:02

with infective teno synovitis

15:05

and if this infection is not treated promptly, we may deal

15:09

with osteomyelitis,

15:14

septic arthritis or spread

15:16

of the tendon sheet infection into the mid palmer

15:19

or thenar space.

15:22

Now there are other patterns that we see for infective.

15:25

Uh, for example, infective nar and radial bursitis.

15:31

As you can see here, this creates something the shape

15:34

of a horseshoe and this is called a horseshoe abscess.

15:38

I show you an example

15:39

of infection involving the flexor tendon sheets of the thumb

15:43

and of the fifth finger extending into the palm

15:46

contaminating the radial

15:48

and nar bur se this would be a horseshoe abscess.

15:53

Here's another case sent to me

15:56

and you can see a beautiful example

15:57

of a horseshoe abscess clinically as well

16:01

as utilizing MR imaging.

16:03

Note the shape, the contamination of the thumb

16:06

and fifth finger and of the burse that are located within

16:11

the volar aspect of the wrist.

16:14

In other examples, it's only the ulnar bursa

16:17

that is contaminated.

16:19

This particular pattern of infection produces a shape

16:23

that looks like an hourglass.

16:25

I show you an example here utilizing MR imaging

16:29

fluid sensitive at the top,

16:31

gadolinium enhanced at the bottom

16:33

to show you a beautiful example of infective nar bursitis

16:38

and the horse, the hourglass shape owing to the fact

16:42

that the infection in the carpal tunnel is more restricted

16:46

in space, hence the appearance of an hourglass.

16:51

This can occur with bacterial infections,

16:53

it can certainly occur with tuberculosis.

16:56

Here's a beautiful example

16:57

of infective ulnar bursitis occurring

17:01

in Osis.

17:05

The second place at which this particular mechanism may

17:08

occur of course, is in the foot,

17:10

and here we deal often with the diabetic foot infection.

17:15

The clue to accurate diagnosis as shown here

17:18

with uh two radiographs taking uh, weeks apart is

17:22

that we look for an area of soft tissue ulceration

17:27

because in the vast majority of cases

17:29

of osteomyelitis involving the diabetic foot,

17:33

there is a nearby soft tissue ulceration.

17:36

In the case I'm showing you, it began as you can see

17:39

with an ulcer involving the heel

17:42

and then weeks later extensive osteomyelitis

17:46

of the calcaneus.

17:48

Now for those of you who deal with diabetic feet

17:51

and are trying to figure out what's going on, you recognize

17:55

that we have a real diagnostic problem in the

17:58

differentiation of osteomy from changes that occur

18:02

with neuropathic disease

18:04

and then some cases it's very, very difficult

18:07

to tell the two apart,

18:09

but one of the findings that has been

18:11

emphasized in the literature is the presence

18:14

or absence of a ghost sign.

18:17

Now the ghost sign is said to indicate loss

18:20

of the cortical outline

18:21

of the bones on T one weighted images.

18:24

Now I would add that it's also loss of the subcon bone plate

18:28

of these bones, not just the cortex of the bones.

18:32

If you see loss of those cortical

18:35

and subcon bone plate outlines,

18:39

a positive ghost sign is more indicative of osteomyelitis

18:44

or at least shows you in part that the findings relate

18:48

to osteomyelitis.

18:49

The example I show you in the middle,

18:51

taken from the literature

18:53

and emphasizes

18:54

that ghost sign in the bottom T one weighted image, compare

18:59

that for example to the one on the right

19:03

neuropathic disease without osteomyelitis

19:06

and you'll see an absent go sign the cortex

19:09

and subcon bone plates of these bones

19:12

can be visualized at least in part on the T one

19:16

weighted Mr image.

19:18

So this is an important sign.

19:19

It doesn't always work, but it's something that I look for.

19:24

The third site, which spread from a continuous contaminated

19:28

source may be seen is in the naic bones.

19:32

That's a fancy name for the mandible and maxilla.

19:35

Here you can see a beautiful example of a specimen,

19:39

a specimen radiograph showing you infection

19:42

involving the root or apex of the tooth.

19:46

Note, the lucency in the middle of the circles was spread

19:50

to the mandible.

19:51

Now, a little bit later I'll talk about the appearance

19:54

of sclerosis in this particular

19:57

situation shown nicely in this example

20:00

often called rosing osteomyelitis of guray.

20:04

It's a poor name as I will explain later.

20:07

Now, you will occasionally see the same mechanism at other

20:11

sites and the other site

20:13

that I would emphasize is shown in this case,

20:15

which awaited me during my first month when I arrived

20:19

as a faculty member at the VA medical Center in San Diego.

20:23

This was a veteran who had had a hair transplantation,

20:27

so let me add the hair transplantation

20:30

and that transplantation became infected

20:33

and indeed infected the cranial vault, as you can see here,

20:37

spread from a contiguous contaminated source.

