Posterior Capsule Disruption
HIDEInteractive Transcript
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Case is a 15-year-old, uh, soccer player
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with left knee injury four days prior.
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So going from medial to lateral.
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Again, the,
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there's all this edema in the medial supporting structures
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as we correlate.
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You can actually see the MCL is intact,
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but the posterior oblique ligament,
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this triangular structure, there's a lot of edema.
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So as you go posterior on this coronal sequence, you can see
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that the posterior oblique ligament, um,
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is detached from the, uh, from the femur.
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So there, it's torn there.
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As we scroll laterally, you can see that
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there's, uh, this, this, uh,
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signal within the semimembranosus.
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And, uh, as Dr.
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Resnick had mentioned, um, when you, when you get injury
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to the semimembranosus,
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and this is primarily the direct head,
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but this is, um, some partial tearing,
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intrasubstance tearing, then we're not surprised, um,
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that there's gonna be an ACL, uh, injury.
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And here the, uh, the ramp, um, area, this meniscul,
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uh, capsular, meniscal tibial ligament is also torn.
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So there's a ramp lesion.
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And notice that as we're getting, I mean, there's, there's,
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um, tearing of some of these gastrocs,
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but the posterior capsule is completely disrupted here.
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And we see that the PCL, um, has this high grade tearing.
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If I triangulate, the PCL should have, um,
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a nice footprint, uh, it, it on, on the, um, axial images.
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I usually think of it as going at least from 12 to, to this,
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uh, like nine o'clock or,
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or three o'clock position, depending on the, the knee.
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But, uh, much of this footprint is, um, it, it is torn.
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And so this is a high grade PCL tear,
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certainly greater than 50%.
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The ACL we is completely torn.
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And as we get to the, uh, lateral compartment, you can see
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that the, uh, there's a partial tearing
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of this posterior root, of the lateral meniscus.
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And he had the wrist berg ligament that was torn here.
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And Humphrey doesn't look so bad.
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And the popal meniscal fascial are also torn.
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Pretty much all of them.
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And the poster lateral corner was,
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uh, basically taken off of the fibula here, complete tear.
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And so you can see that from, from it.
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It's not difficult to imagine
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that this is a hyperextension mechanism.
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Uh, and so you, you basically tore the posterior capsule.
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You tore the posterior oblique.
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And, and, uh, we, we have extensive, uh,
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extensive injury
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At, uh, arthroscopy.
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This was the empty wall.
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And so after, uh, debridement, um, of, of some of this area,
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you could see that there's a high grade PCL tear here.
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Um, on at the lateral femoral tibial compartment,
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there was a drive-through sign.
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Uh, so that just means that, uh, the supporting structures,
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uh, the ligament structures are torn.
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And there's this large gapping, um,
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in this lateral compartment
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and the popal meniscal fascial area
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and the capsule, all this was just torn.
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And they were able to, uh, uplift this lateral meniscus
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because of the, uh, uh, popal meniscal fascial tear.
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And, uh, this was all just, uh, floating through here.
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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