Interactive Transcript
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<v Presenter>This 52-year-old has decreased range
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of motion, without a specific history of trauma.
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And we know from prior vignette that this is a SLAP IV
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with involvement of the superior labrum and the biceps.
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So here is your biceps in the sagittal projection
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and it's sitting just atop
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the superior tubercle of the glenoid.
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Now, the first question you might ask is,
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well, how did he get this if he's had no trauma?
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And typical mechanisms for SLAP lesions include
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throwing.
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And there are two theories
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as to how throwing generates this injury.
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One is deceleration and the other is peel back injury.
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Then the next one is traction.
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The arm gets pulled as if you're walking your dog
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and the dog takes off in the arm jerks.
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The third mechanism is compression
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where you fall on an outstretched hand
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and the shoulder gets jammed, posteriorly and superiorly.
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And then the last one, probably the case here is some type
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of repetitive activity in the face of degeneration
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or mild hypervascularity of the superior labrum.
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And this happens not infrequently in laborers.
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The athletes that get this are pitchers
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volleyball players, javelin throwers, swimmers.
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And typically the symptoms are hard to discern.
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So it's not an easy diagnosis to make clinically
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but things like popping, audible clicking,
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the sensation that the shoulder
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is going to give way,
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night pain and limitation of overhead motion are typical.
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Now I want to talk about for a moment
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the relationship of the biceps to the superior tubercle
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of the glenoid and the relationship
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of the biceps throughout the shoulder as it exits.
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So here is the biceps.
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There is your tear.
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Now we're into the biceps.
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The biceps is torn
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as we elucidated in the companion vignette
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and look how swollen that biceps is,
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but there's more.
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The biceps is not sitting in the bicipital groove.
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It is medially dislocated.
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The transverse ligament is torn.
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The subscapularis is delaminated
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from the lesser tuberosity.
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So we would call this a biceps pulley mechanism injury.
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These two do go together
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and perhaps the instability generated here
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produces an inappropriate tug up higher here
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and results in a SLAP IV,
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or conversely micro instability up here
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results in undue pressure
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and stress on this part of the biceps.
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And it comes undone.
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Either way, there is a potential interrelation
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of these two findings.
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Now, another reason why this is important is one
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of the treatments for a SLAP IV is tenodesis.
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If greater than 50% of the cross section
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of the biceps is involved, especially with length,
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and it is here,
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one consideration is just to cut the biceps out
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and tenodese it in the humerus.
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In smaller SLAP IV lesions,
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they actually get a superior labral repair.
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Now, the last thing I want to talk about
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is the position of the biceps and its takeoff.
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So here's the superior tubercle of the glenoid
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and the most commonly-accepted takeoffs
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for the biceps are as follows
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as described by Tuo Hedy.
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One, completely behind the superior tubercle of the glenoid.
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I see this a lot, almost 30% of the time.
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The next type is
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mostly in the back but a little bit on top.
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This is the most common over 50%, about 56%.
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Then the next most common, perhaps the least common
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at 16% is a balanced to takeoff around the tubercle.
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A little bit center and back.
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A little bit center in front.
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Never have I seen a proven, documented isolated
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anterior rim, takeoff, although this has been described once
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or twice in several reports in the literature.
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So this variation in the way the biceps takes off
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is important because one of the things you want to do
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is determine whether your tear undermines
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or extends up underneath the biceps.
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For instance, most SLAP II lesions
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do come right underneath the biceps takeoff.
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So right underneath here
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is where you're going to find many of the SLAP II lesions.
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On the other hand, in a bucket handle tear,
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a piece of the labrum stays attached
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and a piece of a labrum comes undone.
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So you have something like this.
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So a piece of the labrum stays right here
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and another piece breaks off and sags down.
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So you still have a piece of labrum
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at the base of the biceps takeoff.
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So that's a little bit different.
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So SLAP IIs undermine the base of the biceps.
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SLAP IIIs do not,
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even though there is a bucket handle tear.
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These bucket handle tears are perhaps
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the rarest form of the SLAP lesions.
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So this is pretty much concludes our clinical discussion
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of SLAP IVs.
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Remember that there is an association
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with biceps disease, more distally.
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You should be looking at the biceps labral anchor complex.
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Here is the takeoff of the biceps
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and you see that it is medialized
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or dislocated as part of this process.
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Let's move on, shall we?