20:42

Unfortunately, for this veteran, a large part

20:45

of the cranial vault had to be removed.

20:47

It's a rare complication of hair transplantation,

20:51

but seeing it, I put off my own surgery now

20:54

for a number of years.

20:56

Another situation in which we may have spread from a

21:00

contiguous contaminated source relates to septic bursitis.

21:05

This can involve any of the bursa,

21:08

particularly superficial bur se about the human body,

21:11

but it is most common in the pre patella

21:14

and as shown here in the all non bursa, it can relate

21:19

to bacterial, fungal or tuberculous infection.

21:23

In fact, whenever I see a infective bursitis,

21:26

I always wonder could it be tuberculosis?

21:30

I show you a beautiful example with conventional radiography

21:34

and various sequences on R

21:36

of a septic Quin on bursitis with contamination

21:41

of the sub bone

21:43

and you can see the altered marrow signal within theum.

21:48

There's one fungal disease that I would emphasize

21:51

that often leads to osteomyelitis related

21:54

to soft tissue infection

21:57

and that fungal disease is por truss here.

22:00

Images taken from a recent article in Radiographics showing

22:04

you the clinical picture

22:06

and the imaging findings associated

22:09

with this particular fungal infection.

22:12

This is often seen in gardeners and farmers

22:15

and nursery workers related to cuts

22:18

and scratches that introduce the organism.

22:21

Rose thorns are often the source of the infection,

22:25

as you might expect

22:26

that typically we see this in the distal portion

22:28

of the extremities, the hands, the fingers,

22:31

the feet and the toes.

22:33

This is something to consider when you see infection,

22:36

particularly in a gardener or nursery worker.

22:42

The third mechanism leading

22:43

to osteomyelitis is direct implantation of infection.

22:48

I show you that diagrammatically on your left,

22:51

the same mechanism of course could produce

22:53

a septic arthritis.

22:55

This brings us to the subject of bite injuries.

23:00

We can deal with human bites, we can deal with animal bites.

23:04

I can show you here some organisms related to human bites,

23:08

dog bites and cat bites.

23:10

You'll see with dog bites

23:11

and cat bites, Ella is often the microorganism

23:15

that is involved, whereas when dealing with human bites,

23:18

that strep or staphylococcal

23:21

microorganisms that are involved.

23:23

Now I can tell you that if you had your choice

23:27

of being bitten by a human, by a dog

23:31

or by a cat, some would suggest stay away from the human

23:34

because the human bite can lead

23:37

to significant complications.

23:39

But of course there are various types of dogs

23:41

and certainly various types of cats that might produce major

23:46

uh problems.

23:48

But human bites can be a problem

23:51

of interest when you compare what occurs related

23:54

to musculoskeletal infections with cat versus dog bites.

23:59

Some would suggest that cat bites are more serious

24:03

and more likely to cause osteomyelitis.

24:06

They have sharp teeth, they pierce tissues,

24:09

they produce little soft tissue damage,

24:12

and so the bacteria is often localized

24:15

to the deeper soft tissues

24:17

and the bump dog bites in comparison,

24:22

stronger blunt teeth lead to crushing injuries, fractures

24:25

and things of that sort.

24:27

Taken from the literature here, an example

24:30

of osteomyelitis related to a CAC bite

24:34

of a finger.

24:36

This brings us to the human bite

24:38

and of course the example that we think

24:40

of is the fist fight here.

24:43

This occurs when the opponent strikes the mouth, all right,

24:47

leading to considerable damage that may include a mandibular

24:51

fracture and loss of teeth long

24:54

after the supposed losers mandibular fracture has healed.

24:59

The winner may have a septic arthritis

25:03

of particularly a metacarpal phenal joint

25:06

because the tooth entered that joint at the time

25:09

of the blow to the mouth.

25:11

Now sometimes the diagnosis is made easy as in this example

25:15

because there is dental material present that allows you

25:19

to suggest that any abnormality of the

25:22

metacarpophalangeal joint may relate to a

25:26

septic arthritis

25:29

and then postoperative infection producing osteomyelitis

25:33

and there are here it can relate to fractures,

25:37

spine surgery, joint replacement, sternotomy.

25:40

I'll leave that discussion to another day.

25:44

We're gonna move on now to part two

25:46

and that is septic arthritis

25:49

and here we deal with infections of joints.

25:52

This particular picture taken from the literature

25:57

emphasizes the various microorganisms emphasizing again,

26:02

that is typical staphylococcal infection that dominates

26:07

with causes of septic arthritis.

26:11

Any of those four mechanisms we've already talked about can

26:15

lead to septic arthritis,

26:18

but the situation is a little bit more complicated than

26:21

with osteomyelitis.

26:23

Let me explain. As we go through these various mechanisms

26:27

when dealing with hematogenous septic arthritis,

26:30

there are two particular ways in which the joint

26:34

may become infected.

