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Hello and welcome to Noon Conference, hosted by Modality

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by creating a free account today.

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We are so honored to welcome Dr.

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Steven Pomerance for a lecture entitled MRI of the hip. Dr.

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Pomerance is the CEO

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and Medical Director of ProScan Imaging, chair of Naples,

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Florida Community Hospital Network,

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and the founder of MRI Online.

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He's authored numerous medical textbooks

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and MRI, including the MRI, total Body Atlas.

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Dr. Pomerance is also an AVID conference, lecturer

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and chairs the fellowship training program in MR.

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And Advanced Imaging. We're thrilled.

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He's here today to share his expertise.

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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

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have on today's topic.

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Please remember to use that q

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

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as many as we can before our time is up.

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

1:11

Pran, please take it from here.

1:13

Again, I wanna wish everybody, uh, good morning,

1:16

good evening, and good afternoon.

1:19

I am showing you initially the 12 pounds per square inch

1:23

force that's exerted on Carl Lewis's hip as he makes this,

1:26

uh, 26 and a half, 27 foot jump.

1:30

I think it was the second or third longest long jump in

1:33

history behind at least Bob Beam's, one or second jump.

1:38

And, uh, the same thing is true

1:39

for a basketball player dunking a basketball.

1:42

It's about 12 pounds per square inch.

1:44

So the hip is a very resilient structure,

1:46

but at the same time, uh, like the shoulder,

1:50

it is supported in a pretty shallow cup

1:52

for the femoral head size.

1:54

And, um, it is sometimes not completely covered.

1:59

Today we're gonna talk about some very basic anatomy

2:03

variance in techniques.

2:05

Um, focus really on labrum

2:08

and impingement syndromes, uh, apophysis tendons,

2:13

uh, postoperative hip,

2:15

and then some of the other, uh, diseases

2:18

that have a predilection for the hip will have

2:20

to stay for another day.

2:22

But those would include things like lipo, mixo, fibroma, uh,

2:26

or fibrous tumor of the hip, which

2:28

for some reason loves the femoral

2:30

metaphysis more than any other.

2:32

Um, let's begin with some anatomy and variants.

2:38

On the left side of the hip, I've got an orange.

2:41

And you see how the orange is oriented. It is verted.

2:45

In other words, the posterior aspect of the acetabular rim,

2:50

the back of the orange, is more lateral than the anterior

2:52

aspect of the orange putting, putting the hip in

2:56

anted, uh, position.

2:59

Let's start with our first variation.

3:01

And as you look at Mrs, there are variable degrees

3:05

of notching in the superior aspect of the acetabulum, one

3:09

of which is seen beautifully on this sagittal.

3:12

The diagram is a coronal,

3:13

and on the sagittal you see this little defect.

3:16

Um, it's a symmetric defect.

3:18

It's near the 12 o'clock position,

3:21

and it is in no way surrounded by edema or chondromalacia.

3:25

And this is the fusion site of the tri radiate cartilage.

3:28

You see it in the axial projection as well, uh,

3:31

close to the midline.

3:32

In this 14-year-old

3:33

with groin pain whose groin pain was in no way related

3:36

to this normal variant called the stellate defect,

3:40

or it's, it's a pseudo osteocondral defect.

3:44

It should be absolutely solitary.

3:47

And sometimes you will actually see a fibrous band

3:51

as depicted here in red, coursing over to the fovea capita.

3:54

And then it is called a, uh, stellate complex.

4:00

Here's an example of this stellate crease,

4:02

namely the stellate crease being the,

4:04

the defect in the cartilage

4:05

and the sagittal projection on a two millimeter 3D GRE.

4:09

And once again, it is isolated

4:11

and solitary with no surrounding edema.

4:14

Uh, close to the 12 o'clock position.

4:18

Now, cartilage in the hip, the sagittal view is accretive.

4:22

So some parts of the hip, the femoral part is thicker.

4:24

Some parts of the hip, the acetabular part is thicker,

4:28

but together they should make up about three millimeters.

4:31

And the overall width in a young,

4:34

healthy individual should be pretty consistent.

4:36

For those of you that are blessed with extraordinary vision,

4:40

you may be able to see this very thin black line

4:43

that choruses between the acetabular

4:46

cartilage and the femoral cartilage.

4:48

And that is the collapsed capsule of the hip.

4:52

Let's talk about some key ligaments now,

4:55

and, uh, I'm gonna rattle them

4:57

off and then show them to you.

4:59

The most important is the anterolateral ileal fal ligament

5:02

of Bigelow, also known as the Y ligament.

5:06

Perhaps it should be called the upside down y ligament

5:08

'cause it is inverted.

5:10

It, it reinforces the anterior capsule,

5:14

and there are two bands to it, not not all that important.

5:18

Another name given to this ligament is the Ileo trocanter

5:21

ligament that's used more commonly in Europe.

5:24

Then we've got the capsular zona orbicularis ligament,

5:27

which are circular fibers

5:30

that are more consistently seen posterior than anterior,

5:33

but very well seen arthroscopically.

5:35

And they define everything above is intraarticular.

5:38

Everything below is extra articular,

5:41

and when you fracture intraarticular, your risk

5:44

of a vascular necrosis goes up.

5:47

We have the issue of femoral ligament.

5:50

It is a straight posterior ligament along the back

5:54

of the hip, and it's divided into a superior inferior band.

5:58

And finally, the pubal femoral ligament,

6:00

which is found in the anterior inferior joint,

6:02

and a section of it is also known in the sagittal projection

6:06

as the transverse ligament.

6:09

Let's take the most famous of all these ligaments.

6:11

The ligament terrace.

6:13

Here is the anatomic specimen of the tes.

6:16

And as it comes up, you can appreciate

6:19

but better on MRI, that it breaks into two heads,

6:22

a pubic head and an ischial head.

6:24

Do not confuse the space in between the two heads

6:27

for longitudinal tear for

6:29

that is nothing more than intervening capsular tissue.

6:33

Now there are, there are no sulcus that you should see

6:37

up high in the 12 o'clock position

6:40

and just anterior to it in, in the hip.

6:43

Uh, you, you may, may see a little bit

6:45

of curvilinear signal there, but not much.

6:47

In the sagittal projection, though,

6:48

it's very common to see a recess.

6:51

Some might also call it a sulcus.

6:53

And, um, that is located, uh,

6:56

between the iliofemoral ligament, the ligament of Bigelow

7:00

and the anterior labrum.

7:01

And, and you see right there,

7:02

it's usually vertically oriented.

7:04

It, it may have a curve linear top,

7:07

but when you're scanning coronal, you will,

7:08

you will not see, uh,

7:10

this recess very often in the coronial projection.

7:15

Now, here is some, uh, anatomy that's,

7:19

that's highlighted together.

7:21

We've got aray, thickened ligament, terries,

7:24

and then a, a perfectly normal ligament terries.

7:27

One of the interesting feature

7:28

for the ligament tes is it arises from a ligament.

7:31

So it's a ligament to ligament origin,

7:34

but a bony insertion with this arthroscopic technique,

7:39

Mr, you can see the ileal ligament

7:41

and then transition into the zona orbicularis,

7:45

which defines the intraarticular hip from

7:48

the extra articular hip.

7:50

And as it continues to course, over becomes the

7:54

PBO femoral ligament and the sagittal projection.

7:56

There's a small segment of it called

7:58

the transverse ligament.

8:00

Now, even though these aren't ligaments, they're ligament,

8:02

like they're formed fibroelastic tissue,

8:07

and these are synovial folds or plicate.

8:12

You have the synovial phone, a fold

8:14

of white rec on the left,

8:16

and you've got a pectin foveal fold,

8:19

which I have seen resected

8:21

as a quote unquote snapping clicka when indeed it was not

8:25

the cause of the patient's clinical syndrome.

8:26

And because it carries blood supply, the patient ended up

8:30

with a VN not a very good outcome at all, resection

8:34

of a normal variant structure.

8:36

So you must be aware of its presence.

8:39

We also have the ligament to ligament origin

8:42

of the ligamentum tarries

8:44

with its two heads not showing its attachment.

8:48

Here's another weird fold.

8:50

There is a fold in this patient that has occurred along the

8:54

labrum that looks like a labral tear.

