Thank you very much. Thanks, Justin, for helping me with this. Lessons learned over 29 years. First of all, there's many pathologic theories in the literature. My take on this is usually it's a combination of above and enthrowers. Muscular imbalances of lats and pecs are a big deal. Last two papers I reviewed, you know, everybody thinks it's anterior. Well, it's not anterior. Fifty percent in the first paper from ASES when I reviewed were posterior or a combination. In the next paper of 167, 26.3 percent were isolated posterior injuries. It was the highest frequency of any of the ones they looked at around the glenoid. So posterior, especially in athletes, is really significant. It's more common than anterior. First significant paper we did, Jimmy Tavoni and I back in 93, chronic overuse led to microtrauma to the posterior capsule, capsular attenuation, posterior subluxation, and then Lee Kaplan in 2005. We did the NFL and we found that offensive and defensive alignment had a higher propensity with offensive a little bit more. We also found that overhead was an indirect method and contact was a direct method. It was fairly clear. First thing I want to teach is etiology in overhand athletes is different than contact athletes and so is the treatment. So these are the causes and throwers. Jimmy brought us the microtrauma one. Then Burkhardt and Kibler was posterior contracture, which I think is a smaller part. Slap extension I think is a big part, Ben and I, and Neil did that one, and then dynamic posterior instability in throwers is becoming more and more common. You got to remember, to get from a 2B slap to a type 8 slap, which is the whole way down, a normal labrum has to be a mobile tension band. So the superior labrum is a tension band and the inferior labrum is a fixed organ of compression. And the top of the labrum in a good thrower has to move. It's got to be mobile, but it can't be torn. So there's three problems happens when the slap tear disrupts below the equator. The three problems are the superior labrum cannot function as a tension band. The inferior labrum now is mobile. There's no compression, and that's where the head likes to live. And the inferior labrum and the posterior band of the IGHL, you lose concavity compression, and that's a big problem in throwers. So this is the tears you're going to get, and I'll show you a little better. There and all along there, you're going to have two specific tears, and we published this already. So John Conway coined this term the lambda tear, and you can see it. You see my probe going into the labral junction, the labral glenoid junction. That's one part of the tear, and that's the split in the other part of the tear. And remember, the labrum has three different layers. So it splits in the top, and then it splits into a Y. That is a thrower's type 8 slap. The findings that predict the poor response to physical therapy. So the first one is that they have a circumduction test like this. They don't do well without surgery. If they just drop out of the back of the shoulder like that, they also do not do very well. I can't read him. This is the dynamic posterior thrower's test that we developed, John and I. This is a thrower. We put him in a throwing motion. You ask him to push down with his elbow like he's throwing. His shoulder slides out the back, and then we ask him, where's the pain? The pain's in the back. Then what you do is you do the exact same test, and you put your thumb over the back and push forward, and their pain will go away. We just finished a study on that with Tracy Lawyer and Mike Nicolai. It was a 94.4% positive predictive value for a bad slap. This is the PIT 3-pack, or slap thrower posterior 3-pack. Active compression's positive. The D-PIT and modified D-PIT, which I just showed you, and then this Whipple and modified Whipple. The same thing. Put their arm in front of them, push down on their arm, and then block them. They'll have pain, and then the pain goes away. Beware of hypermobility. You do not treat them the same. Posterior instability in the face of hypermobility, a laxity state like Ehlers-Danlos, this is a different topic. Remember, Ben Kibler's talked to us about scapular dyskinesis. Well, there's three types, but they're not pathologic specific, but here's the caveat I'm going to give you. These kids will protect their shoulder from posteriorly subluxing by moving their scapula forward, and they'll have scapular dyskinesis. The only way you can fix them sometimes, after they do this so many times, is to fix the posterior capsule, and then their scapular dyskinesis goes away. My partner, Craig Morrow, and I looked at bone loss, beware of bone loss. The first paper we came out of 200 repairs, it was bony width that was predictive. Smaller glenoids, not bigger glenoids, smaller glenoids, and not bone loss, but we didn't believe that. We just couldn't figure it out. Then the military mafia, they're sitting over here somewhere, I know, there they are. So the military mafia, they came out with 69% of their posteriors had bone loss, and 5% of them had subcritical bone loss, all right? But what they found out was that the reoperation rate, complications, patient-reported outcomes between the groups were exactly the same. Then we just saw this paper by Justin, we did this paper, Matt and I and Justin, and we changed the way we looked at it in CT scan, and the point was that this pattern of bone loss is distinct from anterior glenoid bone loss. Posterior is much more abrupt and steep, like falling off a cliff. Then we talked about this study, posterior location and anterior is not the same. Look at the posterior, it goes 30 degrees off axis, that's where it comes out posteriorly. Anteriorly, it goes straight up and down, all right? It's a totally different, it's really the posteriors from 645 to 930s, and it's in a different quadrant, and 30 degrees off axis. If you don't measure it that way, I'll tell you, if you don't measure it that way, it's a problem. So this is the paper you want to take home, this is the take-home message that I want to give you. Matt and I and Justin did this, the risk factors for instability are increased glenoid bone width loss, so it's a smaller glenoid, and greater glenoid bone loss. The numbers were 11% bone loss equals a 10% failure rate, 15% bone loss is a 25% failure rate. So once you're around 15%, we got to think about doing something else. And failure to reformat the MRI sequences to obtain orthogonal cuts will overestimate the percentage of bone loss, so you got to do it when you think about it. We looked at retroversion, Craig and I, and we found that retroversion didn't make one bit of difference, okay? In 200 cases we operated on, that's a large Ohio University tight end that I fixed just the labrum, I didn't do anything to the bone, he's been in the NFL for years now. There are critical findings on the MRI for posterior instability versus age-matched controls. The three of them are glenoid dysplasia, posterior