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<v ->Now there are terms that we use

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when we do our MR imaging reports.

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And they're kinda interesting terms

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probably some of you use the term recess.

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Some of you use the term gutter.

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Whenever I'm using a term

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I like to go to the English dictionary

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and kinda look up the meaning of that term.

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And here are the English definitions

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not bad for recess for gutter.

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I'm not quite sure how that fits into anything

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we see on an MR examination, but we do use these terms.

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So you should be aware of some of the classic recesses,

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for example, of the knee joint.

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I've already commented on this one,

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this super tower recess

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here extending vertically upward above the patella.

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Often we'll see two recesses within Hoffa's fat pad.

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One is a vertical one that extends downward

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from the top of Hoffa's fat pad

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and another not shown here as a transverse one

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that extends lower down but more in a transverse direction.

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I've commented about the spaces

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that occur around the popliteus meniscal ligaments

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that we do have a sub popliteus recess

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located below the level of the lateral meniscus.

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Here's the popliteus tendon.

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And this goes downward as you know behind the tibia.

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And it's an important space

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as I'll show you when we talk about intraarticular bodies.

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The other word is really confusing

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and that's the word gutter.

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And I've heard many of our fellows

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put in a report that this thing is located in the gutter.

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Well, I can tell you that there's no clear definition

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of where, for example, the knee gutters are.

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And if you're telling an orthopedic surgeon

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or just look in the gutter,

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they've kind of gotta go around the periphery

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of the joint they're gutters everywhere.

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So I went into their literature

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and in fact although they described gutters

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in all different quadrants of the joint the classic,

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gutters to them are parafemoral gutters.

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And perhaps the one that is most important to them

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is a space shown here beneath the popliteus tendon

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between it and the lateral femoral condyle.

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This is what it would look like at the time of arthroscopy.

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This is a positive lateral gutter drive through sign

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where that space is markedly wide.

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That's why they wanna know about it

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And indeed that is usually indicative

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of a injury to the postal lateral corner of the knee.

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When we talk about parameniscal gutters,

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we do find things in there.

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And one of the things we find is a meniscal flap.

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Now I wanna again, English language, I just mention it.

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So fragment is something

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that is not connected to anything else.

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A flap is connected on one side to something else.

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This is not a meniscal fragment.

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You're looking at a meniscal flap, displaced downward.

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This is one of the characteristic locations

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often associated with erosion,

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sometimes edema of the tibial condyle and plateau

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and displacement of the medial femoral condyle.

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So here is a parameniscal gutter

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where a meniscal flap resides.

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Here's an another one.

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I have a lot of these, so I they're pretty images.

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So here's a second one.

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And here's another one, right?

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Showing you this is intra-meniscal ganglion

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says more about that in a moment

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displacement down into the medial parameniscal gutter.

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Now, one of the interesting articles

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that that I found not too long ago

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just a couple years ago,

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looked at the location of intraarticular bodies

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in the knee joint.

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And it's important for you to to know this

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because you know, it's not always easy, right,

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MR to find bodies unless you have a large effusion,

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CT is much better.

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I think brain films can be much better.

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But statistically if you try to figure out

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where the bodies are.

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Okay, where they are, there are two locations

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which are most common.

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That what's called the PCL recess.

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And this is what that looks like.

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So I immediately am gonna look in that area

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to find intraarticular bodies.

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And the other, the area we've already talked about

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is the subpopliteal recess of the joint.

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And so you always wanna look here

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and sometimes you're even lower than this.

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Those are the two most common sight

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of intraarticular bodies.

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Now we can use the same kind of analysis.

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Let's go to the glenohumeral joint.

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And if in fact, you do an arthrogram

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or in fact if the patient has a large effusion,

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there are three areas of the glenohumeral joint

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that are called recesses.

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A finger-like diverticular here

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beneath the subscapularis muscle and tendon

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the subscapular recess prominent,

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by the way with internal rotation of the joint

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a kind of dependent area here, sac-like an appearance

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the axle recess, and then a part of the synovium surrounding

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or almost surrounding the bicipital tendon sheath.

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That's the bicipital recess.

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And bodies often localize in one or more of those areas.

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So here's an example of severe glenohumeral joint OA.

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We're gonna be talking about OA in another lecture.

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Here are some bodies that are present

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within the subscapular recess.

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And by the way, on a radiograph,

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it may look like a large cartilage

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and its tumor of the scapula.

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Here's an example showing you bodies

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within the bicipital tendon sheath.

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I come back to the wrist, if I have a favorite joint,

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it is the wrist.

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And I became interested in this

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because I always wondered

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why rheumatoid arthritis produced early erosions

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of the ulnar thyroid.

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Well, I'm gonna tell you why actually right now.

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Here is a radial carpal arthogram.

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There are two recesses that occur

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that communicate with a radiocarpal joint.

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They're normal.

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This is known as a volar radial recess.

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It can be multiple.

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You can have more than one.

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Typically located away from the radial side of the radius,

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The reason that's important is

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when you're trying to figure out

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if you have a ganglion sheath beneath the radius,

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they tend to be a little bit more radial than these.

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These are normal volar radial recesses.

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But this is the one that I like.

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This is the prestyloid recess

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of the radio carpool compartment.

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Finger-like again, a diverticulum

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that kind of extends over toward the ulnar thyroid

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and baths the volar surface of the ulnar thyroid.

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Early synovitis within that particular recess

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produces the classic erosions on the under surface

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of the ulnar thyroid and rheumatoid arthritis.

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So therein lies my interest in this particular recess.

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So here's an example.

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You've seen the slides at the images at the top.

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You can see what this looks like.

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Here is that recess extending down, right,

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very, very nicely,

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prestyloid heading toward the ulnar thyroid.

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Here's what the erosion would look like.

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Here is what synovitis within the prestyloid recess

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would look like a lot of reactive marrow edema.

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And I can tell you

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this simulates one of the lesions

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that involves the triangular the fibrocartilage complex.

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So you may mistake this for traumatic disruption

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of the lamina of the TFCC

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when you're dealing really with synovitis

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in the prey recess of the radiocarpal compartment.

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We go down to the level of the ankle joint

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and there recesses everywhere.

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Medial, lateral, anterior, posterior

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and again, I have a favorite.

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My favorite is this, which is the syndesmotic recess.

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Typically it doesn't extend up more than a centimeter.

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Some people say that if it goes up more than a centimeter

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you got an injury of the syndesmotic ligaments, all right?

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I don't know if that's a great rule,

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but it's one that we consider.

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By the way, this was an ankle acumen

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20% time communicates with the posterior sub tailor joint.

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You can see it nicely in this particular person.

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But that syndesmotic recess

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is the tightest part of the ankle joint.

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So when you have a synovial process in the ankle joint,

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yes you can get erosions elsewhere.

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And the tail is immediately, laterally,

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anteriorly, posteriorly but the largest erosions

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often occur in the area of the syndesmotic recess,

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'cause it's tight there.

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This is an example

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of diffuse pigmented villonodular synovitis.

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We'll talk about its new name

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a little bit later in this course,

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but here is showing you the degree of erosion

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that can occur in opposing surfaces of the tibia and fibula.