8:57

The key is that you can keep following it

9:00

as a linear structure as opposed to an isolated structure

9:04

as would be in the labrum.

9:06

Another variant is known as the iliac or iroc, uh, muscle.

9:10

It originates from the capsule.

9:12

And anterior inferior iliac spine extends

9:15

to the lesser trocanter.

9:16

It is a stabilizer is found, uh, with increased frequency

9:21

and, and hip dysplasia.

9:22

And sometimes you may see some weird patterns

9:25

of fatty infiltration in adjacent muscles.

9:28

Now, a very important, uh, structure

9:31

that is not abnormal in the hip is the sub labral sulcus.

9:35

We don't get very, very many. Sub labral sulcus is up high.

9:39

It's in fact it's quite rare, unlike the shoulder

9:43

where sub labral sulcus is and sub labral foramina abound.

9:48

So let's just get you oriented. Here is the femoral head.

9:52

Here's the ace tablum.

9:54

And as you go from cran to coad,

9:56

look at this labrum right here

9:58

and look at this little, uh, little interface.

10:01

And all of a sudden it starts

10:02

to get a little bit deeper right about there in the anterior

10:05

inferior quadrant, and it stays deep.

10:08

So anterior inferior location is typical of the sulcus.

10:12

At around eight o'clock, it fades.

10:14

As you move up, it gets more shallow. And that is a rule.

10:18

It it, it it is usually rounded rather than sort

10:21

of linear and knife blade.

10:23

It has a little bit of curvature to it.

10:25

No cysts should accompany it. It has a shallow depth.

10:29

And, um, it is found s laterally.

10:32

Um, when it is seen superiorly, it's kind of off

10:35

to the side, but,

10:37

but again, uh, superior ssci

10:41

that are visible on MRI are uncommon, uh, to rare.

10:46

Uh, the, the hip, um, uh, when it's dysplastic,

10:51

uh, should have a labrum,

10:54

but the labrum may have a higher, higher incidence

10:56

of a sulcus that extends up more proximally.

10:59

But that's a whole different subset of individuals.

11:02

Now, the basic technique is

11:03

to turn the patient's feet inward, to promote,

11:06

promote pronation, and to see the greater tro caners.

11:10

And you can Velcro strap the feet together.

11:14

Uh, the patient likes going in feet first if possible,

11:18

especially if they're a little bit claustrophobic.

11:20

And you place a sponge between the ankles

11:23

to maintain the inward position of the feet and toes.

11:26

Now, another anatomic aspect of a hip that's unique to it

11:31

is the shape

11:34

that yields a an abnormal alpha angle.

11:37

What, what is an alpha angle?

11:38

Well, simply stated, an alpha angle is the measurement

11:43

of their transition point where the head becomes the neck

11:46

or set another way.

11:48

In some patients whose alpha angle is abnormal, the head

11:52

and neck transition will be too big cam impingement syndrome

11:55

or too narrow, in other words, thin

11:59

and piner impingement syndrome.

12:01

So how do we, how do we eyeball this and or measure it?

12:05

We put a.in the center of the femoral head.

12:07

We dissect the femur.

12:09

So d and D should be equal, these,

12:12

these measurements right here.

12:14

And then we decide, we decide where the transition is from

12:19

concave to convex.

12:20

In this case, there really wasn't much of a transition,

12:23

and so we, we deemed the transition from head

12:27

to neck over here, and then we would measure this angle,

12:29

which turned out to be over 60 degrees.

12:32

Now, most professional athletes have

12:34

a hip that looks like this.

12:35

They have higher alpha angles

12:38

because they have thick head neck junctions,

12:40

and perhaps that has something to do

12:42

with why they are good athletes,

12:44

especially true in studied in, uh, United States, male

12:49

American football quarterbacks.

12:53

Now, to measure the alpha angle,

12:54

you don't just get an axial, you must get

12:58

a coronal oblique

13:01

or an axial oblique, whichever you choose to call it,

13:03

down the long axis of the femoral neck.

13:05

Otherwise, your measurements are gonna be off

13:07

a hundred percent of the time.

13:09

Now, in the hip, we do orthogonal projections.

13:11

We do sagittal, coronal and axial.

13:13

But when we are pursuing the labrum in every single case

13:18

of hip pain, we are performing radial imaging

13:21

through a center in the femoral head at a series of 10

13:26

to 15 degree increments so that we cut the hip into a pie.

13:31

For those of you that wish to learn about the technique

13:35

of radial imaging

13:36

and how to do it properly rather than take up too much time,

13:39

the paper by Petra in 2013 in Radiographics will help you

13:45

immensely and also help your

13:47

technologist do this the right way.

13:49

So here is just that.

13:50

Here is the coronal oblique, right, coronal oblique

13:53

or axial oblique, depending upon how you like to name it.

13:57

And here is a patient with a labeled tear.

14:00

And now you can see the cystic portion

14:01

of the labeled tear right here and a straight axial.

14:05

But when you do the oblique coronal here is one

14:08

of the oblique coronals.

14:09

There's a horizontal component of the tear.

14:11

There is the vertical portion of the tear.

14:14

Remember, there are no sci in the anterior superior quadrant

14:18

except perhaps in hip dysplasia.

14:21

So now let's take a sagittal oblique.

14:24

How do we get this sagal oblique?

14:26

Well, rather than going straight up

14:27

and down, we went this way slightly angled,

14:32

and then from the sagittal oblique we put a.in the center

14:35

and we proceed to get a series

14:36

of slices every 10 to 15 degrees.

14:39

We're mostly interested in the 12 o'clock to

14:43

anterior mid position, which is where most

14:45

of the symptomatic, uh, tears occur.

14:47

But I, but I will say even on straight sagittals,

14:51

non angled sagittals, 10% of all label tears are only seen.

14:56

Sally. Here's an example of a group of radials, uh,

15:01

that require, require no intraarticular contrast.

15:05

We do not routinely give intraarticular

15:09

contrast for labeled tears.

15:11

In fact, we find it a detriment.

15:13

Now, if we have a high suspicion

15:15

and we have a normal MRI, then yes,

15:17

perhaps we'll bring those patients back.

15:19

But that i, I would say now that occurs less than 100, 2 50

15:23

to 105, one in 500 in our practice.

15:28

Here is an example of a tear.

15:30

This one's horizontal, same tear, a little shorter,

15:33

but a little stubbier horizontal, uh,

15:36

a little nubey looking a little bit round and then vertical.

15:40

So yes, they do cha change shape

15:42

depending upon where you are.

15:43

But each one of these was a different radial angle

15:46

depicting the contour of the tear.

15:48

And, and this is a hundred percent a, a radial tear.

15:52

So let's talk about label tears and classifications

15:55

and some of the descriptors.

15:56

Let's begin with this slide drawn by our esteemed, um,

16:00

artist in our, in our group, uh, Paul Bohart.

16:04

And first you have the normal labrum.

16:07

And, and there is a little sulcus laterally, not not

16:10

between the labrum and the acetabulum,

16:13

but between the ileal femoral ligament

16:16

and the Bigelow ligament

16:17

and the labrum you've already saw seen an

16:19

example of it, Sally.

16:20

It happens coronal.

16:22

And this is the Bigelow recess or the iliofemoral recess.

16:26

Um, you can get accessory ossicles in this neighborhood.

16:30

We used to say they were congenital or developmental.

16:33

We now know that most of these, many of these are,

16:36

are broken spurs.

16:39

You can get osteophytes, uh, you can get ossification

16:41

of a labrum, not, not very common.

16:44

Most of the labral tears that we see are vertical tears.

16:48

We call them vertical longitudinal tears.

16:51

Now, a cleft or a sulcus is u usually gonna be

16:54

seen as you come down.

16:56

So I can't really depict this in the diagram,

16:57

but as you come from cranio to co add,

17:00

and you see nothing this little rounded

17:03

but vertical, uh, abnormality

17:05

or defect with a rounded top is gonna appear and get deeper.

17:09

As you move closer and closer

17:10

to the anterior inferior quadrant, you may get a tear

17:14

or stripping of the iliofemoral ligament,

17:16

or you may get a labrum

17:18

that is just simply detached from the

17:20

acetabulum and hylan car.