26:36

I illustrate that by these screen and orange circles.

26:41

The first of these would be direct transport

26:44

of the microorganisms to the synovial membrane shown

26:48

by the orange um dot.

26:50

In this particular uh, uh, picture

26:54

or drawing that I made, the second would be spread

26:59

from an epiphysis when there is direct vascular continuity

27:03

between the epiphysis

27:05

and the synovial membrane shown

27:07

by the green circle in my drawing.

27:10

In both of these situations, the synovium tends

27:15

to be contaminated before the joint fluid.

27:17

Now that has some importance If you aspirate the joint,

27:21

it may be initially negative if you do a synovial biopsy,

27:25

you may in fact confirm that you're dealing

27:28

with a septic arthritis.

27:30

I show you an example taken from an exhibit at the RSS NA

27:34

about seven or eight years ago,

27:37

hematogenous septic arthritis involving the left hip shown

27:41

with a T one weighted fat suppressed IV

27:44

gadolinium enhanced image.

27:46

You can see the synovitis is high signal the fluid

27:51

infected fluid in the joint as low signal

27:53

and you can see the low signal of the non ossified epiphysis

27:58

of the left femoral head indicating osteonecrosis

28:03

as the infection in the joint led

28:05

to a large joint effusion which interrupted the blood supply

28:09

to the epiphysis septic

28:12

or arthritis hematogenous in origin.

28:15

Once the infection contaminates the synovial membrane,

28:19

the classic early erosions of bone occur at the margins

28:23

of the joint, often called the bear areas.

28:26

Hopefully you know that particular finding.

28:28

Well it can be seen nicely with conventional radiography

28:32

or more advanced imaging methods.

28:37

The second mechanism is spread from a

28:39

contiguous contaminated source.

28:41

Let's deal with the bone

28:43

and once again it's a little bit more complicated than when

28:46

we talked about hematogenous osteomyelitis.

28:50

There are two ways in which this may occur.

28:53

Shown here by the orange arrow,

28:56

an infection involving the epiphysis may destroy the subcon

29:00

bone plate extend into the cartilage

29:02

and then into the joint

29:05

spread into the joint from a nearby contaminated source.

29:09

The second way this may occur shown

29:13

by the green hour occurs in certain anatomic sites

29:17

where the metathesis is intracapsular.

29:20

And although, although there are several such sites, the one

29:23

that I would emphasize shown nicely

29:26

in this particular example taken from my book years ago is

29:31

the hip here, the metathesis of the proximal portion

29:36

of the femur is intracapsular

29:38

and infection may spread from here into the joint.

29:43

All right? And that's exactly what occurred here,

29:46

shown nicely over a period of time

29:48

as a septic arthritis leading to osteomyelitis

29:52

and osteonecrosis of the femoral epiphysis.

29:58

The same mechanism producing septic arthritis can relate

30:03

to soft tissue infection.

30:05

Here again, the diabetic foot comes to mind.

30:08

This is an example indicating the importance

30:11

of finding the soft tissue ulceration,

30:14

which in this case contaminated the great toe metatarsal

30:17

falange joint involving both the OIDs

30:22

and the metatarsal head septic arthritis related

30:26

to spread from a contiguous contaminated source

30:30

and direct implantation.

30:32

And again, I return to the human bite here,

30:35

the typical example involving a metacarpal falange joint

30:40

following a fist fight.

30:42

Note the joint space narrowing the open arrow shows

30:45

that note the marginal erosion along the radial aspect

30:49

of the metacarpal head

30:51

and in a different case, a Mr. Case showing you involvement

30:55

of that joint following a fist fight, direct implantation.

31:01

And then finally, postoperative mechanism leading

31:04

to septic arthritis.

31:06

The example I show you here was a patient

31:09

who had a femoral fracture treated

31:11

with intramedullary rotting which became infected.

31:14

The rod was removed

31:16

and you can see osteomyelitis with septic arthritis

31:20

involving the knee.

31:25

Now our general rule of course for septic arthritis

31:28

with very few exceptions is we're dealing

31:31

with a single joint monoarticular involvement.

31:35

But I wanna emphasize there are exceptions to that rule.

31:39

And the first of these is a pre-existing joint disorder,

31:43

and the one I would emphasize the most important

31:46

is rheumatoid arthritis.

31:49

Septic arthritis. Complicating rheumatoid arthritis is a

31:52

very serious complication.

31:55

It may involve a single joint or multiple joints,

31:58

and to the clinician it is a diagnostic dilemma.

32:02

Are we dealing simply with an exacerbation

32:04

of rheumatoid arthritis

32:06

or is there a secondary septic arthritis going on?

32:10

Some of the helpful findings that we look for would be

32:14

a sinus tract leading from the infected

32:16

joint to the skin surface.

