Diagnostic Shoulder Arthroscopy
From the portal placement to the CA ligament release, Dr. Patrick Vavken talks us through Dr. Arvind Von Keudell’s conduction of a cadaveric diagnostic shoulder arthroscopy in a beach chair position.
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Table of Contents
- Draw out bony landmarks – acromion, coracoid, soft spot
- Use thumbnail to delineate Anterolateral and Posterolateral acromion
- 2 cm inferior and slightly medial to acromial angle in the “Soft spot” between infraspinatus and teres minor
- Aiming toward coracoid, pierce skin with an 18 guage needle
- Insufflate joint with 50 cc of saline/epi solution
- Make an incision with #11 blade
- Place a blunt trocar through through capsule
- Attach inflow to arthroscopic cannula, suction as well
- Glenoid, Biceps, Humeral Head, Subscapularis, and Rotator Interval
- Visualize Rotator Cuff, check Bare Area, Labrum, and Humeral Avulsion Glenohumeral Ligament (HAGL)
- Create instrument portal through Rotator Interval
- Test Biceps Tendon
- Enter Subacromial Space
- While in the subacromial space, release the Coraco-acromial (CA) Ligament off the bone with a radiofrequency ablator
Hi, I’m Patrick Vavken. This is Arvind von Keudell. We're going to take you through a cadaver - very basic step-by-step diagnostic shoulder arthroscopy.
We’re in a beach chair position. This would be theoretically a 70 degree angle, which is hard to reproduce in a cadaver, and Arvind is going to sort of do the landmarks. Good way to do the landmarks is if you put - push your thumb in a soft spot in between the clavicle acromion and then just follow the outline of your thumb, it will give you a good baseline to get started. Plus, it’s a good stability for the skin because you pushing it down - it’s much easier. And then you get the anterior-posterior corners of the acromion. Run this anteriorly, posteriorly, and around the corner. It’s alright.
Obviously, our patient has some stability issues. You want to make sure you get the coracoid tip. And then what you want - and your AC joint. What you want to be marking from the coracoid tip upwards is your CA ligament, which sometimes you can actually feel through the skin in a skinny individual. It’s typically a Y-shape, fanning out pattern that’s narrower as shown here in the acromion and fans out down on to the coracoid tip as well as base - something to think about it when you go in for a subacromial decompression.
If you follow your posterior part of your AC joint, it will give you your 50-yard midline incision. That's also above your synovial fold - for the bursa. The bursa fold back here anteriorly - be mostly in there. And it should be okay back here.
We will do an - a standard posterior portal, which is about a centimeter medial and inferior to the posterior corner of the acromion. If you want to go in for an instability, you want a bit more medially, a bit more lower, so you get a good angle with the glenoid. If you think about cuff repair, you want to be a lit - little more lat - a lot of little more higher, so you can get good exposure of the cuff through the subacromial space. One thing that we can do first is get a needle. And you don't necessarily have to inject water. It can help - you don’t have to though. Just once you come in, you know you’re in the joint, and if you can move the needle up and down, you know the right - you're in the plane of the glenoid. And again, if you’re doing a cuff, it's not as important. If you're working on instability, you want to stick your scope right where your needle is. You want to make sure that you can go thr - in between glenoid and humeral head without scuffing anything, and like Arvind just did perfectly, stay in that plane so you can see everything anteriorly and work here without causing yourself too much trouble.
Alright, now that we’re near where we want to be, we could inject or just go straight through skin. Again, we like to nick the skin - cut a little bigger. There we go. And one of the things that people don’t really appreciate is if you think about an 11 blade and your 4 or 5 scope, the blade is much narrower than the scope handle itself. So if you just cut with the tip of the scope, we’ll have a hard time just going through a skinny - you’re going to feel a lot of resistance which is not your humeral or not your knee or not your hip - you just have a hard time pushing through. So you want to make sure if you use an 11 blade, just cut a little more or stick it in all the way - either way.
Alright, Arvind is going in. He will be piercing through teres minor, infraspinatus back there, and depending on interaxial rotations, it’s more tendinous or more muscular portion of the - of said muscle - and it’s going to be harder or easier. He's going to follow his index finger and reach for the coracoid, and as you can see, he’s got a nice pop into the shoulder.
At this point, if you hadn't checked - it’d be important - it would be backflow, which there is none in this shoulder, but if you're not sure, it will be a good option to just help you find where you want to be. Alright, coming in. That looks already pretty darn nice. Click in place and start water.
Now how do we get out air bubbles? Air bubbles - you stick the scope into bubble and just let the air escape through the out-flow - or suction. And then just you work your way up in the shoulder and flood the whole compartment.
