0:01

Let's turn now to Glen Al joint instability.

0:03

And I went back and tried to come up with some

0:06

of the definitions that have been applied to this particular

0:10

term, Glen Al joint instability and they vary

0:13

and they even vary, uh, in the same source.

0:16

The one I like most of the six

0:19

that are shown here is the one that I have the arrow next to

0:23

instability is defined as excessive symptomatic translation

0:28

of the humeral head relative

0:30

to the glenoid articular surface during active mo motion.

0:34

I think that's the best definition I've heard to date,

0:38

but there are many definitions out there.

0:41

Now the orthopedic surgeon comes along

0:43

and tries to group these patients who have instability,

0:46

particularly anterior lineal joint macro instability

0:50

or micro instability into two groups

0:53

or rarely as shown here in two three groups.

0:57

I'm not gonna discuss A IOS,

0:59

but with regard to the other groups, you'll hear these terms

1:03

tubs standing for traumatic instability, typically

1:07

unidirectional typically with a soft tissue

1:11

or bone bank art lesion and often requiring surgery.

1:15

TUBS.

1:17

The other group is a little bit more difficult to identify.

1:21

Designated ambry for a traumatic multi-directional,

1:27

often bilateral requiring rehab

1:30

or tightening of the anterior capsule, inferior capsule

1:33

or ship A-M-B-R-I.

1:37

So there are two groups

1:38

and there are all kinds of abnormalities in that spectrum

1:43

that we will be discussing.

1:46

So let's start at one end of this spectrum

1:48

with a pure dislocation of the AL joint.

1:53

Now I'm gonna concentrate on anterior dislocations

1:57

because they represent the majority up to 95%

2:01

of Glen Ural joint dislocations.

2:04

Next would be posterior and then rarely inferior

2:07

or the more rare type is the superior dislocation.

2:12

So let's look at this in more detail.

2:14

With regard to anterior lineal joint dislocation.

2:18

There are four subgroups.

2:21

The first of these is the subcoracoid,

2:24

and what occurs there is the humeral head is dislocated

2:27

anteriorly beneath the coracoid.

2:31

Now keep in mind if it were dislocated any higher than this,

2:35

it would be associated with a fracture

2:38

of the coracoid process, which you can see,

2:41

although that's not the typical presentation.

2:44

So this is a subcoracoid anterior

2:48

lial joint dislocation.

2:50

The second variety is the sub glenoid.

2:53

Once again, the humeral head is dislocated

2:57

anteriorly, but it comes to

2:59

Lie lower down near the inferior surface of the body

3:03

of the scapula.

3:05

As shown here, this is the second most common type

3:08

subcoracoid is the most common type.

3:11

There are few studies that confirm that if you begin

3:14

with a subcoracoid dislocation,

3:17

well all other subsequent dislocations be subor.

3:22

We certainly have seen exceptions

3:24

where the first one's been subor, the next one's been sub,

3:29

but I do not know if there are articles

3:31

that have delved into this in great depth.

3:34

The third type of anterior dislocation is rare.

3:38

It is a sub clavicular anterior glen humeral joint

3:42

dislocation, and here the humeral head displaced anteriorly

3:47

becomes located far medially beneath the clavicle.

3:50

I've only seen one example of a traumatic one.

3:54

I have seen this surprisingly in rheumatoid

3:57

with severe involvement of the glenohumeral joint.

4:00

And then the final type, which is uncommon but not rare,

4:04

and that is intrathoracic

4:06

as typically described in the literature.

4:08

You'll see a picture like this

4:10

where there is anterior dislocation.

4:13

The humeral had driven into the thorax fracturing ribs

4:18

and indeed creating a hemothorax or a pneumothorax.

4:22

But I can tell you in experience,

4:24

what you typically will see will be an ipsilateral

4:28

intrathoracic fracture dislocation.

4:31

As shown here, this particular fractured

4:35

humeral head associated

4:36

with a pneumothorax rib fractures was derived from this

4:40

particular side.

4:42

So this is an ipsilateral intrathoracic

4:46

fracture dislocation.

4:48

Very rarely, and I've seen this in two cases,

4:52

a contralateral intrathoracic fractured dislocation.

4:57

Now that fractured humal head traveled a long distance,

5:02

starting over here, going all the way over here.

5:05

I have no idea what was the pathway

5:08

that was taken in this particular case.

5:13

Inferior dislocations are not common,

5:16

but in fact they're very distinctive here.

5:19

What happens is the humeral head becomes inverted

5:22

and it is driven through the axillary pouch.

5:25

So you can see that the arm is elevated, typically

5:29

often resting on the head of that particular uh, person.

5:34

Just to give you an idea of what that looks like,

5:37

here is an inferior G Glen humeral joint dislocation.

5:41

Now, if you've ever seen a case like this, you realize

5:44

that when they come in,

5:45

they have their arm like this on their head it looks like

5:48

they're trying to ask you a question.

5:51

We had one case shown here

5:53

with two questions being asked. This was a

5:56

Bilateral case

5:57

and you can see that often with lux erecta,

6:01

which is the name for this, there are fractures

6:03

of the humerus, often fractures of the glenoid as well.

6:08

And you may have neurovascular injury

6:10

because of the location of the humeral head.

6:14

And then the other remarkable thing is some patients

6:17

who have a dislocation,

6:19

particularly an anterior dislocation, who have pain

6:24

and restricted motion do not present initially.

6:28

They present later on and during the time

6:30

before they present, they have developed remarkable

6:35

movement in that particular shoulder.

6:38

So although the humeral head is dislocated, look at the size

6:41

of the hill sax lesion that has occurred

6:45

and all of this bone proliferation

6:47

and erosion of the anterior aspect of the glenoid.

6:52

So it's amazing how much movement may be seen later on.

6:58

Now there are a number of uh, maneuvers

7:00

that the orthopedic surgeon will do for patients who have

7:04

anter or even posterior Glen al joint dislocation.

7:10

In this slide, they show you the anterior draw,

7:13

the posterior draw, the apprehension test,

7:16

and the sulcus test.

7:18

These are four of the tests that may be used

7:22

during arthroscopy.

7:23

One of the classic signs

7:24

of Glen joint laxity is the drive-through sign related

7:28

to the capacious anteroinferior capsule widening

7:33

of the space between the glenoid and the humeral head.