humeral head supplementation, and increased capsular volume on the MRI. Each one of those is an independent risk factor for labral tears who develop posterior instability. So if you see it, you got to start thinking about, this guy's going to get into a posterior instability problem. Next thing I want to teach is posterior pathology is rarely isolated, it's slaps, it's partial cuff tears, it's raggles. So I have a prospective group now of 830 of them I've operated on, and the current group, prospect group, 40% of them had additional pathology of sometime either a partial cuff tear, they had this peelback lesion, something else is going on. Remember, there's concomitant pathology, this is an NFL linebacker from the Miami area. You can see, this is how I got his MRI, I know this is posterior instability, but look, it's a big haggle lesion, and you can fix it easily arthroscopically if you just know ahead of time where to put your portal. These are some of the ones I didn't know I had. This is a baseball player, this is an old thermal, that's an NFL football player. Those just surprised me, so you got to know how to fix those arthroscopically. Here's my tight end that caught a touchdown pass in the end zone, dislocates his shoulder, I have to relocate him in the locker room with some Marcane, and this is what I see when I get in there. The question to you is, what do you do first? Do you do the labrum first, or do you do the capsule first? For me, I do the capsule first typically, and then I'll know how to tension the labrum. You can do it the other way, but I get scared that I'm going to take too much of the labrum, I won't be able to close the capsule. Justin did this with us, we were looking at what about posterior instability in the face of a partial cuff tear that we didn't fix, didn't make any difference at all. As opposed to the slaps that were published before, pure posterior instability and rotator cuffs does not make a difference in return to play, or return to play at the same level. Then we looked at our four-year follow-up of these type 8 slaps. We thought, well, you know, we're fairly good at it, well, we weren't very good at it, but the throwers had increased pain, decreased function, decreased return to play, but it was a mean of 6.6 years, but they had a very high satisfaction rate. So early on in the study, I started switching to Nautilus. I'm going to tell you right now, please go to Nautilus and use something that has polyester in it, because cells don't like polyethylene, but they really like polyester. So why do I use it? They're faster, they're lower profile, we did the pull-out and pull-through strengths are extremely, they're like 39% better, more consistent tensioning, and it may better restore the normal meniscular anatomy. We did this one also, should you use Nautilus or should you use tapes? Well, tapes, it's better return to sport rate and a decreased failure rate, so try to use tapes if you can, Nautilus. What about overhand athletes? A little loose is always better than too tight in these overhand athletes. This is the first study, and you could see that the throwers and the non-throwers return, but not at the same level. So you've got to tell the parents, if you've got pitchers, they're not going to return at the same level as the rest of them. Then we said, well, wait a minute, what about contact athletes? They have better outcomes, a better return to sport. A little tight in them is always better than a little too loose, that's when they do better. So we looked at our first group of 117, we had great ASES scores and stability, but ASES scores are not great scoring systems for athletes. A KJOC score is better, and we've already moved to that. Then we said, what's the best of the bunch? So we did 70 American football players, Justin helped me with it, and they were the best by far. 93% return to sport, 79% return to sport at the same level, and they had the highest satisfaction rate of all. So if you want to operate on posterior instability, operate on an American football player. These are my indications for surgery, failed rehab of greater than six months, a large labral or flap tear on MRA, posterior glenoid bone loss at about 11, which is an increased 10% failure rate. I want to get to them before they get there. Small glenoids, like 24s, I really worry about those, raggles, capsular rends, or unable to return to sport at the same lesions. These are my indications for surgery. We've looked at our, started back in 2005 was the first group I looked at of 100, and we had 91% good to excellent results. We wanted to move to this KJOC scoring system. The next 200 I did, we looked at them and we said we had 93% good to excellent results, and that was true for everybody across the board. But what we found in this group, this is the first time we found that suture anchors are important. So anchors group had a better ASES score and a better return to play sport. So when in doubt, use suture anchors of some type. And we had great return to sports with that group. What about adolescents? All right, this is different than anterior. These people do really well with this operation, adolescents. We did 110 of them, they had 88% good to excellent results. So it's a very reliable treatment for unidirectional posterior instability in the adolescent group. We looked at our revisions, you always got to look at those. So these are no-throwers, 297, we had 19 revisions, and this is what's important, female, dominant arm, concomitant rotator cuff, three or less anchors, and decreased bony width. This bone loss is an issue. Our revision rate is 6.4 at nine years of the overall group. Then we did the contact athletes, they were better, 186, 11 revisions. The risk factors were none of the other ones. The only thing was a smaller glenoid bone width was the only risk factor. This was the only risk factor of that group when we looked at it. So our revision rate was 5.9% at 12 years, then we looked at the thrower group, they were the worst. I did nine revisions in 112 of them, and the risk factors. So the revision rate now goes to 8.2% at almost three years, but the revision factors were female and decreased pre-op ASES scores. Finally, we did a meta-analysis that won the award from the AJSM. We looked at 10,035 publications, 607 were assessed, 53 were unique, and this is what we found. Well-defined outcome studies were lacking, arthroscopic treatment is effective and reliable for outcome score satisfaction return to play, suture anchors resulted in decreased recurrences, decreased revisions in young adults, and arthroscopic was better than open for satisfaction, stability, recurrence, return to sport, and return to play. Once again, though, the throwers were less likely to return to the same level versus the contact athletes or the overall population. Thank you very much from the city, the real city of champions.

posterior instability

athletes

muscular imbalances

suture anchors

arthroscopic treatment