17:22

So-called chondro osseous, uh, separation injury.

17:26

Now, there are a lot of grading systems for lab tears.

17:29

I don't want you to learn any of them.

17:31

I just want you to kind of understand

17:33

how the labrum goes awry.

17:37

The, the Zer or Czerny classification, um, uh,

17:41

has a few of these descriptors.

17:43

But, but I, I'd like you to break it down this way.

17:46

Uh, there's a morphologic change in the shape of the labrum.

17:49

There's some intrasubstance signal in the labrum.

17:52

There's an abnormality that communicates with the surface

17:57

of the labrum, either the superior surface

17:59

or mostly the inferior surface.

18:01

And it may or may not involve the labrum

18:05

and extend into the hylan cartilage, which is a, a serious,

18:10

a more serious type injury.

18:12

When all is said and done, you may also have injuries

18:15

of the adjacent ileal femoral ligament or capsule.

18:18

Here's an example of somebody with

18:21

a communicating surfacing tear.

18:23

I don't care about the label,

18:25

I don't care about the grading system or the name.

18:28

You'll be talking to yourself.

18:29

They won't know what you're talking about.

18:33

Ileal femoral ligament attaching to the, the neck

18:38

of the femur and becoming the zona orbicularis

18:42

and then coursing into the pubal femoral ligament

18:45

and the transverse ligament.

18:48

Here's a deep vertical tear in a child, uh,

18:52

saved a little bit by the capsule here laterally.

18:55

Otherwise the labrum would be floating away.

18:57

So detached, uh, near full depth, but not displaced.

19:01

A very serious tear clock faces.

19:05

And the sagittal projection, um, I tend

19:08

to use throughout the body.

19:10

The lower clock faces anteriorly.

19:12

So the horizontal mid equator would be three o'clock.

19:14

Doesn't matter which side I'm on.

19:17

And the back of my hip

19:18

or the back of my shoulder is going to be 12 o'clock.

19:21

You're gonna hear this all different ways.

19:23

12 o'clock in the, in the front, three o'clock in the back.

19:27

I don't care how you do it as long as you say three o'clock

19:32

anterior mid equator of the, the femoral acetabular complex.

19:36

In other words, you just tell them it's anter superior,

19:39

it's anteroinferior, and so on.

19:42

And then you can throw the clock face in there so that it's

19:46

absolutely clear what you are describing.

19:49

So here's another example now of a, of a label tear.

19:52

This one is not degenerative, it's not intrasubstance.

19:56

It surfaces inferiorly.

19:57

It's vertically oriented,

19:59

and it is associated with separation

20:02

of the labrum from the underlying bone.

20:05

In the 16-year-old 260 pound high school lineman

20:09

that went on to play for Notre Dame that had no injury,

20:13

he simply had groin pain.

20:15

And when the diagnosis of a separation,

20:19

a chondro acetabular separation was made

20:22

for his esteemed orthopedic surgeon, he did not believe it.

20:25

And so he forced us to do this arthrography,

20:27

otherwise we would not have done it.

20:30

Another way of classi classifying tears is degenerative.

20:34

Well, well, I will say almost a hundred percent

20:37

of all people that get MRIs o

20:40

of the hip have degenerative tears.

20:42

So your job is

20:43

to distinguish a symptomatic degenerative tear,

20:46

which isn't common by the way,

20:48

or maybe part of a bigger scene.

20:50

In other words, OA and chondro, ation effusions

20:53

and deformity versus a simple chronic,

20:58

uh, but, but a chronic

21:01

but deforming, uh, traumatic label tear.

21:04

And that can be a little challenging between these two.

21:06

It really depends on shape.

21:08

And in this situation, you don't have OA in this situation,

21:12

you do have oa.

21:14

This might be a younger patient,

21:15

this might be an older patient.

21:16

The easiest one is the act of tear in an

21:18

otherwise healthy person, an active traumatic tear like this

21:22

young 16-year-old, uh, high school lineman.

21:25

Uh, it is clear cut that you have a line

21:28

that does not belong there in the

21:29

anterior superior quadrant.

21:31

It cannot be a sulcus in that position,

21:33

especially in a child,

21:34

and especially in somebody without dysplasia.

21:36

So the diagnosis is immediately made.

21:39

Now, let's look at a,

21:40

a traumatic label tear versus say a

21:43

degenerative labeled tear.

21:45

And, um, I believe I have a video here showing one

21:48

of our great players from about 20 years ago,

21:51

playing in the final minutes of a preseason game

21:55

where winning a, actually it might have not been preseason,

21:58

but we were winning 33 to like six,

22:00

and they had him our best player running back a kickoff.

22:04

God knows why. Here he is.

22:05

Watch his knee strike the ground, bang right there.

22:08

I'm gonna see if I can freeze it in slow

22:10

motion and you will see.

22:13

Let's go, oh,

22:16

let's see if I can back it up just a little bit for you.

22:22

Yeah, look at that knee, see where his toe is?

22:25

His toe is out here. So his knee is in slight internal

22:29

rotation and his, his patella

22:31

and tubercle are striking the ground

22:33

to watch it one more time.

22:36

Boom. See how he's turned outward?

22:38

That is how you develop a traumatic label tear.

22:40

And he did, uh, that was the last game he ever played.

22:45

Uh, here is his coronal T one, uh, it looks like a,

22:49

a sad example of the, uh, Greek, um, philosopher

22:54

and playwright, uh, your rip

22:56

'cause we've got the rip right here,

22:57

right there and right there.

22:59

Here's the ilio femoral ligament,

23:01

but better seen on the water weighted image.

23:03

Look at that ragged, irregular.

23:05

The, the kid is 24 years old.

23:08

You, you don't have a, a hip

23:09

that's degenerated like this in a 24-year-old.

23:11

So a young person. And, uh, here it is again,

23:14

really beautifully seen on the proton

23:17

density, fat suppression.

23:19

We did not inject this hip, by the way.

23:21

This is all a effusion

23:22

that is providing the arthroscopic effect.

23:25

So there is a labral, acetabular,

23:27

acute traumatic separation.

23:29

You can see he's lost the ischial, uh, head

23:32

of the ligamentum terries.

23:34

He's got a very redundant, uh, floppy looking, uh,

23:38

pubal femoral, uh, ligament and transverse ligament.

23:43

And he decided to try the conservative route

23:46

because they told him, Hey, as a wide receiver and,

23:48

and a running back and running back kicks, you know,

23:51

you need to have that hip rotation that you would lose it

23:53

with an operation of tacking that back.

23:56

This is a long time ago. And he, he deferred.

23:59

He came out for spring training

24:01

and played one game, and that was it.

24:03

He couldn't play anymore and never played

24:05

another game in the NFL.

24:08

Here's our groin pain.

24:09

16-year-old, uh, I believe that, uh,

24:12

went on to play for Notre Dame.

24:14

Now this is how subtle they can be,

24:16

but once you have a library of cases that you've looked at

24:21

for, for years, you know

24:23

what belongs and what doesn't belong.

24:24

There's no abnormality.

24:26

Uh, there's no normal structure

24:28

that belongs in this location like this, this white thin,

24:33

razor edge band right here.

24:35

And, and here's the Axio projection

24:36

of the same patient pre and post.

24:39

You. You really didn't need this other than it shows the

24:41

tear a little deeper, the, the acetabular, uh, or,

24:46

or, uh, the acetabular label separation.

24:49

And here it is again in the axial projection.

24:52

So again, we did it for the clinician.

24:54

Um, unfortunately, um, it was positive

24:57

and it, it got repaired by a very esteemed, uh, hip surgeon.

25:02

And he went on to Notre Dame

25:03

to have a very successful career

25:06

is another kind of label tear.

25:08

And, and this one is, uh, traumatic,

25:12

although there's a very high incidence

25:14

of posterior degenerative label tears,

25:16

especially posterior superior.

25:18

And we don't get terribly excited, uh, about those.

25:22

Um, the typical labral tear is enforced abduction

25:26

and internal or as you saw in tray external rotation.

25:30

Um, but in a hip dislocation, it is almost always

25:35

a displacement of the head backwards

25:37

because you've got this thing in the back

25:39

of your body called your buttocks

25:41

that pre prevents you from getting struck in the butt

25:44

and driving the head forward.

