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Hi, this is Dr.

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John Carino, emergency radiography prep.

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This session is for a pelvis and hip.

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So with the pelvis,

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there are numerous radiographic projections, uh,

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that one can use to try diagnose, uh, trauma to that region.

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Typically we'll start with an posterior pelvis

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and if there's an affected side, the AP of the hip,

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there are 45 degree oblique views

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or projections known as the juda projections.

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Depending on the side that you're considering for injury.

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One side is considered the anterior opterator view

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and the other side would then be the posterior

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iliac wing view.

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There's a frog lateral that can be done to try

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to get an orthogonal projection

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and also a groin lateral, which is also sometimes known

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as a surgical lateral or Dans Miller view.

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Again, to get more of an orthogonal projection

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for spatial information.

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So with imaging the X-rays of the pelvis,

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we typically have a AP of the pelvis.

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You can also perform an inlet view to evaluate the SI joints

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and internal external rotation

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deformities that may be present.

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The outlet projection evaluates the vertical displacement

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of the SI joint and hemi pelvis flexion

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CT is often required.

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So we'll see many CT images kind of augmented

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or supplementing what we identify in the radiography

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because there's a lot

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of concomitant injuries that may occur.

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So let's talk about how the projections are acquired.

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So with the AP of the pelvis,

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the patient is typically supine.

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We prefer to have their toes touching if it's not too

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painful, if it's possible,

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because then that puts the hip joints into the best profile.

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And so this is our AP projection

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and we can see a number of structures here

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that we're gonna go into detail in the next few slides.

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So on the AP projection part of our checklist is

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to identify the following structures.

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So these are the arcuate lines of the sacrum.

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So they should remain intact

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and you should see them as contiguous lines

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'cause some fractures may disrupt those arcuate lines.

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Here are the opterator rings.

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So that's the ring structure between the superior

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and inferior pubic ramus.

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The SI joint or sacroiliac joint.

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So sacroiliac joint injuries

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or diastasis can be part of pelvic injuries.

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So identifying the width and also congruity

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and symmetry of those joints is part of the checklist.

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And then the pubic synthesis, which may be

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slightly separated or offset,

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but can also be involved in fractures

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that involve multiple parts of the pelvis

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and the iliac wing.

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And then since we have a part of the lower lumbar spine,

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we can identify the transverse process of L five,

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which can sometimes also be involved in these pelvic

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fractures because of its proximity.

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So that part of the checklist then transfers into many

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of the lines that we identify in the pelvis.

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So as mentioned, the arcuate line should be these contiguous

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areas that we identify.

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Again, part of it may depend on the slope of the sacrum,

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which varies from individual to individual.

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The ator ring is a good part of the checklist, identify

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that there's no displaced fragments into that area.

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Other lines that we're also going to get to is the teardrop.

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So here the green dotted lines show this area

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of the teardrop of the medial aspect of the hip,

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and then other portions of the pelvis.

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We have our ileoanal line shown in red here

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at the cephalad superior part.

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It's confluent with the ileal ischial line,

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which then goes into the posterior part of the pelvis.

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Here the hip has a anterior

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and posterior uh, lips as part of the acetabulum.

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So anterior is typically projected more medial shown in the

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blue dotted line here.

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The posterior lip is typically more lateral,

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so it's gonna be shown in the brown line projected here.

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And then when we have appropriate position with the

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toes together or feet internally rotate as much as possible,

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we then have this nice smooth line known

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as the Chenin arcuate line here

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that tells us the alignment is maintained.

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So variations on that AP projection can perform it

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as a pelvis inlet view where the tube has angulation

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as shown in the diagram here.

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And this helps to assess internal external rotation

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of the hemi pelvis, opens up a portion

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of the SI joints in many individuals so that we can evaluate

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for sacral impaction and AP displacement.

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So here's an example of inlet projection,

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and this is part of the checklist.

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So we can identify the anterior aspect

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or anterior cortex of the sacrum, the pubic synthesis,

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and then the bilateral SI joints.

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Now the tube can be angulated the other direction

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as shown in the picture here

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where we can generate a pelvis outlet view.

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And so on this projection,

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we can put the sacrum more in phos

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and here can help identify sacral fractures.

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Again, looking for SI joints, syntheses is shia,

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and also potential flexion extension deformities

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in unstable fractures.

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So here's an example of an outlet projection.

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And so we can now see the arcuate lines in a somewhat

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slightly different configuration in ap,

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but still maintained with the thin white line of continuity.

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Our operator rings are opened up a bit,

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and then again, the SI joints should be fairly symmetric in

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terms of their width and congruity.

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And here's our pubic synthesis iliac wing.

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'cause again, you may have fractures

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that either involve a portion of iliac wing

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or sometimes isolated to that structure.

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Another view that's used particularly

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for SI joints is a uh, Ferguson,

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which again is angled similar to that previous projection.

