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<v ->Well let's go ahead and look through these now

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one by one starting with the medial plica.

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And the medial plica is described as a,

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a film, or fibrous tissue that extends

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from the medial wall of the synovial membrane,

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you can see it here, it extends laterally,

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often parallel or almost parallel

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to the medial facet of the patella.

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Now it can extend for a variable length,

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sometimes it's only out in the periphery,

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sometimes it gets very far centrally,

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the more central it gets the more likely it may damage

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important chondral tissue as we will talk about.

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The medial plica is kind of

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the one that may connect with the others.

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Certainly if you follow it up superiorly,

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it may connect with the superior plica,

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and if you follow it inferiorly,

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it may in fact connect to the inferior plica.

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You can see by drawing top right what it looks like.

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You can see by arthroscopy on the bottom right,

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and on the Sagittal MR image you can see

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what the typical medial plica looks like,

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in that Sagittal plain.

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Now I want to call your attention again

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to an image I showed you previously

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to point out that you don't want to mistake

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the collapsed suprapatellar recess of the knee joint

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for a medial plica.

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This is a normal thin physiologic plica.

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This is not a plica, this is in fact the collapsed pouch

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with fat located both in front and behind it.

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Don't make the mistake of calling that upper image

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a thickened plica.

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Normal plica generally are one to two millimeters in width,

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there is some variation in that,

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but that's a general idea.

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Pathologic plica may be as little as three, two,

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or millimeters in width,

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but can be over a centimeter in width.

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The medial plica syndrome has been described

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with plica that are thickened,

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and particularly those that are long.

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There's some classic pictures that have looked at this.

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I included two from 1938 here.

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This is what a normal medial plica looks like,

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here's a pathologic plica.

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And I think if you look at that drawing

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and look at this image taken from a recent article,

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it looks almost identical.

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Here is that thickened pathologic medial plica,

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here is the damage going on in the patella,

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and in the trochlea.

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So, you can have damage to cartilage both in the patella

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and in the trochlea.

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The syndrome is particularly important in young people

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involved in sporting activities,

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including running, and jogging, and cycling,

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and other sports as well.

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And it can produce pain, tenderness,

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a snapping or locking sensation.

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The symptoms can be mistaken for a medial meniscal tear.

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Some people believe that the medial plica

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is one of the plica that can be associated

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with altered patellar tracking.

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On the top is a specimen of ours

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showing you in the white arrow, the thickened medial plica

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extending between the patella and femur,

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and showing with the black arrows,

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that the cartilage abnormalities on both

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the patella and trochlea.

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On the bottom is an example of what a slightly thickened

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but short medial plica would look like,

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extending from the medial side of the joint centrally,

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and I point to a chondral fissure.

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And by the way, we're gonna talk about

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fissuring of cartilage I think on Sunday.

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We'll get in to detail about that.

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But that's an example of what can be found

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and the typical location, if you add a,

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say where in the patella you see it,

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it's the junction of the medial patella facet

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and this which is called the odd facet,

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or most medial facet of the patella.

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So the patella has three facets.

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Odd facet, medial facet, this is a median ridge,

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and then the lateral patellar facet.

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This is the classic location right there.

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With all these plica, there are classification systems

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that have been described.

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I don't use them in my practice,

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I'm not sure many people do.

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The medial plica is divided into four types.

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A, B, C and D, depending upon the width of it,

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the thickness of it,

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and whether or not it has pedunculated tags

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associated with it.

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You can see the drawings indicating what those types are,

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and I'll just illustrate a couple of them.

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This would be a type A or type B thickened plica.

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Not too long, extending to the area

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of the medial patellar facet.

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Certainly thicker than the normal plica,

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and you see what it looks like in this Sagittal plane.

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And this one's slightly thickened,

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I don't remember if this patient was symptomatic but,

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it's showing you a longer plica,

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perhaps a type C medial plica,

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extending into the more central part of the joint.