25:46

Plus, you've got this powerful

25:48

iliofemoral ligament to protect you.

25:50

So anterior dislocations are rare, they're catastrophic, uh,

25:54

but most of the time they occur out the back.

25:56

The patients do very well without, uh, an operation, as long

26:00

as the labrum stays pretty close to home, as long

26:03

as there's not a big piece of bone that needs

26:05

to be screwed back in.

26:06

So these are treated conservatively

26:08

and it is shocking how asymptomatic they are.

26:11

They're in pain immediately for about five to 10 minutes,

26:14

and then they just get up and walk off the field.

26:17

This gentleman's father was an orthopedic surgeon.

26:21

He was working the game.

26:22

He had no idea that his son had a hip dislocation,

26:24

even though he was a sports guy.

26:26

And when we gave him the MR report,

26:28

he was a little bit incredulous, but the answer was correct

26:32

and he did do very well.

26:35

Let's talk about, uh, impingement now.

26:37

And I, I wanna I wanna show you some examples of, uh, cam

26:42

and pinch are impingement.

26:43

This is what a cam is.

26:45

A cam is an irregular rotating device.

26:48

And you see as it rotates, let's look at it one more time

26:51

as it continues to rotate, this portion drives into this

26:56

screw that is mobile and pushes the screw up.

27:00

So if, if this thing is rigid

27:02

and you rotate a bumpy structure into it, then

27:06

you're gonna start to scrape the bottom rather than compress

27:09

it upward, and you're gonna end up with erosions

27:13

and potentially lab tears.

27:16

So we're gonna talk about cam impingement,

27:17

which is common pinch or impingement, which is uncommon,

27:21

and mixed varieties which are common.

27:22

Let's begin with type one cam or FAI one.

27:28

Now you have a as ferocity with a bump in the neck.

27:32

You may have a cyst under that bump

27:33

as you bring your leg up, inflection

27:36

the bump comes in contact with the anterior labrum.

27:39

Let's keep watching.

27:42

Now, magnification shows the bump driving into the labrum,

27:46

pushing it away

27:47

and separating it from the underlying bone with an abrasion

27:51

that's occurring right behind it

27:53

that will propagate from anterior to posterior.

27:56

So you'll get this triad of a bump cyst complex,

28:00

a torn ace tablum, usually with

28:03

acetabular labral separation

28:06

and a deep erosion that occurs in the, an

28:10

superior portion of the hip.

28:13

So what does that look like on MRI?

28:15

Well, this is a coronal proton density, uh,

28:19

elegantly fat suppressed image called a spur spare special.

28:24

It goes by many different names.

28:26

Um, spectrally sensitive fat suppression would

28:29

be the scientific name.

28:30

And in the coronal projection, first of all,

28:33

you see this little black line.

28:35

That little black line is not the capsule,

28:37

it's not nothing, it's just right here.

28:40

And that is changed in the protio glycan milieu

28:44

of the free edge of the acetabular cartilage.

28:48

And with it you have a mashed superolateral labrum.

28:53

And then the third component of the triad.

28:56

So acetabular hylan cartilage injury

29:00

or abrasion labral injury.

29:03

And then as ferocity, where there's no tapering of the neck,

29:07

here's a tapered neck on the underbelly.

29:10

There is no tapered neck here, and the patient may go on

29:14

and develop a, a cyst.

29:17

Here's what it looks like in the axial projection.

29:20

Here's a normal internally rotating person

29:22

with a tapered neck, and here's one without a tapered neck.

29:25

And you see how it drives into the free edge

29:28

of the acet tablum.

29:29

Now, sometimes it could be extremely subtle.

29:32

You might look at this and say, well, the neck looks fine.

29:34

No, it doesn't. It's actually straight

29:39

to slightly convex outward.

29:42

And because of the persistent impaction irritation,

29:48

friction, it develops a small cyst right here,

29:50

which in 1990 in the American Journal of Radiology,

29:53

they described as a herniation pit

29:56

and they said, asymptomatic, not an intraosseous ganglion,

30:01

uh, of no clinical significance.

30:03

Well, it turns out all three of those things are wrong.

30:05

So don't believe everything you read it is symptomatic.

30:09

Uh, it is a part of impingement syndrome

30:12

and it is an intraosseous ganglion,

30:14

and it likes to occur right here at the

30:17

a spherical head neck junction.

30:19

I mean, look at the tapering in the back

30:21

and the lack of tapering in the front.

30:25

The position that these impingers least like is hip flexion.

30:29

Uh, they don't like it.

30:30

Inflection, abduction and external rotation.

30:32

The so-called favor position and they don't like it.

30:34

In the flexion abduction internal rotation position,

30:38

the so-called ER position.

30:41

Now, another condition that that has been overlooked for

30:47

decades is delayed presentation of DDH

30:52

or developmental dysplasia of the hip.

30:55

Now we all know developmental dysplasia as a condition

30:58

where the acetabular angle is, is abnormal,

31:01

and the ace tablum kind of goes straight up

31:04

and down, doesn't have much of a horizontal bent to it.

31:07

You may have an upturned acetabular rim, absence

31:10

of the ligament, terries pulic fat may be prominent,

31:13

the joint space may be widened,

31:15

and you may have some uncovering

31:17

or under coverage of the lateral femoral head.

31:20

Let's see what we mean. Let's look at this coronal T one

31:24

first depicted by the black arrow.

31:28

Well, if you really look at this hard,

31:31

the acetates right here, this patient made that spur,

31:37

they acquired that spur as a reaction to try

31:41

and maintain the coverage of the femoral head.

31:44

It hasn't worked out very well.

31:45

71-year-old man completely lost bone on bone.

31:49

The weight-bearing hylan cartilage, uh, has an an a fusion.

31:54

Uh, the ligament tear is a little bit fat and irregular.

31:57

There's even a peri foveal erosion

31:59

and spurs within the joint on the sagittal projection.

32:03

Look at the size, uh, of this, this erosion.

32:07

And there's also an erosion in the femoral head

32:10

that's penetrating with extensive osteo edema.

32:13

So this was somebody that was born

32:15

with a very vertical ace tablum.

32:17

It stopped right there. The patient was undercovered.

32:21

And for 71 years they lived this way.

32:23

And this is the sequela of DDH.

32:26

And the reason that's important is it can affect the,

32:29

the procedure and the management

32:30

and the prosthetic that is used

32:32

to do the hip repair or replacement.

32:37

Another sign of DDH

32:41

is asity.

32:44

Now, if you have enough broad as Felicity,

32:48

then you'll develop what's known as a pistol grip deformity.

32:51

And I have a, an example of one, uh,

32:53

I have a better one coming up in a minute.

32:55

This one is, is quite obvious that the femoral head,

32:58

neck junction, uh, this one is even better.

33:01

Uh, this is a, um, 20-year-old long distance runner

33:06

with pain on and off for years getting worse.

33:09

But look, there's no tapering at all. It's just a curve.

33:12

Linear, convex outward hip. Same thing over here.

33:17

Yes, there is a label tear,

33:18

although I'm not showing for that.

33:19

Yes, there's a lab tear on the contralateral side.

33:22

These are not sulci.

33:23

So he is already developed lab tears

33:25

and no, he, he didn't have rheumatoid arthritis.

33:28

The incorrect diagnosis that was made

33:30

because he had bilateral hip effusions,

33:33

it was all biomechanic.

33:35

And one of the treatments for severe felicity is

33:38

to do e femoral plasty.

33:40

Um, these are variably successful.

33:42

And I will say I think the success rate

33:45

rests heavily in the skill of the hands of the surgeon

33:49

and how much experience they've had.

33:50

But look at, look at how much resected bone they perform

33:54

in this procedure is another example of, uh, somebody with,

33:59

with DDH, the femoral head is a little bit too big that

34:03

that may not be easy to appreciate.

34:06

There is a little degenerative tear posteriorly,

34:08

I'm not particularly concerned about it,

34:10

but look at the anterior outline of the femur.

34:13

It's kind of straight little bit convex outward.

34:16

Then it has another bump to it over here,

34:18

which shouldn't be there.

34:19

And it also has a cyst.

