0:01

Okay, we're gonna move on now

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and talk about the Bennett lesion.

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So the Bennett lesion is a common finding

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in the throwing shoulder.

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It's been associated with pain, with impingement,

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particularly postal S impingement

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and subluxation of the humeral head.

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So what is the Bennett lesion and what is the controversy?

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Well, the main controversies relate to the fact

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that some people think it is not

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clinically significant by itself.

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It's been found both in symptomatic

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and asymptomatic forwards.

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And the other controversy relates to the fact that

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what produces it.

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Typically people suggest traction.

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But is it the triceps, the posterior capsule,

0:49

or the posterior band of the inferior numeral ligament?

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That's the debate. But let's go ahead and look at it.

0:56

When there's contracture of the posterior capsule

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or the posterior band of the inferior glen ligament,

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tensile forces can be produced at their sites of attachment,

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particularly during caulking

1:11

and deceleration phases of throwing.

1:14

And over a period of time, the development of an ESOL fight

1:19

at this ligament or capsular attachment can occur.

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Typically, we see this posteriorly postero inferiorly

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or posterior superiorly,

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and it can extend over a long distance.

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Let me show you some cases.

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So here's an example of a Bennett lesion shown

1:37

by conventional radiography.

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The black arrows indicate its extent shown by a sagittal mr.

1:45

Between the black arrows here,

1:47

probably occupying about four hours of the glenoid.

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And this is what it looks like in the transverse plane.

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There was labral pathology in this case.

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So this is the Bennett lesion.

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Here's another one located a little more postal inferiorly

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shown by CT and by Mr.

2:07

A broad expressions extending over a few hours

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of the glenoid face.

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Fairly well defined on, as shown on the CT uh images.

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And here's another one associated

2:20

with posterior labeled detachment.

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This one extends over a broad distance,

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probably from about seven o'clock to 10 30

2:28

or 11 o'clock in this case.

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So these can be quite extensive.

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How significant they are could be debated.

2:38

So let's review to this point what we've said.

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Primary abnormality that may occur is contracture

2:44

of the posterior capsule

2:46

and posterior band of the inferior glen ligament.

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This can lead owing to tensile force to a ben lesion.

2:55

It may in fact lead to a poster superior shift of the

2:58

Glen Al contact point, allowing further

3:02

external rotation at the price of limitation

3:05

of internal rotation.

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So-called gerd.

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This particular postero superior shift in the contact point

3:13

allows excessive external rotation,

3:16

but it may contribute to poster

3:19

superior internal impingement.

3:21

And all of the, or these two factors can account for

3:25

a propensity to develop a lap lesion.