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So pulley lesions have been recognized over the years

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with increasing frequency due to growing popularity

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of sports such as rock climbing.

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It results from a forceful finger flexion

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with MCP extension, PIP flexion, and DIP extension.

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And if you look at any pictures of rock climbers hanging off

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the face of, of these rock surfaces just

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by their flexed fingers, it would not be surprising

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to imagine that a pulley lesion could occur

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a two being the most common pulley lesion.

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When we first started to explore these pulley lesions,

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we thought, gosh, we'll put

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contrast into the flexor tendon sheath

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and that will help us identify the pulling.

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Well, that wasn't the best idea,

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but it did give us some insight into the fact one,

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that the flexor tendon sheath is fenestrated.

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And so we had contrast leak out into these cric specimens.

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It did then subsequently,

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however, outline the superficial surface of the pulley.

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Here's a two, here's a three, here's a four ultrasound.

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This not high resolution ultrasound,

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but more contemporary high resolution ultrasound can show

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the pulley with great fidelity, very similar to MRI.

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And what we found in looking at MR, is that

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as we look at standard MR sequences in the axial plane,

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if we cross reference to the area of the A two pulley,

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we would see the anchors of that pulley very easily,

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particularly on the non-fat suppressed sequences.

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And so that was the way that we identified them,

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forced flexion across the finger.

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Then that tendon

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with intact pulley should stay intimately associated

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with the bones when the pulley is insufficient.

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The secondary finding of both stringing identified, again,

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that is shown in both the axial

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and the sagittal imaging plane

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and injuries in patients here, very classic appearance.

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So here you're seeing a normal pulley,

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the marker placed on the symptomatic finger.

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Classic. This is neutral position of the finger, the halo

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of altered signal intensity

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around the palmer aspect of the tendon.

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Very slight separation of the tendon from the bone

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without forced flexion.

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On the sagittal images, you really don't see a whole lot,

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but you have the absence of that pulley

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and the halo of edema that are very consistent

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with the diagnosis in this case of the A two pulley lesion,

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of course, at the level of the proximal phalanx.

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Another example, they all look the same.

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Halo of high signal intensity, the diastasis

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or separation of the tendon from the bone in neutral

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position, no forced flexion in this case.

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And of course, I have to show you the pulley of the thumb

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because that's my pet peeve when people are talking about

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finger and thumb pathology,

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because at the thumb we have the A

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One pulley, the oblique pulley,

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the A two pulley at the level of the interphalangeal joint.

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And when we're looking at the pathology, very similar here.

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So sagittal T one fluid sensitive sequence

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as you look at the Palmer aspect,

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high signal intensity here, very slight separation

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of tendon from bone in the axial imaging plane.

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Here you can see that high signal intensity

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of the Palmer aspect of the tendon.

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You see the discontinuity here posteriorly

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or at the Palmer aspect, rather of the articulation

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and the separation of the tendon from the bone.