34:21

So bump cyst complex on this axial oblique

34:24

that was acquired off the coronal projection, showing you

34:27

that this patient's alpha angle is going to be rather large.

34:32

Uh, well over 60 degrees.

34:33

They have aspheric, they have a cyst,

34:36

and you can expect to find an anterior labral tear,

34:39

even though I'm not showing it.

34:40

And now I'm showing it. Here is a series

34:44

of radial views.

34:46

Now, why are they radial? Because the,

34:48

the shape of the neck is changing.

34:51

Uh, if it was a straight axial, you could,

34:53

you could follow it, you know, pretty clearly.

34:55

Um, but the,

34:57

the anatomic alterations are much greater

35:00

when you're going radial.

35:01

Uh, that being said, that'll be easy for you

35:04

because you'll get a scalp showing you that it's radial

35:06

and there is a tear, not very deep on another

35:09

of the radial sections.

35:11

Razor thin, but slightly deeper.

35:14

And then here it just looks amorphously irregular.

35:17

But that is abnormal. Make no mistake.

35:20

This, this is just from compression.

35:23

Uh, if you wanna use some civilian words, it's,

35:26

it's a mush pot, it's mashed,

35:29

and then it becomes a little more focal

35:31

and, uh, a lot more focal.

35:34

So it's there. I do not need an arthrogram

35:36

to make that, that diagnosis.

35:37

In a case like that, FAI two,

35:40

also known as pinch or impingement.

35:44

This time the cup is too deep.

35:47

The ace tablum overc the femoral head.

35:49

The neck is narrow, but it is the ace tablum that is

35:54

crushing the neck rather than the head neck junction

35:58

crushing the labrum much different.

36:01

And you, you see what happens here.

36:03

It's just a direct impact on, on the labrum.

36:06

And because this is low lying

36:08

and also very lateral, it starts

36:10

to push the femoral head backwards.

36:13

And that backwards compression yields

36:18

pressure related erosions in the posterior quadrant.

36:21

And eventually, as this process continues on and on

36:24

and on throughout age, all

36:26

of these erosions will meet in the middle,

36:28

and you will have one diffuse arthritic kip all the way

36:31

around with perhaps a big pressure erosion in the back,

36:35

a very long anterior acetabulum,

36:38

both inferiorly and laterally.

36:41

And you'll, you'll have a host of labral injuries,

36:44

including the posterior labrum.

36:46

So that, that's a very interesting biomechanical phenomena.

36:51

Now, it's not uncommon to have mixtures, uh, of the two.

36:54

And as you get more sophisticated,

36:55

you'll be able to sort those out.

36:57

There are some radiographic signs of pince or impingement.

37:02

Um, I think a probably three

37:04

of these you should probably know for your boards,

37:07

the crossover sign, Patrizio, ace, tabula,

37:10

and Cox of profunda.

37:12

And these, you should have learned in, uh, plain film

37:15

or radiography.

37:16

Um, protio ace tabula, uh, is perhaps the, the most noted

37:21

of them all associated with rheumatoid arthritis.

37:23

But it can be seen, uh, in, uh, this condition of pinch

37:27

or type impingement.

37:29

And this is nothing more than, uh, protruding

37:32

of the femoral head beyond the,

37:35

the medial acetabular, uh, line.

37:38

Um, here I've got coa profunda where the floor

37:40

of the acetabular fossa, the red line

37:43

overlaps the ileal issue line the posterior

37:45

column dash line.

37:47

So here your, your medial to the,

37:48

to the posterior column in Protio, the medial aspect

37:52

of the femoral head, which is the red line,

37:54

overlaps the ichi line.

37:57

And in the crossover sign, uh, also known as the figure

38:01

of eight sign, the superior aspect

38:03

of the anterior acetabular wall, solid green is lateral.

38:08

And as you come down, it swings medial

38:10

to the posterior acet tablum.

38:12

So they, so-called switch places.

38:14

Another thing I like to do is I like to look at the x-ray

38:18

and see in the middle, I,

38:19

I just put my eye in the middle of the femoral head.

38:22

And if I can draw a line with my eye,

38:24

which I always can from the superior acet tablum

38:27

to the inferior acetabular bone,

38:28

and that.is lateral to this line, I know that I have

38:34

a, a hip problem, a serious hip problem.

38:37

And the last one is the ischial spine sign

38:39

where the ischial spine is hypertrophy.

38:41

So let's take a look at, um, an example of pinch

38:45

or impingement On ct, we have the anterior wall,

38:48

the posterior wall, and the anterior wall is broken.

38:52

There's an ossicle, no, that is not an,

38:55

a developmental ace tabulary that is a fracture

39:00

and many of them are fractures have been

39:02

so misnamed over the years.

39:04

There are two types of pincer impingement.

39:08

Don't wanna get too technical with you,

39:10

but there's one where the posterior wall

39:12

is, is not very big.

39:14

It stays where it should right

39:16

behind the center of the femoral head.

39:18

And it's the anterior wall that does all the work.

39:22

All the, all the retroversion

39:24

that is produced on the femoral head comes from here.

39:28

Uh, this is very problem problematic.

39:30

And this is known as the retroversion type.

39:32

If both of them are projecting laterally, that is known

39:36

as the profunda type of FAI.

39:39

Let's look at another ossicle, uh,

39:41

that it looks like an osci tabulary

39:43

because it's very smooth in contour,

39:45

but it's a chronic longstanding fracture in somebody

39:49

that has FAI two.

39:51

Here's the profunda type of FAI two.

39:54

This time, not just the anter wall, which is broken,

39:59

it's fractured, not just the anter wall,

40:02

but the posterior wall is all, is equally

40:04

and perhaps a little bit longer.

40:07

Both of them go beyond the center of the femoral head,

40:11

both the anterior wall

40:13

and the posterior wall, so that it acts like the claw

40:16

of a crab grabbing the, the, um,

40:19

femoral head restricting motion, causing a lot of pain,

40:22

especially in squatting.

40:23

And you know, this one looks like the toenail

40:26

of a tyrannosaurus wreck or a crab claw.

40:29

Look at these crab claws with a broken fracture in front.

40:33

It looks a lot like the crab claw

40:35

that I have depicted in the color diagram on the left in

40:39

this entity of FAI two.

40:42

Now, the surgeon, the surgeon has a dilemma in this

40:45

situation, uh, of cam

40:48

and, uh, pincer acetabular impingement.

40:52

First, you know, are they doing a repair

40:55

or are they doing a replacement?

40:57

Uh, can they get away with e femoral acetabular plasty?

41:00

Is there another temporary maneuver like injection of civis?

41:04

Uh, what's the cartilage status?

41:07

What is the dominant impingement subtype?

41:10

How does the ipsilateral knee look?

41:11

In other words, they're gonna be able to walk on

41:13

that knee after a repair.

41:15

And how does the contralateral hip look?

41:18

So cam and pince are impingement.

41:21

Cam is undercovered by the acid tablet, pincer

41:24

covered shallow cup deep cup with a tapered neck,

41:29

broad neck, tapered neck pistol grip deformity,

41:32

acetabular inversion for FAI retroversion for FAI two

41:37

bump cyst complex for cam, not so for pincer,

41:41

there's no as ferocity.

41:42

There's a lot of, as Felicity in cam

41:44

alpha angle is elevated, alpha angle is

41:47

diminished in pincer impingement.

41:50

Either one of these can be secondary,

41:53

and one way you can get secondary

41:55

impingements is with spurs.

41:57

So keep that in mind.

41:58

It doesn't have to be a primary dysplastic, uh, abnormality

42:02

and pinch or impingement.

42:03

You can get impingement

42:04

by the anterior inferior iliac spine.

42:06

Overgrow, uh, this type cam is more common in men.

42:11

Uh, pin or impingement is more common in women,

42:14

but I do see it a lot in American baseball catchers

42:17

who are frequently men.

42:19

Um, this is a condition more commonly seen in people

42:23

around 30 who are athletic.

42:24

This condition seen in a slightly older age group.

42:28

Um, either, either one

42:30

of these positions can exacerbate FAI one and two,

42:33

but the classic position

42:35

for F fao one is the Faber position, flexion abduction

42:39

and internal rotation.

42:40

Squatting is the position for pincer type impingement.

