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Here's a 14 year old who fell on an outstretched

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hand and now has radial sided snuffbox type pain.

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This injury that I'm about to show you is

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typically associated with fall on an outstretched

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hand, also known as a Fusch mechanism of

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fall, usually with slight radial deviation.

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We've got, on the far left, a coronal

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proton density fat suppression.

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The growth plates are open.

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In the middle, we've got a T1 spin

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echo, which any scanner can do.

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And on the right, a gradient echo, which is

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not typically a bone marrow sensitive sequence,

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although this one does show the pathology.

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So the obvious abnormality is edema in the scaphoid.

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A common mistake is to call this a contusion.

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It is not a contusion.

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A contusion is a bruise.

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A bruise is an ill defined, ecchymotic

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thing that you see in your skin.

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You don't see a line in your skin

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when you have a bruise, do you?

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And you don't see a line if

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you have a simple contusion.

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But in this case, we see a line that is somewhat

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convoluted or serpiginous or irregular in the

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waist of the scaphoid, best seen on the T1 weighted

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image, although if you look very carefully on the

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waist You can see a few spidery lines throughout

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the waist of the scaphoid on the proton density

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fat suppression sensitive bone scan like sequence.

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If you look very carefully and perhaps or

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perhaps not on plain film, you'll see it.

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There is a tiny cortical step off.

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This step off is missed 50 percent of the time.

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On plain film, you may see loss

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or effacement of the fat pad.

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that sits directly radial to the scaphoid.

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So this is a fracture of the waist of the scaphoid.

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I have no problem with you saying

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it's a microtrabecular fracture.

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I have no problem saying, or have you

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say, that it's a hairline fracture.

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But you must use the F word, the fracture word.

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Contusion simply won't cut it.

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Now fractures of the scaphoid are usually

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located most commonly in the trapezium,

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in the mid-pole, 70 percent of the time.

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Approximately 10 percent of the time, distally 20

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percent of the time in the region of the tubercle.

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The blood supply to the scaphoid comes off

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dorsal branches of the radial artery and

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penetrates the scaphoid via various small

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osseous foramina.

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But the pole gets a pretty good blood supply from the

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radial artery branches. And a lot of this blood supply

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trickles on back to the waist and proximal pole.

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So if you whack or cut the middle of the scaphoid with

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a fracture, that blood supply doesn't get a chance to

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trickle all the way back to the proximal pole, and it's

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the proximal pole that's at risk because it's in part

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dependent on the blood supply from the distal pole.

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Now what else can we say about scaphoid fractures?

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That will help us qualify our report.

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Well, we've already talked about this cortical

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step-off that helps you categorize this

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as a fracture, a microtrabecular fracture.

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We also look at these small spidery lines

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and see if there's a clear-cut, consistent

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separation of one to two millimeters.

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And in that separation gap, you'll see some

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high signal intensity, fluid-like signals.

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We do not see that in this case.

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Thus, the designation microtrabecular or stable

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scaphoid fracture is fair to use in your report.

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So 1 to 2 millimeters of high fluid-like signal

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in these lines pushes you more towards an

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unstable fracture or an unstable macro fracture.

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What are some other signs of potential instability?

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Well, greater than 15 degrees of

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angulation of the fracture fragments.

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Also unstable, obviously, would be a

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transscaphoid perilunate dislocation,

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comminution, macrocomminution, and a proximal

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pole fracture would be considered unstable.

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Couple of classifications,

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and by the way, those characterizations of

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stability were described by Herbert.

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The male classification is broken down into

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not stability versus instability, but location.

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Proximal pole, mid pole, distal pole, and as we

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said, 10%, 70%, 20%, and then we break down the

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distal ones into ones that involve the tubercle

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and ones that involve the tubercle with the male.

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The articular surface.

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Let's scroll for a moment,

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and we'll scroll them all together.

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And just let your eye do the walking

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through the yellow pages here.

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And do notice that the intensity in the

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waist on the gradient echo image is far

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less conspicuous and far less informative

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than the two other sequences we have here.

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This is not a medullary bone sequence at all.

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It's an articular cartilage sequence.

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It's a ligament sequence.

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It's a fibrocartilage sequence,

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but not really a bone sequence.

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And as your eye does the walking through the marrow,

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have your eye get adjusted to these little spidery

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lines, both on the T1-weighted image and on the

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proton density fat suppression image, which makes

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this the F word, the fracture word, the micro

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trabecular fracture word, the hairline fracture

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word, not simply the contusion word, this one

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being stable, involving the most common location.

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The scaphoid waist, 70% of scaphoid fractures.