0:00

Okay, we're half done and we are now gonna go on

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and talk about the Subc Conal bone.

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The second part of our equation here, we have

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to address Wolf's law.

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Wolf was a German anonymous and surgeon,

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and there are many descriptions of what he dis uh,

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put forth in a number of articles and perhaps in some books

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and book chapters as well.

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It's called Wolf's Law.

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I think the best definition is one I found in Wikipedia,

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and here it is, bone in a Healthy person

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or animal will adapt

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to the loads under which it is placed.

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Now those of you who followed any of the articles

0:45

that come out of the bone section at UCSD realize we do a

0:49

lot of investigation looking at imaging

0:53

and then looking at cric sections.

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So through the years, I

0:57

and many others here at UCSD have sectioned a lot

1:01

of cadavers, and I am amazed

1:03

how often when I section those cadavers

1:06

and look at the skeletal things,

1:09

how often I see Wolf's law at work.

1:12

Let me show you two examples.

1:14

Here's a sagittal section

1:15

through the anterior aspect of the knee.

1:18

The tibia below here is the anterior cruciate

1:21

ligament and its footprint.

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Note the collagen fibers within that ligament

1:27

and the parallel trabecula within the subcon bone.

1:32

That's Wolf's law, Wolf's law at work.

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Or look at this example, a sagittal section

1:38

through the anterior aspect of the knee through the patella.

1:42

Here we see the collagen within the quadriceps tendon

1:46

and look at the alignment

1:47

of the trabecula along the anterior aspect

1:51

of the patella wolfs law.

1:53

That's Wolfs law at work.

1:56

And how about one further example here we're looking at a

1:59

section of the proximal tibia

2:01

and we're looking at the result of compression forces

2:05

applied to the articular cartilage.

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Note, these longitudinally oriented trabecular

2:12

and the trabecular chambers,

2:14

we'll talk about those in a moment.

2:16

So that is Wolf's law, a reaction of the bone

2:20

to the compressive forces applied to the surface

2:24

of the articular cartilage wolf's law at work.

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Every time I section cadavers, I see evidence

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of this particular phenomenon.