42:45

The overwhelming amount

42:47

of pathology is in the anterior superior quadrant.

42:49

And FAI one in FAI two, it tends

42:52

to be more circumferential affecting the anterior

42:55

and the posterior labrum.

42:58

Let's turn our attention now to, um, apophysis.

43:03

Um, we've got the iliac crest,

43:05

the anterior superior iliac spine,

43:08

the anterior inferior IAC spine.

43:09

The greater trocanter, the less trocanter,

43:11

and the ischial tuberosity.

43:12

Those of you that are taking boards

43:15

or core examinations, these are, these are the physes

43:18

that you have to know and what comes off them,

43:20

which is listed for you here.

43:22

The, as i has as its origin,

43:27

the Sartorius and the tensor fascia Lata,

43:30

the A IIS takes off one head

43:35

of the, um, rectus femes, namely the direct head.

43:40

The indirect head comes off the acetabulum laterally.

43:45

The greater trocanter is the insertion site for a number

43:48

of structures, one of which produces a great deal

43:51

of trouble, especially in larger women.

43:54

And that is the gluteus medias attachment.

43:58

And then we've got the, the isum where we have

44:01

the attachment and origin of the hamstrings.

44:04

The biceps femes is a medial attaching structure.

44:08

And then of course, lateral on the, on the lateral side,

44:11

the semimembranosus is the attaching structure

44:15

and it courses medial.

44:17

So there's kind of a, a turn or a twist

44:19

or a spiral, thus making, uh,

44:22

these structures prone to hamstring injury.

44:25

Now let's talk about the, not the rec,

44:28

not the biceps femoris,

44:30

but the rectus femoral that's in front of the,

44:33

uh, in front of the hip.

44:35

The indirect head comes from the ace tablum

44:37

and becomes the central tendon.

44:39

The direct head comes from the A IIS

44:43

and forms the bulk of the muscle,

44:45

and then will acquire a fascial band

44:48

as you move more distally.

44:50

So let's take a look at a real simple one.

44:52

Lemme just grab a drink here.

44:57

You don't have to be too creative on this one.

44:58

Instead of tearing and avulsing

45:01

or affecting directly the muscle,

45:04

you have actually pulled off in an immature skeleton.

45:06

The A IIS separated from the ileum,

45:10

and there is the river

45:12

of separation here in the axial projection, once again, a,

45:17

a chism of separation between the bony vols,

45:22

A IIS and the base of the Ace Tablum.

45:25

Now, where is the indirect head?

45:27

There is the indirect head right there.

45:30

The, the direct head is attached to this.

45:32

So this is the direct head attached to the A IIS,

45:36

and this is the indirect head right there.

45:39

Here's the indirect head right there that will go on

45:42

to form the central tendon, uh, of this structure.

45:47

Let's move on to the A SIS, the anterior superior IAC spine.

45:51

There can be, uh, an avulsion at the level

45:54

of the apophysis as well.

45:55

Here's one that occurred right there along with, uh, some

46:00

of the structures that come off there.

46:02

This one came off with the fascia.

46:05

Uh, this one is associated with swelling of the fascia.

46:08

Lata and sartorius is another example of

46:13

a an A SIS problem.

46:16

At first glance, it looks like it's a pure

46:18

fascia detachment,

46:20

but then when you look over here, there is a piece of bone

46:22

with it, with the fascia lata.

46:25

So, uh, this is another example of an avulsion, this one

46:29

with bone, uh, taken the greater tuberosity in burin.

46:33

And I know we've only got a few more minutes.

46:35

Uh, these are the structures

46:37

that insert on the greater tuberosity.

46:38

I am not gonna ask you to memorize them,

46:40

but I have a nice mnemonic for it.

46:43

Po O2 G three.

46:45

And the one that I'm most interested in today is the gluteus

46:48

medias with second place going

46:51

with the gluteus minimus,

46:54

which inserts an laterally on the trocanter complex.

46:58

The gluteus medias has a broad anterior

47:01

to posterior insertion with a big fat tendon in the back,

47:04

uh, inserting on the greater tuberosity.

47:08

So here's our glute mead with its footprint,

47:11

which has a fairly long extension.

47:13

This is only part of the footprint.

47:15

Uh, it, it's about one

47:16

and a half centimeters from the proximal greater tube

47:19

to the mid greater tube.

47:21

And it is associated with several bursa

47:24

that we'll talk about in a minute.

47:26

The glute meat is more anterior,

47:28

it's a little bit stubbier and shorter.

47:30

Here in the sagal projection,

47:32

we can see the glute min in the front and the mead.

47:36

We're just seeing the posterior bundle of the mead,

47:40

which hardly ever tears

47:41

and inserts on the posterior superior facet.

47:43

The greater tube porosity,

47:46

it also inserts on the lateral facet

47:48

of the greater tuberosity.

47:50

So two facets are, are where the glute mead inserts.

47:54

There is a bald spot, uh, above the greater tuberosity

47:57

that I'll show you in a minute

47:58

that is associated with a bursa.

48:00

And most patients will have a little bit of signal on a stir

48:05

or on a c plus MRI between the glute meat

48:07

and the iliotibial band.

48:09

And I'll show that to you too.

48:10

And that's simply for lubrication of structures moving back

48:15

and forth between one another.

48:17

Here's our glute meat.

48:18

Here's a great look at our entire footprint

48:21

of the glute meat from proximal to distal.

48:23

Here is our bald spot,

48:25

and that little slit is the collapsed bursa

48:28

that sits in a fat pad, just, uh, medial

48:32

to the, to the glute meat.

48:35

And here is that little lubricated area called lubricant

48:39

that sits between the fascia, lata and the gluteus medias.

48:42

That's totally, totally normal.

48:45

Here are the facets of the greater, uh, trocanter.

48:48

Here's the anterior facet for the glute min.

48:51

Here's the lateral and posterior facet,

48:53

or posterior superior facet for the glute, uh, mead.

48:57

And looking from the back to the front

49:00

here is the posterior facet, uh,

49:03

the bursa associated with the glute max.

49:06

So here is the, the glute, uh, min and meat together.

49:11

Now, how would I know that? I wouldn't from one coronal

49:13

slice, but I am very far forward.

49:15

So I'd be very suspicious

49:17

that the minimus was involved in this tear

49:20

that has come off the greater tuberosity.

49:22

But I go to the sagittal and now it becomes quite easy.

49:26

The large, thick, strong posterior tendonous bundle

49:31

of the glute mead.

49:32

This is posterior, this is anterior is still on.

49:35

Then as we get into the middle of the glute me,

49:37

there's a defect again,

49:39

the anterior glute mead, there's a defect.

49:42

We get into the glute min right here.

49:44

You gotta know the anatomy. Glute min right here,

49:46

there's a tear, there's eruption.

49:48

So min tear me, tear me tear sparing

49:52

of the most posterior aspect of the mead,

49:54

which is usually the case.

49:56

Um, here's kind of a free arthrogram.

49:58

Uh, lots of inflammation to highlight, you know,

50:01

some abnormalities because we have

50:04

Hydroxyapatite Dihydrate deposition creating

50:07

massive inflammation.

50:08

There it is. There it is. There it is.

50:11

What did I wanna show you?

50:13

Well, I wanted to show you the glued mead,

50:15

and it is stopping right there at least this fiber of it.

50:18

So there, there are tears present.

50:20

There's massive inflammation.

50:21

But also look at the trocanter. It's a series of ski moguls.

50:26

We're up. We're in the, we're down, we're up, we're down,

50:29

we're up, we're down again.

50:31

We're up, we're down again. This is terrible.

50:33

How in the world is a tendon to slide back and forth

50:38

or inside and outside when you internally

50:40

and externally rotate over this roughen structure?

50:43

So it's a real problem That is a sign on an X-ray.

50:47

When you're looking at an X-ray

50:49

and you see that in somebody with hip pain,

50:50

you should be truly worried about the abductor complex.

50:54

Now, in the interest of time, I'm not gonna take you

50:57

through the Doha classification of groin pain,

51:00

but I do wanna remind you that hip pain

51:03

and labral pathology often presents in the groin.

51:08

So just 'cause it's in the groin doesn't mean it's

51:10

a groin abnormality.