32:18

Rarely by the way that occurs in rheumatoid arthritis alone,

32:22

okay, called sinus tract rheumatism

32:26

or a nearby septic bursitis might help you

32:29

make the diagnosis.

32:30

Years ago we tried to figure out what might be some

32:34

of the imaging findings that would tell you the observer

32:37

that rheumatoid arthritis was being complicated

32:41

by septic arthritis.

32:42

And here are some of the things we came up with.

32:45

Rapidly enlarging joint effusion, yes,

32:47

that can be rheumatoid

32:48

but always consider septic arthritis, joint space widening.

32:53

That is if the joint is now

32:55

and then all of a sudden it widens going

32:57

to increase fluid in the joint.

32:59

Another sign sinus tracts, involvement of adjacent per se

33:04

and of course soft tissue abscess formation.

33:07

Here I show you an example of rheumatoid arthritis

33:10

and septic arthritis involving all of the compartments

33:15

of the wrist with extensive synovial

33:17

proliferation shown here.

33:19

Probably rice body is also present within those

33:23

compartments of the wrist.

33:25

Now there's one other exception that I wanna mention that

33:28

where the rule of monoarticular involvement may be violated

33:34

and that is when you're dealing with spread

33:36

of infection from one joint to a nearby joint.

33:40

And here's a list of some of the places

33:43

where I have seen this through the years.

33:46

The one I'm gonna emphasize with this example

33:49

of septic arthritis of the glenohumeral joint is

33:52

the this particular region, the shoulder region here,

33:56

the infection began within the glenohumeral joint.

33:59

Note, the marginal erosions involving the humerus, the loss

34:02

of joint space, you'll note the elevation

34:05

of the humeral head with respect to the glenoid,

34:08

the narrowing of the acromial humeral distance that relates

34:13

to the infection now destroying the rotator cuff.

34:17

Because of that,

34:18

there is now a septic subacromial subdeltoid bursitis.

34:23

Note the swelling in this region

34:25

and from there, the infection has spread into the

34:28

acromial victus joint.

34:31

So think for a moment if you are the

34:34

radiologist observing this particular case

34:37

and you see polyarticular involvement, humeral joint,

34:42

acromioclavicular joint,

34:43

you may steer away from the diagnosis of septic arthritis.

34:47

But keep in mind here, as in other locations

34:51

that I've emphasized on in the list on the left,

34:54

the infection may spread from one joint to a nearby joint

34:59

becoming polyarticular in appearance.

35:04

Now, before we move on from this section,

35:07

let me just also show you a couple of examples of specific

35:12

disorders that can lead to septic arthritis

35:14

or sometimes osteomyelitis as well

35:17

that have a somewhat distinctive appearance.

35:21

The first of these is Lyme arthritis

35:23

described initially in the northeast section

35:26

of the United States.

35:27

Now we know it is worldwide in distribution,

35:31

seen more often in children,

35:32

particularly in the summer caused by a pyro

35:36

and often transmitted by a specific type of tick.

35:40

One of the clinical findings is a very

35:43

characteristic skin lesion.

35:44

I show you that at the top right

35:48

monoarticular involvement tends to dominate,

35:51

but a few joints may also be involved in the major findings.

35:54

Shown here in this example

35:57

from Bruno Vanderberg is a large joint effusion.

36:00

You may not have much going on in the bone,

36:03

but involvement of the lymph node shown nicely in this

36:06

example and in some cases

36:09

myositis soft tissue involvement may be seen.

36:12

So this is Lyme Artis.

36:15

The second specific disorder I would mention is madura

36:20

infection, often called mycetoma.

36:23

We think of this typically as occurring in the foot

36:25

as shown in this particular example.

36:28

It's a granulomas fungal infection.

36:31

It is worldwide in distribution, dominates in India

36:35

and a few other count, uh, countries,

36:38

and typically produces soft tissue infection

36:41

that may contaminate joints and bones.

36:44

One of the characteristic findings emphasized in an article,

36:47

and I show you that article,

36:48

that top right is called the.in circle appearance.

36:53

You can kind of see it here,

36:55

a higher signal circle in the middle of it, a dot.

36:59

This would be Madea Foot.

37:00

Here's another example recently published in the literature

37:04

shown by a T two fluid sensitive sequence

37:07

and a gadolinium sequence on the right.

37:09

Beautiful, beautiful example of the dot encircle appearance.

37:14

And here on the dura knee, a case we showed on a film panel

37:19

of the International Skull Society a number of years ago.

37:22

Difficult diagnosis

37:24

unless you're aware of the.in encircle sign

37:27

shown beautifully in this example.

37:31

We're gonna move on to part three

37:33

and talk briefly about subacute and chronic osteomyelitis.

37:38

There are three basic imaging findings

37:40

that generally indicate that the infection is subacute

37:44

or chronic in nature and it is likely active.

37:47

The first of these is the brody's abscess.

