0:01

Let's turn our attention to the extensors,

0:05

the dorsal aspect of the wrist, the posterior

0:10

aspect of the wrist, and try and match up some

0:14

of the anatomy you heard in our animation.

0:18

We start out with compartment number 1, then

0:21

2, then 3, then 4, then 5, and here's 6.

0:26

That's a little quick.

0:27

Compartment number 1, the abductor

0:31

pollicis longus, extensor pollicis brevis.

0:34

There are innumerable slips.

0:36

Look at these small little slits right

0:38

here in the abductor pollicis longus.

0:41

If this was inflamed, those slits, like

0:44

this one right here, might widen and might

0:46

be confused with a longitudinal tear.

0:49

An important pitfall.

0:51

Then we go from the abductor compartment number

0:57

one, to extensor carpi radialis longus and brevis.

1:01

So it goes longus, brevis, longus, brevis.

1:04

Now we've got to find the EPL.

1:07

Where did it go?

1:08

Well, let's go to Lister's tubercle.

1:10

There is the extensor pollicis longus.

1:12

There's Lister's tubercle.

1:15

Well, now we can try and track

1:18

the extensor pollicis longus.

1:20

Although, we're going to need some

1:22

long axis projections to help us.

1:24

That's compartment number three.

1:27

Compartment number four, the extensor

1:30

digitorum communis and indices, is a larger

1:33

compartment in which one or more tendons

1:36

may be involved in a disease process.

1:40

Then we go to the extensor digiti minimi.

1:43

Compartment number five, this is four, this is five.

1:46

And finally, to the extensor carpi ulnaris

1:50

which sits in the ulnar groove, but as stated

1:53

previously, may perch either to the radial

1:56

side or to the ulnar side depending upon

1:59

the degree of pronation and/or supination.

2:02

But we see there's nothing other than

2:04

simple lubricant around this ECU.

2:09

There's no indirect sign of an inflammatory

2:12

reaction either in the tendon or around the tendon.

2:15

Helping us decide whether the position is correct

2:18

of the extensor carpi ulnaris is physiologic or not.

2:22

We're going to get into the relationship of

2:24

the ECU and its subsheath right here and

2:29

the adjacent structures of the TFC and the

2:32

homo-lateral capsule in a separate discussion.

2:36

The extensor, dorsal, posterior compartment

2:40

highlighting the tendons of the wrist.