51:12

Hip pain does radiate into the groin,

51:14

and you can peruse this list

51:18

of potential causes of groin pain, uh,

51:21

as you get a little more sophisticated

51:23

and comfortable with MRI.

51:24

But I do wanna talk about the IA sous

51:26

as a cause of groin pain.

51:28

It is formed by the iliac and SOAs major,

51:32

and it is a flexor and external rotator.

51:35

It's a, it can be a split tendon as a variant.

51:37

Uh, it is involved in kicking sports.

51:40

So professional football kickers get

51:43

strains of this structure.

51:44

It may aul in the juvenile

51:46

and most importantly, it's associated

51:48

with the ileus snapping hip syndrome

51:53

At the ileoanal eminence, this condition is known as

51:57

Cox salt hands.

51:58

There's an anterior type over the IOP tenal eminence.

52:03

You can also get this in total hip replacement over the A

52:06

IIS or you can get it posteriorly over the, um,

52:12

ischial tuberosity from the biceps.

52:13

This one's pretty rare. There's a lateral external type,

52:18

and this is an ileal iliotibial band

52:20

or glute max abnormality riding over an irregular

52:24

hypertrophy, greater tuberosity or greater troian

52:27

or inflection and internal rotation.

52:29

Let's see some examples to, to diagnose this.

52:33

First of all, I like ultrasound with dynamic internal

52:35

and external rotation if I'm gonna treat it.

52:38

But to diagnose it, I really like MR the best

52:41

because it's often a subtle finding

52:43

of nothing more than edema swelling

52:46

around the central tendon of the ileo sous

52:50

in the ilio sous muscle just like that with an axial,

52:55

highly perfected water, emphasized fat suppression image.

52:59

That is what it looks like.

53:01

Now, an ultrasound, you may inject that with steroids and,

53:04

and there are some other, uh, interventional, uh,

53:08

minimalist techniques that can occur.

53:10

And sometimes we even have to go in surgically.

53:13

Now the ilio o is bursal that that is not a person that is

53:19

musculo tendons swelling from persistent rough internal

53:24

and external rotation with those structures abutting, uh,

53:28

the anterior aspect of the femoral head

53:30

and the ileoanal eminence not shown

53:34

the ilio OAS PERA only connects

53:36

to the joint 15% of the time.

53:38

The operator external hispera only 5% of the of the time,

53:42

and the tro enteric person does not connect.

53:46

So when you have tro enteric bursal fluid,

53:48

lateral facet posterosuperior, facet anter facet,

53:52

that is not from the joint, that is from something external.

53:57

Let's take a look at this professional retired athlete

54:00

who played a running back for the Pittsburgh Steelers.

54:03

He's complaining of, yes, you guessed it.

54:06

Groin pain but snapping when he internally

54:09

and externally rotates in the gym.

54:11

And he is a gym rat.

54:13

So looking Corona, he's got this very large

54:15

fluid collection.

54:17

Now this time it is not a myotendinous area of injury.

54:22

It is a bursitis

54:23

that he has developed a long one, a wide one.

54:27

It's got some depth to it as well.

54:30

He's 52 years old at the time.

54:33

This was injected with sclerosing agents after aspiration,

54:36

and believe it or not, it went away.

54:38

That got taken care of in Pittsburgh,

54:40

even though he lives in Cincinnati.

54:42

But it was a successful, uh, outcome.

54:44

But that was another manifestation

54:47

of snapping hip hip syndrome.

54:48

The third type is intraarticular,

54:51

where you get snapping from a torn leg, terries,

54:54

loose bodies and joint instability.

54:55

And here's an example of one.

54:57

Some bodies ant medial producing both groin pain

55:01

and snapping on internal

55:03

and external rotation is also one inside the joint.

55:06

So our last area to cover in five minutes or less,

55:09

and probably one of the most important is joint replacement.

55:13

There are a number of soft tissue reactions

55:15

that can occur histologically,

55:17

and they, uh, they include

55:20

aseptic lymphovascular associated lesion,

55:23

which is basically an inflammatory monocytic

55:26

and lymphocytic response.

55:29

Then you can have metal that produces a synovial response,

55:34

and this is known as metalosis.

55:36

You can also have particulates that that come from a

55:42

non-metal on metal, um, device.

55:46

And that that friction can produce small particulates in the

55:49

joint and that can lead

55:50

to synovial overgrowth in a very bizarre fashion known

55:53

as pseudotumor.

55:56

And this is known as wear induced, uh, synovitis.

56:00

It's usually with either bone or metal.

56:04

Um, approximating a polyurethane lining is what does that,

56:08

whereas metalosis is metal on metal.

56:10

Let's look at metal on metal.

56:12

In this 59-year-old we have a T one,

56:15

which shows susceptibility effect

56:16

and aspect ratio distortion.

56:18

There's something over here, these little granular things.

56:22

But when you perform a sequence

56:24

that is very metal sensitive, like a gradient echo,

56:28

now those areas, they're, they're not simply small nubbins

56:32

of intermediate signal.

56:34

They bloom, they get bigger,

56:36

they get blacker, but they have shape to them.

56:38

There's one here, here's one here.

56:40

This is what metalosis looks like.

56:42

And you can, you can draw a nickel and cobalt

56:45

and chromium levels to try

56:47

and, uh, sure up your, your diagnosis.

56:50

Here's another example of melos.

56:53

A terrible looking large pseudo tumorous effusion

56:56

that is infiltrating the surrounding tissues.

56:59

You know, perhaps making you very concerned about, um,

57:03

particular disease.

57:04

And many of these histologies can coexist,

57:08

but this patient also has metal.

57:10

If you look down low,

57:12

there is a markedly hypo intense structure.

57:14

There's another one that's quite large

57:15

markedly hypo intense.

57:17

You have to make sure you're not looking at heterotopic

57:20

bone, which you weren't.

57:21

And how can you tell that?

57:23

You go from the T one weighted image

57:25

to the gradient echo image

57:26

and you see these objects appear artificially bigger than

57:30

they really are because they're made out of metal.

57:33

And that's what happens on the gradient echo sequence.

57:36

The particular reaction where polyethylene debris

57:39

or polymeric debris, uh, occurs

57:42

because metal on polyurethane

57:45

or ceramic on polyurethane creates a bizarre synovitis

57:49

that is much more easily diagnosed

57:52

with specificity on MR than ct.

57:55

Now when you do a hip replacement, the tissues

57:58

around the hip become fibrous.

58:00

So you develop a fibrous pseudo capsule

58:03

and that should be very tight.

58:05

So you should not be getting these floppy,

58:07

irregular areas of fluid.

58:10

Now, no, this is not an abscess.

58:12

You've got these very bizarre random areas

58:16

of synovitis, but no edema.

58:19

What kind of abscess is this big

58:20

with no surrounding per lesional edema.

58:23

So that should be a dead giveaway that you are not dealing

58:26

with, uh, an infectious process.

58:29

Here is, uh, another example of, um,

58:33

particulate disease, bizarre synovitis.

58:36

And these pseudo tumors have no respect for the anatomy.

58:40

They go wherever they want, they go into the groin,

58:43

they dissect into the abductors.

58:46

The amount of synovitis is variable here.

58:48

It's pretty large here. It's massively large here.

58:51

It is even more massively large in the groin with the bulk

58:56

of the process being synovium.

58:58

So as I said, bizarre pseudotumor synovial proliferation.

59:03

And this one also had, uh, histologically on, on a redo,

59:09

uh, acute lymphocytic, uh, vascular abnormalities,

59:13

also known as al valve where lymphocytes

59:16

and monocytes had had infiltrated the joint.

59:18

What else goes wrong? Periprosthetic fractures,

59:21

loosening joint instability, hardware failure,

59:24

osteolysis tendinopathy, glute me tears,

59:27

heterotopic ossification neuropathy.

59:29

That's your laundry list

59:31

for looking at every single postoperative hip.

59:34

Here's an example of a postoperative hip this time

59:37

with a fracture and an unsuspected fracture.

59:41

Look at the greater tuberosity.

59:43

It doesn't normally look like that

59:45

with a serrated blunted edge.

59:47

Where did it go now? It displaced right here.

59:49

It got pulled off. So now you gotta go looking for

59:52

that structure that is not heterotopic bone,

59:55

although, you know, your first reaction would be yes, it is.