37:50

The second is necrotic bone or bone sequestrum.

37:55

The third is dominate a dominating bone proliferation,

37:59

we'll call it bone sclerosis.

38:01

So let's look at each of these three features.

38:05

The first is a brody's abscess.

38:08

This is a sign of subacute

38:09

or chronic osteomyelitis indicating at least histologically

38:14

an active infection typically seen in the tubular bones

38:18

of the lower extremity, especially the tibia,

38:22

especially the lower end of the tibia.

38:25

It produces a radiolucent lesion shown here,

38:29

dimly well-defined with a thin

38:32

or sometimes broader sclerotic margin.

38:36

One of the characteristics of it is its elongated shape.

38:40

It can extend over a considerable distance shown here in the

38:44

proximal tibia.

38:46

Now there are some specific findings.

38:48

We look for the first of these, I'm gonna call the tra sign.

38:55

One of the things that we can see

38:56

with the Brody's abscess is a tract,

39:01

a narrow channel leading from it into three basic

39:05

ways or directions.

39:07

The first of these would be to the fsis.

39:10

The second would be beyond the fsis in the immature skeleton

39:14

or to the joint as shown here in my diagram.

39:18

And the third would be to the surface of the bone.

39:22

So if you see a well-defined lytic lesion

39:25

with a sclerotic margin elongated in shape with a tra sign,

39:29

that's pretty good evidence.

39:30

You're dealing with a Brody's abscess.

39:34

I show you an example here in the mature skeleton

39:37

of a brody's abscess involving the distal tibia

39:41

with a track leading into the joint producing

39:44

a septic arthritis.

39:46

I show you another example here

39:50

in the slightly immature skeleton

39:52

of a brody's abscess extending

39:54

and violating the posterior cortex extending into the joint

39:59

as well as into the adjacent soft tissues.

40:01

Note the tract shown particularly by the arrows here,

40:07

this arrow and this arrow

40:09

indicating a very important finding that we look for.

40:14

There is a second finding that we can see typically

40:19

on a T one weighted image and it's called a penumbra sign.

40:23

Typically it is a lesion with lower signal centrally

40:27

and an area of slightly higher signal at the periphery.

40:33

Now there are other things that do this,

40:35

but with the penumbra sign of infection,

40:38

that outer shell tends to be thick and irregular

40:41

and that will help you in documenting in fact a

40:45

Brody's abscess.

40:47

This is an old case that's shown by T one weighted image

40:50

and gadolinium enhanced images.

40:52

A lobulated brody's abscess

40:55

with a positive penumbra sign on the T one weighted image.

41:00

Less commonly a brody's abscess may involve the cortex.

41:04

And in that situation we do have a differential diagnosis

41:08

that comes to mind, the main one being an osteo osteo.

41:13

Here I show you on the left images

41:15

of an intracortical abscess involving the

41:20

posterior region here producing a well-defined radio area

41:25

with sequestered bone.

41:27

Some periosteal reaction.

41:29

You can see that nicely here in this case,

41:32

not looking exactly like an osteoid osteo,

41:35

but you can imagine there might be

41:37

problems in certain cases.

41:40

Here I show you an example

41:41

of an osteoid osteo involving the cortex

41:45

of the posterior portion of the femur with considerable

41:48

perio osteo new bone formation.

41:52

The third cause of a lucency in the cortico

41:55

of course is a stress fracture,

41:57

but typically it has a linear appearance which will help you

42:01

in accurate diagnosis.

42:05

The second sign of chronicity is sequestered bone.

42:08

This is necrotic bone, often present

42:12

in a brody's abscess derived from the cortex.

42:16

Here's what it looks like with MR imaging

42:18

and the proximal femur

42:19

and then a case sent to me

42:21

by Lee Rogers showing you involvement of the distal radius.

42:25

You'll note in all these cases the abscess

42:28

and within the abscess you can see the region

42:33

of sequestered bone indicating certainly

42:37

that the infection is likely active.

42:41

Now if we're dealing with sequestered bone indicating at

42:44

least microscopically activity of the chronic osteomyelitis,

42:49

the body may try to rid itself of the infection

42:53

and the way it does.

42:54

So it creates an opening,

42:56

that opening called a cloaca in the cortex

42:59

and in the living new bone called the involucrin.

43:03

And if indeed the sequestered bone is small enough

43:06

that may be displaced from the medullary cavity.

43:09

And if a sinus tract arises, which it often does,

43:13

it may be displaced from the body itself.

43:17

When I worked at the VA hospital in San Diego,

43:20

I can recall on two

43:21

or three occasions where a veteran would come in,

43:25

the veteran had chronic osteomyelitis that had been draining

43:29

for years and he or she noted a piece of bone in the bed

43:34

or on the carpet, brought it in.

43:36

That was sequestered bone delivered spontaneously from

43:40

the infected area.