Alright, number one. Arthroscopy 101. It's called arthroscopy - not microscopy. Here we can see the initial fibroblast of the capsule quite nicely. You want to be pulling back to get better perception of everything and be sure where we are. And that's our first view. We want to see the glenoid, so you want to see the biceps, want to see the humeral head, and preferably even subscapularis. We’re a little high with our portal, but that's okay because we want to do a cuff later on anyway. Just looking at the biceps, you can see the direction of biceps is wrong. It’s not running across the joint. It's tilting down, so our thing is probably sublux, which is okay in this patient. Looking at humeral head, we can see some nice scuffing of the cartilage. Looking into the glenoid - looking at the glenoid, we’ll see bone-on-bone arthritis. Just remember that dead center of the glenoid - right here - is a stellate area where there can be no cartilage physiologically, and that's also how you can tell where the center of your glenoid is. So if you wanted to make sure there was some bone loss, you find this place, you take your probe, and you measure anteriorly, posteriorly - should be the same distance. If there’s some missing anteriorly, you lost some bone, and then you can just take your measurements to see how much is lost.
Alright, now push in a little more anteriorly, and looking down, we can see the subscap down there and the MgO gel across from it. Remember, the importance of the subscap for shoulder repair and shoulder function has been elucidated repeatedly, and especially if you look into Toussaint, Lafosse, and a lot of French guys, it's a - they have really told us what this tendon does.
This tissue high up here, that's your interval - rotator cuff - the rotator interval. This is where the shoulder freezes. This is the AOA and breathe the inner shoulder, and just as in ATLS, this might be one of the most important things and most important steps in any shoulder surgery. This tissue is really important. Don't destroy the vein. If you don't have to put a portal in here because all you want to do is just a quick diagnostic scope and a subacromial decompression, think about twice before you go through it because it's going to scar down, and it’s going to cause some stiffness, alright? What’s the stiffness that’s going to get caused by it? We don’t really know how frozen shoulder happens. We just know it has myofibroblast infiltration, and it starts right here in interval. Right, and then functional-wise, they will probably have some - if you think about how your shoulder moves, if you’re going to rotation, it’s really - it's in here - that’s where it freezes. And if you don't get that motion in there, it’ll be stiff, you’ll lose external rotation, and it’ll stiffen up from there. Same time, if you’re unstable down here, it's because this opens too wide, and that's where we do a closure.
Alright, now let's look at the cuff - look at the cuff in beach chair. We want to make sure that we go in a little bit of abduction, alright? You can see the top of the glenoid. That could be construed as a drive-through sign if we just fall in, which is correlated with laxity, but not indicative of a labral tear instability. Now looking over laterally, we have a great view of the cable. Stephen Burkhart - it's too bad that he's not here. You can see the cable running across the head, which is just beautiful. This is where all the force runs into the shoulder, the cable construction, and down here you can see the crescent of the cuff where small tears happen. If there was small tear in here, the stability is here. So this is the tissue you want to reproduce and create - and make sure that it's intact.
Now we see nice - nice insertion of the supraspinatus, so we’re probably not repairing that one today in here. Coming down laterally, we can start to see the bare area and the infraspinatus. Now as I said earlier today - keep going down a little bit - as I said earlier today, this is a bare area because you can see tendon, a little bit of bone, and intercartilage. If you saw tendon, little bit of bone, intercartilage, little bit of bone over here, that will be a Hill-Sachs lesion. This guy does not have a Hill-Sachs lesion. Coming down teres minor, going down into the inferior recess, he does of osteophytes. There we go - and looking over the labrum.
Now, if you're - if you're working an instability, one of the most underappreciated defects is right here - your HAGL lesion. This way - this way - this way - this way - this way. You want to make sure that you see your capsule as it inserts into the - underneath the humeral head - because this is the hammock right here. If you only tighten on the glenoid side back here, but if you have a tear in the capsule down here, all you do is you pull the tissue over it - there’s no - going to be no stability - that's where the HAGL lesion lives - the humeral avulsion of the glenohumeral ligaments. There might be a little something in there actually, which is okay because it’s unstable. It’s just old age.
Then we come up again. We can see the glenoid and the labrum. In a beach chair position, if you want to create some space, you will take 4 or 5 towels, wrap them up, you’ll take the fist of your assistant, and just stick it under the head. Can you see how that opens up? Just stick it under the head. Do not pull - you’re not pulling the patient off the bed. If you pull on your spine or something, you’re pulling patient off the bed, kinking his neck, causing some issue that makes your anesthesiologist scream. You just stick a fist in there, a couple of towels, and all you got to do is actually abduct over this fulcrum - and see how nicely it opens up? You can't see anything - there's all your labrum. Let’s look anterior, inferior for a second. 3 o’clock. Again, you can’t see anything, and here is your labrum.
Alright, well now at this point, we decided we're going to go in and do a little bit of a debridement. So we will find our spinal needle, and we want to come right through the triangle - dead center. That’s okay - maybe a little high.
Do - you can always control depth through your index finger, and as you talk to other people and reach for something, you won't be falling out or anything. The other beauty is whenever you use a needle, your fingertips will be pointing at each - each other. So you're really going for your middle finger fingertip, which might make things a little easier in here. It's a lot easier in elbows, and if you want to see a good elbow video, I think there's one on the web page - because you’re just pointing finger to finger. Alright.
