Meniscal Morphology
HIDEInteractive Transcript
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Now one of the important things
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that we wanna look at when we look at meniscal morphology is
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the width of the meniscus.
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And as we go ahead
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and look at the width of the meniscus on the medial side,
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I want to call your attention to the fat
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that the posterior horn is the widest part
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of the medial meniscus.
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So when we judge, in fact, utilizing sagittal images,
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a quick survey as to the integrity
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of the medial meniscus, you can see in fact
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that there is a wider posterior horn, then anterior horn.
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If the posterior horn is not so wide as the anterior horn,
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then prior meniscal surgery
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or meniscal pathology is likely present.
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Let's do the same experiment now on the lateral side,
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and if we do so, we can see
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that statistically it is the width of the body
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or mid portion of the lateral meniscus that is the greatest.
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So as a quick check on the integrity
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of the lateral meniscus, on the sagittal view,
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we should should see a posterior horn
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and an anterior horn that are of equal width.
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Now we're gonna talk about collagen,
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and I know this seems to be a complicated slide,
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but we have to go over the collagen architecture
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to understand the patterns of failure of the meniscus.
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This is a beautiful picture taken from the literature,
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so let's use that as our basis.
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There are two types
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of collagen bundles present within the meniscus.
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The first of these are longitudinal
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circumferential collagen bundles.
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I show them with this one yellow arrow here.
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These bundles extend along the circumference
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of the meniscus, connecting in fact the anter
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and posterior horns of the meniscus.
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And very important to accurate of peral.
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These collagen bundles occupy typically the peripheral
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50% of the meniscus
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and are not found in the inner portion of the meniscus.
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I'm gonna show you these in my drawing
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of transparent meniscus.
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Here you can see those red tubules.
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These are the longitudinal circumferential collagen bundles.
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The second type of collagen bundles are the radial
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tie collagen bundles.
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I show those with the orange arrow and arrow heads.
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These come in from the periphery all the way
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to the inner margin or tip of the meniscus.
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Here's what they look like,
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images taken from the literature.
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So what do they do?
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They connect the central
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and peripheral portions of the meniscus.
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Collagen is
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Key. You have
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to understand collagen to figure out
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what is going on with meniscal pathology.
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So let's summarize what we've said.
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Two types of collagen bundles in the outer half longitudinal
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circumferential collagen bundles.
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The red tubes in my drawing,
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connecting the anter posterior portions of the meniscus.
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The radial tie collagen bundles, which can go from the uh,
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periphery to the central portion, connecting, in fact,
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the central and peripheral areas of the meniscus.
Donald Resnick, MD
Professor Emeritus, Department of Radiology
University of California, San Diego
Mini N. Pathria, MD, FRCP(C)
Division Chief, Musculoskeletal Imaging
University of California San Diego
Eric Y. Chang, MD
Adjunct Professor, Radiology
University of California, San Diego
Brady K. Huang, MD
Clinical Professor of Radiology
UC San Diego Medical Center
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