43:42

Now to show you some nice examples of this,

43:45

mark Kran dorf sent me this particular case years ago.

43:50

You can see here a, a chronic infection

43:53

of the proximal humerus.

43:55

You can see the sequestered bone,

43:57

you can see the opening in the surface of the bone,

43:59

the cloaca, and you can see the lucrum below

44:03

that particular opening.

44:06

I show you another example.

44:07

This is from the San Diego Museum of Man.

44:10

This is a old prehistoric specimen showing you chronic

44:15

osteomyelitis involving the tibia.

44:17

Note, the enlargement of the bone.

44:19

You can see within it a piece of sequestered

44:23

or necrotic bone, the cloaca.

44:25

And in this particular example,

44:28

a sinus tract was indeed present.

44:30

Here is the mummified skin overlying the site

44:34

of tibial infection.

44:37

Another sign of chronicity is dominant bone sclerosis.

44:41

Typically this is seen in cases of subacute

44:44

or chronic osteomyelitis.

44:46

It may become extensively uh, involved.

44:50

You can see here in the specimen of what it might look like.

44:54

The cortex becomes thickened,

44:56

the periosteal new bone becomes mature

45:00

and the areas of lysis are not a dominant feature.

45:04

Now this has been said

45:05

to occur particularly in the NAIC bones,

45:08

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

45:11

Shown in one of our cases in the mandible

45:14

and then taken from the literature showing you

45:17

what this might look like.

45:18

We tend to call this GA rays proliferative peros titis

45:23

or gare rosing osteomyelitis.

45:26

So a number of years ago I tried

45:28

to figure out exactly why we call it that.

45:31

I found GRE's original article 1893

45:35

and some other articles that emphasized

45:38

that when he described this proliferative perio titis,

45:42

he was talking mainly about tubular bone involvement.

45:46

He only had three cases

45:48

in which the NAIC bones are involved.

45:51

So although we call this GARE proliferative

45:54

or rosing osteomyelitis, he never really

45:58

specifically described osteomyelitis involving

46:02

with this pattern involving the mandible or the maxilla.

46:07

Chronic recurrent multifocal osteomyelitis is an interesting

46:12

entity misnamed

46:14

because in most of the cases there is no infection going on.

46:18

It tends to involve multiple bones,

46:20

often involving the young children,

46:23

adolescents and teenagers.

46:26

And of the sites that are involved,

46:27

typically it is the tubular bones of the lower extremity

46:31

that are involved, especially the femur

46:34

and tibia shown in my diagram in the middle.

46:37

When you look at this with imaging studies,

46:39

classically it is the metaphyseal segments

46:42

of the bone that are involved.

46:44

I show you an MR image taken from the recent literature.

46:48

So what you may see the abnormalities,

46:50

which involve multiple bones, sometimes fairly symmetrical.

46:55

Now what's interesting about this entity are few things.

46:58

Number one, involvement

47:00

of the clavicle is not unusual, okay?

47:05

The pelvis also may be involved.

47:08

The second is the association

47:10

with pustular skin lesions, right?

47:13

Classically pustulosis palmaris a plant terrace,

47:17

but also something that I'll show in the next slide known

47:21

as the SRO syndrome.

47:24

Now these are pustular skin lesions

47:26

that may in fact include pustular psoriasis,

47:29

but the bone involvement tends to be non-infectious.

47:34

Here's an example from years ago

47:36

that came from the Children's hospital in San Diego sent

47:39

over to us at the VA as a case

47:42

of viewing sarcoma, which it was not.

47:46

This is chronic recurrent multifocal osteomyelitis shown

47:51

by imaging in in this particular example.

47:55

Now, if we deal with Safo syndrome, we can see in fact a lot

47:59

of the names that have been applied

48:01

or associated with this particular syndrome.

48:06

SAFO stands for synovitis, acne, pustulosis,

48:11

hyper osis, and osteitis.

48:14

Here's an example of what the skin lesions look like in

48:18

that particular disorder.

48:19

So with those pustular skin lesions,

48:23

you may develop changes in the skeleton

48:26

and those changes typically are dominated by bone sclerosis.

48:31

The site of involvement varies according to the age

48:34

of the person in the younger person,

48:37

as I've indicated it may be tubular bones, the clavicle

48:40

and older people involvement of the chest wall is,

48:43

is often seen.

48:45

Hence you can see the variety of names

48:47

that have been associated with this particular syndrome.

48:51

Here's an example in an older person

48:53

of chest wall involvement, medial lens of the clavicles,

48:58

the sternum, the upper ribs shown here

49:00

with conventional radiography and MR imaging.

49:05

Finally, in the last couple of minutes,

49:07

just a brief words about complications

49:10

and particularly one squamous cell carcinoma

49:14

of the sinus tract

49:15

that may in fact complicating longstanding

49:19

draining osteomyelitis.