Then you get your knife. Remember, it's not just position - it’s also direction and everything. So we’re going to try the - and then just roll, and - you’re rolling through the tissue. There you go. Now with your switching stick in, you can already test for labral stability. You can test for biceps tendon instability, which is the Ramp Test, so if you want to push in a little more and try to see where the sulcus of the biceps is - top lateral.
So you can see, the biceps should be sitting in here. Alright, and now as you push down, you can see how - first of all, you see more of the body of the - of the biceps tendon. There's a lot of provocations - a lot of research that would in fact - that if you look at a biceps tendon intra-articularly, all you’ll see is about 1/3. And a lot of pathology is going to be down that tunnel, and you won't be able to see it. You can push your scope into the tunnel a little bit and look down and see a little more, but you know, if you see the injection, it’s probably going to be hurting down in there too.
Now, if you pull back in and then use the tip of your - whatever instrument you have - and try and pull on the medial sling and the lateral sling, and if you see - see if you can push away that tissue - see if I can push away that tissue. See that's - that's in there. That by the way - that’s the comma sign. So you can see this tissue running down from the subscap into the supraspinatus. If both are torn, that's the famous comma tissue right here - so leave that. Don’t - that's nothing to debride. Leave the stuff that’s important.
So Arvind is going to show us the Ramp Test now to check for biceps stability. He's going to use his switching stick first of all to go on top of the biceps tendon and pull it in medially, and you can see, it’ll - it’ll come out of it. You can also judge the outer surface of the biceps tendon. You can look down into the biceps tunnel a little more, which looks good, so at this point, you’re going to use the switching stick - switching stick and check for your mediolateral sling. Level off the comma tissue in between subscap and biceps tendon. See if that’s stable - it doesn’t displace - and then you come across and check the lateral part of the sling, which looks good. Alright.
Alright, at this point, we’d be happy, and we'll go subacromially. In order to go subacromial, we’re going to take out the camera, bring back the obturator into the trocar. Now pull back. We go up. We feel for the corner of the acromion, all the way up - index fingers going to be on coracoid again. And you come across, and you try and touch the CA ligament here, which like - you should feel a pop as the trocar comes - swipes across the CA ligament like that. There’s a little - there it is - a little - our - that’s our CA ligament. That’s what cleans up the bursa a little bit, and that's where we want to be because eventually - we can just leave the camera here or there. We want to be in a place, right there, that if you come in, we’re going to see the CA ligament. So right now, down in there, we’re going to change for the camera.
So we want to be looking straight up and a - maybe a little laterally. We want to be just a little anterior of the 50-yard line. Because I pin my - my - my - scope - instrument there - and… There you go. Alright. So what you can do is just pull back a little bit here. Alright. My personal favorite is I'll just shave out as much as I need to shave because it’s going to bleed anyway, and then you find your bleeders. There’s always one big bleeder posteromedially, so there’s always going to be some bleeding back there. And then there's the thoracoacromial ligament - excuse me, thoracoacromial artery running with the coracoacromial ligament. There’s going to be some bleeding up here. So you get the bleeder here. You get the bleeder there. Everything else should be taken care of by the epinephrine in the bag. You don't necessarily have to go way too medial because we can see the cuff, and we can see everything.
We just want to make sure that there’s no adhesions on the cuff laterally / anteriorly. So that big band that runs down anterolateral - that I get.
So now we're looking subacromially. We can see the shiny fibers of the CA ligament at the anterolateral portal of the acromion. Alright, an important thing is not just take away everything - we’re just releasing the CA ligament off the bone. You can see it actually loops around the corner of acromion. It can be sticking on the undersurface, causing impingement just by tissue, and that can go - or we’ll want to leave the most anterior part - just release if off the bone. It’ll scar back down again - give us some anterior, superior stability of the shoulder in the future. You can now see Arvind just scraping off the ligament from the bone, and you can see how the tip is just fol - starting to fold down with the release. Come across laterally. There you go. Yep. Very nice.
Now we want to clear off just the acromion - not open the AC joint. That's one of the little things to remember. Okay, so Arvind did a great job releasing a CA ligament of the acromion. You can see ligament running down here, dangling in there. These are fibers of the - last few fibers in there are delt’s fascia actually. There’s a little loose body, and we’ll take out in a second. And then looking up, you can see the anterolateral corner of the acromion. We don't see much of a spur, so we don’t necessarily have to take that off. There's no evidence proving that it will improve outcomes after cuff repair. If you use a pass-through, you want to make sure you have enough space to work, so sometimes you’ll take out some bone. When you take out bone, remember on the X-ray, not just to look on the outlet view for A, B, C types - actually 1, 2, 3 types - but on the lateral, you want to make sure that the acromion is actually thicker than 8 millimeters, so if it take off 5, you leave some bone. I was researched by Dr. Schneider, back in the day - never published really - it's only an abstract in JBJS - but he looked at some like 200 cuff repairs and found that in the type 3 females, about 1/3 had an acromion thinner than 8 millimeter, so if you took off too much with an acromioplasty, you have a high risk of a fracture after really. Alright, awesome.