Interactive Transcript
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Now we have our most favored nation
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projection, the coronal projection with
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arthrographic contrast introduced into
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the joint to highlight the anatomy.
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Let's begin with the skeleton.
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The acetabulum, with its labrum, covers
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the femoral head right at its drop-off.
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That proper coverage is one of the first things
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I look at in assessing the coronal projection.
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If the acetabulum is too far medially, we
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say that the coverage is insufficient or
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undercovered and the patient most likely has a
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variation of developmental dysplasia of the hip.
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There is a measurement for this
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that we'll discuss at a later date.
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I also look at the tapering of the
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femoral head-neck junction to make
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sure that it's symmetric and that there
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are no acquired or congenital bumps.
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When there is symmetric tapering,
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this is known as sphericity.
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But when the neck is too broad or
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bumpy, it's known as asphericity.
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We have our transverse ligament, our
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inferior recess bounded by the capsule.
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Here's a small synovial fold or foveal fold.
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The capsule is filled with some contrast,
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and the ligamentum teres comes up
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and inserts on the fovea capitis in the
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region of the femur with its two heads.
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We've got hyaline cartilage, the collapsed
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joint space, the fluid isn't distending
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it in this location, and more hyaline
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cartilage with a crease in the acetabulum,
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which is a normal developmental fusion
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site for the triradiate cartilage.
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Out laterally, on our water-weighted
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image, we see the capsule with virtually
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no fluid in a young person, interposed
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between the capsule and iliofemoral
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ligament and the underlying acetabulum.
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But fluid may creep into this space
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as one gets a little bit older, and the
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capsule naturally becomes more pliable
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and strips a little bit away, and we may
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see 2 to 4 millimeters of fluid interposed
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between the labrum, the acetabulum, and
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the capsule, and that's okay, as long
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as there are no other secondary signs.
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We're able to depict the end of the capsule
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here and here, and draw a line between
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the two. For everything above that line is
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going to be intra-articular, as fractures.
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And everything below that line is
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going to be extra-articular, the intra-
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articular having a more grave prognosis.
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So, this is a basic introduction
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to our coronal projection.
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The muscular insertions and origins
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you can get out of a textbook.
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Obviously, the greater trochanter.
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A very busy place where the gluteus
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medius, and more anteriorly, the minimus
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insert, along with the external rotators.
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But that will be a story for another day.
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And finally, in conclusion,
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let's scroll our labrum.
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A beautiful, dark, thorn-like,
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homogeneous structure, tightly
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attached in the back to the acetabulum.
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Let's move to the front.
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Sorry, that is the front.
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Tightly attached in the front to the acetabulum.
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Let's move to the back.
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And there it is also,
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tightly attached to the acetabulum.
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In a young individual, I don't want
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to see any clefts that are more
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than 25 percent depth of the labrum.
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And here I have one.
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In the anteromedial to superior aspect of
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the acetabulum, I do have such a cleft.
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And that cleft, by the way, is a partial
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thickness labral tear in this young individual.
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So you've seen the good labrum, and
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you've seen the not-so-good labrum.
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And the rest of the anatomy is cold stone.
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Thank you.
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