49:22

We talk about the marginal ulcer,

49:24

which is a chronically slowly growing pre-malignant

49:29

skin ulceration.

49:31

I've seen a number of these cases, uh, associated

49:35

with chronic osteomyelitis.

49:36

In my experience,

49:37

they're more common in the lower extremity,

49:40

especially in the foot

49:42

and over a period of time, often measured in years,

49:45

sometimes in decades.

49:48

Squamous cell carcinoma of the sinus tract may arise

49:52

and with it a poor prognosis, the likelihood in many cases

49:57

of distant metastasis.

50:00

So here I show you, draining chronic osteomyelitis

50:04

and the development of a squamous cell carcinoma.

50:08

Telling this from osteomyelitis alone can be difficult.

50:13

Clinical findings may indicate that the type

50:15

of discharge has changed in the amount

50:18

or in the odor associated with it

50:21

or an adjacent soft tissue mass may be seen.

50:25

To show you one final example of that here is an example

50:29

of squamous cell carcinoma

50:31

complicating chronic draining osteomyelitis.

50:35

Something at least they considered not common,

50:38

but certainly well known.

50:40

So what I've done in my period of time is

50:42

to review the mechanisms, imaging findings

50:45

and complications of musculoskeletal infections.

50:49

We've covered four particular areas, acute osteomyelitis,

50:54

septic arthritis, subacute and chronic osteomyelitis.

50:58

And very briefly we covered at the very end complications.

51:03

We've thus talked about mechanisms, imaging findings

51:06

and complications.

51:08

And just before I end, I would just mention

51:10

that if you are interested in MR imaging

51:13

of the lower extremity, we're doing an online course, uh,

51:17

UCSD faculty

51:19

and one scholar previous UCSD scholar will present this

51:23

material, as you can see, beginning at the end of September,

51:27

extending into the first week of October.

51:31

Hopefully some of you will join.

51:34

Thank you very much for your attention on this

51:38

and I guess we're going to

51:40

see if there are any questions about this.

51:43

Absolutely. Thank you so much for that great lecture Dr.

51:46

Resnick. Yes. At this time if you've got a question,

51:48

go ahead and put it into that q

51:50

and a feature so we can get through as much

51:53

as we can before we close.

51:55

Okay. Dr. Resnick, how to differentiate septic bursitis

52:00

with secondary osteomyelitis and vice versa.

52:04

Well, as you know, there are a lot of causes of bursitis

52:08

and so, uh, many times you're trying

52:11

to decide is it idiopathic, is it related to stress?

52:14

Is it related to an underlying rheumatoid like disease?

52:18

Um, I think particularly if we're having an enlarging bursal

52:23

sac with increasing fluid, especially in a superficial bursa

52:27

and I emphasize the Elon bursa

52:30

and the pre patella bursa, you ought

52:32

to consider septic bursitis.

52:35

And once you've done that, always consider a tuberculosis

52:39

and the differential diagnosis.

52:41

Once we have septic bursitis, carefully look at the surface

52:46

of the adjacent bone, whether

52:49

or not there is periosteum, bone formation, cortical uh,

52:53

erosion or destruction that would indicate

52:56

that osteomyelitis is complicating that septic bursitis.

53:03

Thank you. Can you say how

53:05

to differentiate osteomyelitis from neuropathic joint?

53:11

Yeah, I emphasized one fine, I

53:13

to be totally honest about this.

53:15

I find it difficult in many cases in the diabetic.

53:20

The first thing I want to emphasize is the presence

53:22

of soft tissue ulceration that in the vast majority of cases

53:27

of diabetic infection,

53:29

there is an overlying soft tissue ulcer.

53:32

With neuropathic disease alone, that is often not the case.

53:37

Okay? So that I think is particularly important.

53:41

If there's an overlying soft tissue ulceration,

53:45

you wanna study carefully the sub bones.

53:49

If for example, there is loss

53:51

or a fuzzy outline to those bones

53:54

with conventional radiography

53:56

or with CT scanning,

53:58

I would really be concerned about osteomyelitis.

54:02

Neuropathic bone fragmentation tends to be better defined

54:06

and the surface of the bone may in fact be maintained.

54:10

But then as I emphasize, there is the ghost sign described,

54:14

uh, by, uh, on T one weighted MR images as a loss

54:19

of the cortex

54:20

or a loss of the subc conval bone plate

54:24

as a fairly distinctive feature of osteomyelitis,

54:28

positive ghost sign and osteomyelitis, the absence

54:31

of a ghost sign with neuropathic disease without, uh,

54:35

additional infection going on.

54:40

You killed two questions with one answer there.

54:43

The next question was about the ghost sign.

54:45

Thank you so much. How often are you going

54:48

to radionuclide imaging for confirmation of infection?

54:53

Yeah, I would say right now less than we did

54:56

so in the past, and I think that's

54:58

because with Mr Imaging,

55:00

not only do we have increased sensitivity when compared

55:03

to CT and conventional radiography,

55:07

but indeed there are some fairly specific, uh, findings.