59:59

But once you see the deformity of the greater tuberosity,

60:02

you make the correct diagnosis.

60:04

Now this is heterotopic bone.

60:06

Heterotopic bone is big, it's bizarre, it's irregular

60:09

and it has no shape.

60:11

You know, it has what I call novel shape, shape

60:13

that defies description stem loosening.

60:16

I think the last thing I'll show you, um, hard

60:19

to diagnose on Mr

60:20

because most patients are gonna have some edema in the shaft

60:24

of the femur from the femoral shaft being plumbed in

60:29

preparation to to place the stem into it.

60:31

But if that edema is isolated down around the stem

60:35

and there's associated thigh pain, then

60:37

that is very strong evidence you're dealing with a,

60:41

a loose distal stem.

60:43

But that's why three-phase bone scan is the favored

60:46

examination to make this diagnosis.

60:48

And here in all three phases, only one phase shown the

60:53

circumferential magnesium 99 MDP uptake

60:56

of the bone scan at the distal aspect of the prosthesis.

61:00

So I have taken you through some anatomy, some variants.

61:05

We have focused very heavily on the acetabular labrum on the

61:08

two types of impingement cam impingement

61:11

where there is a shallow cup

61:14

and a broad neck perhaps with a bump cyst complex

61:17

and pincher impingement where you have a narrow neck

61:21

with circumferential disease that evolves over time

61:25

and a crab claw deformity of the ace tablum.

61:28

And then finally we finish

61:29

with a flourish talking about the complications

61:32

of total hip replacement.

61:34

With that, I will take any questions that you have either

61:38

by chat or otherwise.

61:43

Thank you so much for your lecture, Dr. Pomerance.

61:45

Yes, if you've got questions, please throw those into the q

61:48

and a box or the chat.

61:51

Um, Dr.

61:52

Pomerance, I can read those out to you if you prefer.

61:55

I think that would be easier.

61:56

Awesome. What protocol

61:59

or sequences do you, do you do for hips?

62:03

Sure. So first of all,

62:05

every MSKK should have at least one T two for dating.

62:09

Uh, and I don't mean cupid.com, I mean dating acute,

62:13

subacute and chronic, uh, or remote for dating purposes.

62:18

Um, and, and to improve the visualization of anatomy

62:21

of soft tissue structures when there's

62:23

a tremendous amount of swelling.

62:24

You cannot do. You, you cannot do an extremity, uh,

62:29

joint evaluation without a excellent fat suppression proton

62:32

density image, which means your, your TE should be around 45

62:36

to 55 and your TR should be long

62:39

and you should have, uh, you know,

62:41

good quality fat suppression, spare spur special.

62:45

Um, if you have low field stir does a wonderful job

62:48

in, in that scenario.

62:50

And then finally, you should have a true T one

62:53

and my friends in OZ in Australia, they, they use a lot

62:56

of proton density with, uh, without fat suppression

63:00

to look at things like labra and menisci.

63:03

I, I don't like that as a tool.

63:05

Uh, there's much better tools.

63:07

They, they use it, I think

63:08

because the signal to noise is so good.

63:10

But what it does is it, it hides inflammatory reactions.

63:14

It, it also hides pathology in the bone, serious pathology.

63:19

So I prefer to use a true T one.

63:21

And then in terms of projections, uh, I like

63:24

to have a contiguous axial T one, an angled axial

63:28

with the long axis, uh, of the hip, especially

63:30

with proton density, uh, fat suppression.

63:34

I like to have a straight sagittal

63:36

to look at the glute mead.

63:38

And for that, I'll either use a proton density,

63:40

fat suppression or a T two.

63:43

Uh, I like the proton density,

63:44

fat suppression a little bit better.

63:46

And then I will have a series of radis

63:49

that can either be gradient echoes, uh,

63:52

or 3D gradient echoes that, uh,

63:55

that go from the posterior superior

63:57

to the anterior superior quadrant.

63:59

Awesome. Thanks. Sure.

64:01

Would you consider Mr arthrogram routinely

64:03

for labral chondral injuries?

64:07

I do not consider, I, I considers the wrong word perhaps

64:11

to answer with, I do not use arthrography

64:14

to diagnose labral, uh, or chondral abnormalities.

64:18

I use small field of view, high resolution,

64:20

heavily water weighted MRI in concert with T one,

64:24

small field of view, unilateral MRI, to look at, uh,

64:29

subcortical erosions.

64:32

Um, I, I do bring patients back for arthrography.

64:36

Uh, if I have a, a serious history, a strong history,

64:41

and I have not found the abnormality,

64:43

but as time has gone on

64:44

and we've gotten better at our craft at, at our trade, um,

64:50

this has come up maybe one in 250

64:53

cases, not commonly at all.

64:54

So it's much easier to bring them back,

64:57

which is a rare event than it is to do that for every case.

65:00

Now I know a lot of serious

65:02

sports medicine people like that.

65:04

Um, but I will say there are some major disadvantages,

65:08

especially doing it without pre contrast.

65:10

MRI, just doing the arthrogram, you're going to hide all

65:13

of the inflammatory reactions

65:15

that steer you towards the pathology.

65:17

That's important, relevant, and active.

65:21

Great. All right. Let's do one more,

65:23

and I'll grab it from the chat here.

65:26

How do you differentiate between transient osteoporosis

65:29

of the hip and early A VN?

65:32

That's a great question. And, um, it's one

65:34

that comes up frequently.

65:37

So in early av n you know, you'll, you'll go, you're going

65:39

to get osteo edema,

65:40

and you're going to get transient osteo edema of the hip.

65:44

Uh, you're going to get osteo edema of the hip.

65:45

In T-O-H-T-O-H has a characteristic demographic.

65:49

It was described in pregnant women,

65:52

but it occurs in my experience, between six to one

65:56

and nine to one frequency in men.

65:58

So first male gender.

66:00

Secondly, no trauma in TOH.

66:04

Third no risk factors.

66:06

In TOH, you, you draw a, a sed rate, uh,

66:10

you draw a calcium, you draw a phosphorus.

66:13

And by definition, all of those things must be normal.

66:17

In, in TOH, in TOH it's not uncommon

66:22

to see osteo edema in the femoral head and holo edema.

66:26

Whereas an av n it's usually segmental in

66:29

a vascular territory.

66:30

So holo hip edema,

66:33

and then skip areas into the acetabulum.

66:36

Very common in TOH very uncommon in, um,

66:41

in avascular necrosis.

66:43

In avascular necrosis.

66:44

You know, you're gonna, you're gonna

66:46

search for risk factors.

66:47

You're gonna search for marrow, poly may,

66:49

you know, maybe they're on steroids.

66:51

They, they don't necessarily have marrow power in, in TOH.

66:55

And you'll, you'll probe for some

66:56

of the other risk factors like, you know, scuba diving

67:00

and, um, and,

67:01

and patients with SLE, uh,

67:04

of course prednisone administration

67:05

or even, uh, Cushing's disease would be a risk factor

67:08

for avascular necrosis.

67:10

And then finally, in, in avascular necrosis,

67:13

you're gonna have that subcortical infraction that parallels

67:18

the, the arc of the, the cortex, the fractures

67:22

that occur in TOH, whether they are the cause

67:26

or the effect nobody really knows are very random y yeah,

67:31

they'll be in the head, but they won't be in a perfect arc.

67:33

They'll be here, there and everywhere in any direction.

67:36

So hopefully that helps you.

67:38

Uh, one other thing in TOH early on you get effusions

67:42

and av n early on you do not get effusions.

67:45

So hopefully that'll help you differentiate the,

67:49

Thank you so much for answering those questions.

67:51

And thank you so much for your lecture

67:53

and for going over time, Dr.

67:55

Pomerance. We so appreciate it.

67:56

Yeah, my apology for going a little bit over,

67:59

but, uh, everybody have a great day.

68:00

Awesome. Thank you so much.

68:02

And thank you everyone else for participating in our Noom

68:04

conference and asking such great questions.

68:06

Today, you can access the recording of today's conference

68:09

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68:13

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68:16

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68:18

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68:21

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68:25

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68:28

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68:30

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68:32

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68:34

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