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But here the angulation can be somewhere between 30

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to 35 degrees in the typical Ferguson

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or closer to 25 to 30 degrees for a modified Ferguson.

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While this is not typically used for trauma, it's more

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for looking at the SI joints, perhaps in the context

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of things like sacroiliitis.

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Now, in addition to variations of the AP projection,

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what is often acquired is

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oblique projections known as the juda views.

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So with our juda views, we can consider one side to be the

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internal oblique or operator oblique,

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where you have a 45 degree oblique affected side up.

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And then compared to that is the external oblique

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or what's known as the iliac oblique view,

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where you have 45 degree oblique of the affected side down.

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And this provides complimentary images of each side.

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So with the juda projections, it can be done

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with a wedge placed underneath the patient

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or sometimes by angulating the tube.

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And here's an example of the opposite.

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So with our typical juda views, one side

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as shown here on the left can be considered

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as the ator view.

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Whereas if we're focused on the right side in this jua

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projection, we can see the ator ring on the right side,

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the ichi line posterior wall,

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and then also the ischial tuberosity

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In the center is our frontal projection where again,

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we have the anterior

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and posterior walls of the acetabulum.

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So we have our ichi and then ileal pectineal line here.

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So as we go from our frontal projection to our

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iliac wing view, we can see that in this projection,

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the iliac wing is best visualized

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because it's displayed on phos.

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So other specialized views may be the flamingo view.

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This is where you put the person on one foot

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and take a frontal projection

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and then have them load bearing on the contralateral foot.

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And of course, it depends on the patient's condition,

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not in the acute setting,

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but more for chronic pelvic ring instability.

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And then you measure if there's a shift in the vertical

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translation of the pubic bones.

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And it's for identifying whether there's pathologic

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motion at the SI joint.

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Now, what's nice about the proximal femur

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and hip is that it helps us

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to understand the load bearing areas

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or gives us insight into wolf's law, which is the

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reinforcement of the trabecula along the lines of force.

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So shown here in this computer generated image,

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we see the orientation of the load-bearing trabecula

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of the proximal femur,

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including the vertically oriented primary compressive

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trabecula, which are denoted in the red lines,

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the black lines, which are the more horizontally oriented

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primary tensile trabecula.

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And then the yellow lines,

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which are the obliquely oriented

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secondary compressive trabecula.

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And then the intervening trabecular bone between

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that medially, converging compressive trabecula is known

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as war triangle, and it's a site of relative weakness.

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So that's shown as a yellow triangle

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where you have less load bearing.

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So now if we take that information

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and look at a AP projection of the dedicated hip

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as shown previously, we can see the

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reinforced trabecula along here.

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But with a dedicated hip projection,

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we have several lines we want to consider

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as shown in the diagram on the right.

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So if we look at A, that's our ileoanal line

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that we identified also in the pelvis.

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B is that ileal issue line more posterior part

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of the acetabulum.

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And pelvis B becomes nearly confluent with C,

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which is our teardrop, and is nicely shown here.

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The line of the teardrop is right next to the ichi line.

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And again, because of its shape,

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it's been likened to a a teardrop.

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And that's one of our normal structures on the checklist

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as we move over toward the hip proper on the roof

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is the, uh, acetabulum labeled in D here.

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That's often gonna be a bit reinforced,

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so a little bit denser.

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And then that gives us insight into the joint space as well

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as whether there's any displacement of the femoral head.

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And with regards to the anterior, posterior, uh, walls

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of the acetabulum, we have E here

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and F here, and we can see that nicely on the radiograph.

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E is our anterior wall typically projected more medial on

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the frontal projection.

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And then F is our posterior wall

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typically more lateral on that frontal projection,

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and that's our dedicated hip checklist.

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So hip injuries can be very important

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because of the somewhat tenuous vascularity

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about the proximal femur.

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So in this computer generated image

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to show the vascular anatomy blood flow

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to the proximal femur is supplied primarily by the branches

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of the medial and lateral circumflex arteries labeled here.

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There is some supplemental flow to the femoral head

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that's supplied by the artery of the ligamentum te,

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which is a branch of the opterator artery.

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The green oval shown in the figure here is a transition

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point between that extracapsular and intracapsular portions

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Of the ascending cervical reac arteries.

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So that's our vulnerable zone.

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And the yellow circle is the lateral aspect

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of the femoral head neck junction,

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which is also a vulnerable zone

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where injury poses a substantial risk of vascular compromise

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and can lead to osteonecrosis.

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Now, as mentioned, radiography may be a first line test,

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but CT is often utilized or required

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because it provides a better depiction

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and characterization of radiographically occult

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posterior ring fractures.

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The amount of displacement versus impaction is better

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depicted on CT rotation of fragments.

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Looking at the amount

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or degree of combintion, assessing whether there's effect

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of the neuroforamina as shown here with this

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sacral fracture going through the foramina.

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And then it can also give us a clue as

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to whether there's hemorrhage

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and soft tissue injury that's associated with this.