55:11

I think bone scanning

55:12

and uh, specific, uh, types of scanning

55:15

for infection are important,

55:17

but I would say overall we're using it less often than we

55:21

did in the past.

55:26

Conundrums pen, sorry, conundrum sign, darker periphery

55:30

or brighter periphery on T one on the, yeah,

55:33

the image you showed, it looked typo intense.

55:35

Yeah. So let me emphasize that sign again.

55:38

When it was originally described, I think it was said

55:40

to be specific for osteomyelitis, but it is not.

55:46

The penumbra sign in osteomyelitis consists

55:49

of a thick irregular rim of

55:53

slightly higher signal.

55:54

It's still low signal,

55:56

but it's slightly higher signal than the contents within

56:01

that particular cyst like area.

56:04

So the central part is of lower signal, the outer part is

56:09

of slightly higher signal,

56:10

we'll call it intermediate signal.

56:12

And the reason it's not specific is that when you deal

56:16

with cyst alone ganglion cysts

56:19

or synovial cyst, you will see, in fact you have a thin rim

56:23

of slightly higher signal around the fluid.

56:27

But it is the thicker irregular rim that we see

56:32

that I think is much more specific for osteomyelitis

56:36

and we call it the penumbra on.

56:41

Would synovial proliferation

56:43

or panis lead more to rheumatoid arthritis or osteomyelitis?

56:49

Well, I think, uh, panis, uh, which is something we see

56:52

with synovial proliferation is, uh, something associated

56:57

with a variety of articular diseases.

57:00

Rheumatoid arthritis, all of the spondyloarthropathy,

57:05

septic arthritis, all can produce inflammation,

57:09

proliferation of the synovium and panis,

57:12

and that panis can then extend into the marginal areas.

57:15

Those are the marginal erosions,

57:17

and then attack the cartilage.

57:20

Now it's of interest when we kind of talk about

57:23

septic arthritis, something I didn't emphasize when dealing

57:27

with bacterial infection,

57:29

typically the panis grows across the surface

57:32

of articular cartilage

57:34

and then through enzymatic degradation, rapid loss

57:37

of joint space, when we deal with tuberculous

57:41

or fungal infection, the panis often grows

57:46

between the cartilage and the subc chondral bone.

57:49

So the cartilage is maintained for a while.

57:51

The joint space is maintained for a period of time.

57:54

And what you may see particularly in tuberculosis

57:59

is erosion of the subc conval bone plate and sub bone

58:03

and preservation of joint space.

58:05

And that's the histologic reason,

58:07

but that is an important sign of fungal disease

58:10

and tuberculosis.

58:12

Right. We'll do two more and then we'll wrap.

58:16

Um, is there a case

58:18

where osteomyelitis can mimic polycystic

58:21

fibrosis, dysplasia in children?

58:24

Um, I would say, I'm sure there are cases where

58:29

that has occurred, not in my experience,

58:32

but I'm not gonna say that's not a possibility.

58:36

All right. Can we differentiate osteomyelitis from

58:39

osteonecrosis, particularly in patients with sickle cell

58:44

Difficult diagnosis to make?

58:46

And that's something, there are many, many articles

58:49

that have written about this talking about different imaging

58:52

methods that might help you bone scanning and others.

58:57

I would say in many cases that differentiation

59:01

is, uh, is difficult.

59:02

And then one other point as I illustrated, uh,

59:05

in this particular talk is if you're dealing

59:08

with a septic arthritis in certain locations,

59:11

you may elevate the intraarticular pressure

59:15

and interruptive vascular supply to the nearby epiphysis,

59:19

the femoral head comes to mind.

59:21

And then you have both septic arthritis infection

59:24

and osteonecrosis occurring at the same time.

59:28

Well, Dr. Resnick, thank you so much

59:29

for answering all those questions.

59:31

There's tons more, but we gotta get you outta here.

59:34

And thank you so much to everyone else for participating

59:37

and, um, putting in all those questions.

59:40

I apologize we can't get to all of them.

59:42

There were a couple questions about the lower extremity

59:45

conference and that is in September

59:48

and we are posting a link in the chat

59:50

and there will be one in the email follow up.

59:53

You can also access the recording of today's conference

59:55

and all previous noom conferences

59:57

by creating a free MRI online account.

59:59

We'll also email a link out to that replay later today.

60:02

Be sure to join us next week on Tuesday,

60:05

July 2nd at 12:00 PM Eastern, where Dr.

60:08

Raja Chabal will deliver a lectured entitled Ultrasound

60:11

Anatomy and Common Pathologies of Wrist Joint.

60:14

You can register for that@mrionline.com

60:17

and follow us on social media

60:18

for updates on future noon conferences.

60:20

Thanks again for learning with us and have a great day.