Interactive Transcript
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Continuing on with our discussion on
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osteochondral lesions, it just would not be
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complete without talking about the most classic
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form of osteochondral lesion, which happens
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around the knee in the pediatric population.
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Most specifically, it happens at the lateral
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aspect of the medial femoral condyle.
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So, let's find the fibula; that's lateral.
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So we know this is the medial femoral condyle,
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and if you notice, this is at the lateral
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aspect of the medial femoral condyle.
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So, you know the term LAME, L-A-M-E, which
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stands for Lateral Aspect Medial; you
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know, E is for epicondyle, but medial condyle.
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So, this is where you have the most
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common location of an osteochondral
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lesion in the pediatric population.
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When we talk about osteochondral
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lesions, we have to characterize them.
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It's not just enough that
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we say that it's there.
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We have to talk about the size
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of the osteochondral lesion.
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So, you have to measure the osteochondral lesion.
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So, let's go ahead and do that.
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On the coronal view, if I go from here
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to here, it's about 2 centimeters.
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On the sagittal projection, if I go
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from here to here, it's also about 1.4 centimeters.
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4 centimeters.
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So we've given the sizes.
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Now we have to talk about its characteristics.
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This image on your left is a sagittal
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fat-suppressed fluid-sensitive sequence.
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We notice, I'm going to get rid of this line
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just so we can see things a little easier.
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You notice there's a rim of bright signal,
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a rim of low signal, and some
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more edema underneath that.
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We can also talk about the
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integrity of the cartilage.
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You know, there's a little bit of high
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signal on the undersurface of the cartilage.
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Okay.
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And this rim of signal here is not quite
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as bright as the fluid in the joint.
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So that also tells us about
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instability or stability.
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If we have fluid signal around this
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area of osteochondral lesion, that's
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as bright as the fluid in the joint.
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Okay.
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Then that indicates an unstable lesion.
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If it's just merely edematous
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like this, it's still stable.
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The thing to realize is, in the
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adolescent period,
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osteochondral lesions are a lot more
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resilient than in the adult population.
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In the adult population, a rim of edema
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alone would qualify it as an unstable lesion.
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But in the pediatric population, you
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really need fluid signal to be unstable.
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So this is not unstable.
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Right, by that criterion.
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We also look to see if there are any cystic
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changes around the osteochondral lesions.
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This one does not have any cystic changes.
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If an individual cyst is more than five
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millimeters, or there are multiple
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cysts, then that also means it's unstable.
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And finally, we look at the
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integrity of the cartilage.
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If the cartilage has rifts or tears
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in it, that indicates instability.
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So, looking at all those findings, I would say
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that this is a stable osteochondral lesion.
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They will go in and maybe fix it
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by drilling, or they may just rest
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the knee to see if it gets better.
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In the pediatric population, oftentimes
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you'll have areas of abnormal or what
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looks like abnormal fragmentation at the
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posterior aspect of the femoral condyle.
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And that should not be confused
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with an osteochondral lesion.
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First, those lesions occur on non
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weight-bearing surfaces, like over here.
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And second, there's no associated edema.
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So don't confuse something that happens
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back here with something that happens
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down here for an osteochondral lesion.
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And typically, these lesions here happen in
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a younger population, maybe 4, 5, 6, 7, or 8.
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This over here typically
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happens in an older population.
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