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A 28-year-old woman with neck and right shoulder

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pain after an MVC, Motor Vehicle Vollision.

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Very interesting what's happened over the

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years with motor vehicle accidents,

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with the development of seatbelts,

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the type of injury that you expect has changed.

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Initially, we were unrestrained back in the 60s,

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then we got restrained by belts.

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And when that happened,

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when there's a car accident,

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people would reach up and grab that overhead

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strap that was in the car,

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and the arm would get jerked back.

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And when that happened,

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that would produce either a slap, lesion,

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and maybe even detachment of the subscapularis.

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That's much less common nowadays because

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now you have the shoulder strap.

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So with the shoulder strap, as you come forward,

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the humeral head may impact against the dashboard

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or against the airbag,

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and you may get some posterior subluxation

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or an anterior contusion. So,

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thinking about the mechanisms of injury,

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understanding what's going on psychosocially and

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socially really helps you when you're

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reading musculoskeletal MRI.

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So here are two quite gorgeous-looking images.

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This is a specific type of additive gradient

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echo on the left. So this is a gre,

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very articular surface-oriented.

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And on the right is a fat suppressed

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proton density image,

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the so-called detection sequence where the

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fat is really dark. For you beginners,

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this is where you look for bright spots.

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So let's scroll up and down.

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Here's your triangular rotator interval.

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Oh, that's a triangle.

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There's part of your triangle right there.

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Here's part of your triangle right here.

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And here's the anterior aspect of the interval

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formed by the coracohumeral ligament.

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This one's formed by the humerus.

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This one's formed by the glenoid and SGHL.

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And you've got yourself a beautiful rotator

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anterior interval triangle.

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If there's an anterior interval,

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there's got to be a posterior interval.

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And there's even a postero inferior interval.

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There's three intervals,

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and that can be a story for another day.

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The anterior interval is the most important

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of the three. So we're scrolling about.

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We're too about.

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We see a little bit of fluid right here

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in the bicep sheath. That's okay.

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Fluid likes to hang out there.

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It communicates with the joint space.

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There's trace fluid in the joint space

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a little more than our wrestler.

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So would I accept that as normal?

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I would say trace slightly increased.

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Again,

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I don't like to see fluid in

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a generalized fashion.

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I'll allow maybe one or two areas of less than

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a centimeter of fluid when I get down low.

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Just a little bit too much,

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but admittedly subjective.

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But what's this?

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That's not a place where fluid

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would normally accumulate.

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It's not dependent. Right. What's dependent?

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Axillary posterior.

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When you're lying on your back, but not up high.

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So what is that?

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So we're already assisted by that.

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Let's go to the sagittal.

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This is,

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we haven't given many props to the sagittal,

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and on the sagittal, we see something right here.

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Now you have to figure out what's anterior.

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What's posterior? Anterior coracoid.

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So that's posterior.

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I will give you the fact that there.

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Is some swelling of the AC joint.

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This patient is 28 years of age.

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Yeah, more than they should have.

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The AC joint is definitely swollen.

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Let's keep looking.

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It. Now,

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Somebody called this posterior glenoid dysplasia.

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I think the posterior glenoid

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Is cold stone normal.

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There's your tiny little notch

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Of Osaki right there.

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The tip of the capsule goes to the

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Point of the labrum in the back.

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The capsule goes medial to

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The labrum in the front.

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That's normal.

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There is no posterior glenoid dysplasia.

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The version of this shoulder,

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To answer one of your questions,

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Is normal right down the scapular spine.

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Perpendicular is the anterior glenoid cup

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To the posterior bony glenoid cup.

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It's a perfect 90 degree angle.

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There is no retroversion whatsoever in this case.

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Let's go to our coronal.

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Let's get

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Three different sequences. Okay.

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I've got a T1 on the right,

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Which is not that helpful for the rotator cuff.

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I find it very helpful, though,

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For bone and also to look for

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Adhesive capsulitis.

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Let's go to the coronal proton density

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Fat suppression image.

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Wow. Something's going on here.

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And here's the T2 weighted image,

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Not quite as sensitive.

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So we have a little bit of signal right there,

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And it continues very subtly right there,

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And it continues on interstitially.

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There it is. Oh, it was really well defined now,

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And you see how it's interstitial?

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It's concealed,

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Because if you come at it from the outside in,

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You've got those fibers over top of it.

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If you come at it from the under surface

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Arthroscopically, you go in from the frontier,

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You bring your scope up there,

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And you look underneath.

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All you see are these little,

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Thin gray fibers right there.

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So you can't see it.

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Arthroscopically it's a completely

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Concealed lesion.

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So there's a family of concealed lesions,

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Like the concealed interstitial delamination

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Tear at the footprint.

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Or you could get one that maybe wasn't concealed,

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That you could trace back to the articular

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Surface. Now here, you can't trace it,

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But let's scroll.

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There it is.

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Look at it here. Now let's go forward.

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There it is again. There it is again.

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Now, let's go backwards. Here it is.

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Here it is.

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And here it is. So this portion was concealed,

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This portion not.

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So if you went in with your scope and

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You were very carefully looking,

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You'd run into it on the under surface right here.

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So, in summary, then it isn't concealed.

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You can get to it from the humeral side of the

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Joint, from the articular side of the joint.

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And so this one is a paint lesion,

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A partial articular sided tear with

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Interstitial extension known as a.

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Paint lesion for partial articular sided

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Tear with interstitial extension.

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What are some of the epidems for tears?

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Well, if you just have an interstitial tear here,

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Which is on the humeral side of the joint where

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You can't really get to it because there's

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No articular surface here,

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That's called a concealed interstitial

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Delamination tear. So that one would be concealed.

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What if you took out the deep fibers of the cuff

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And you retracted them all the way like that?

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So the cuff would retract here

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Along its deep under surface?

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You'd call that a partial articulated

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Supraspinatus tear with avulsion or a pasta

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Lesion. If the upper fibers did that,

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You'd call that a reverse pasta lesion.

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These are just some of the epinems you're

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Going to encounter in the shoulder.

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But the main finding in this case was a partial

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Articular sided tear with interstitial extension.

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There's your interstitial extension.

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There's your articular sided involvement of

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Paint lesion. Now, one other comment.

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When you get past this juncture right here,

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You cannot get an arthroscope in here.

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This is attached to the humerus.

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There's no articular space here.

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So all tears that occur over here,

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Unless they come out the bursal surface,

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Are concealed.

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Tears here would be considered bare

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Area tears on the humerus.

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Bare area tears here would be considered

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Formal articular sided tears.

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And those continue on medially.

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So

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Concealed humeral sided, bare area,

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Articular sided right there and then articulated

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From there on more medial and just to color

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It properly, we have three zones here.

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We're going to say this is the concealed zone,

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The humeral zone.

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We're going to say this is going to be the

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Bare area zone, which is articular.

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Then we're going to take another color of blue and

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We're going to say this is also articular,

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But non bear area. What is the bare area?

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It's an area of the humeral head that

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Is articular but no cartilage.

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This was a tear originating from the bare area

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With interstitial extension, the paint lesion.

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In summary,

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Paint lesion normal. Glen White cup.

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One of you said that the posterior labrum was

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Hypertrophied. It's cold stone normal.

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It's a little bit smaller than the anterior

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Labrum, which it should be,

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And there is absolutely no glenoid dysplasia.