We're lucky to have Dr. Sheehan coming from San Antonio Medical Center to speak with us about posterior labral tears. We get a unique perspective from the military and he thankfully is my senior ranking officer so I get to learn just once again from him. It's just a participation trophy brother, you'll get there. Well thanks so much for having me. My disclosures can be found in the program. And it's great to hear already this morning several of the speakers belaboring the point that instability surgery, whether we're talking about anterior or posterior, is an 180 degree problem and so I think that regardless if we're addressing isolated anterior instability, it's important to be considering that we'll have to do something in the back as well. Several series have compellingly shown the fact that often times these injuries happen in concert. And then the work out of Albert Lin's group in Pittsburgh has shown us that from a pathomechanical standpoint, we know that there's unrecoverable posterior capsular injury as well and so it stands to reason that you not infrequently are going to have those injuries propagating around the back. Just a quick review of the mechanism of injury and how we typically see these, the picture on the left here depicts a more common injury pattern, isolated posterior instability with an axially and posteriorly directed force. However I think it's important also to acknowledge a little bit more of a novel presentation of this, particularly in throwers in which it's essentially a torsional injury starting at the superior labrum and propagating down the back into the posterior band of the IGHL. This video here on the left demonstrates the former scenario, classically seeing that posterior inferior lesion. He also had a fairly large capsular injury down in the back there, which is somewhat of a unique finding. And then on the right here, this is a right shoulder lateral cubitus viewing from posterior, you see that slap injury propagating all the way down into the posterior band in the IGHL. From a history standpoint, we all know that the way that the former scenario presents typically in linemen, they're going to have issues with axially directed force posteriorly. And our military patients oftentimes will complain of issues with push-ups, military bench press, things like that. And then the throwers, not to devolve into a slap talk, but typically tends to be more slap-type symptoms, issues with pain in the acceleration phase of the throwing cycle, as well as decreased velocity, control problems, and decreased endurance, particularly between outings. From a physical exam standpoint, anything that's going to load the posterior inferior labrum is going to evoke painful symptoms, posterior load shift, Kim says jerk test. If we're talking about throwers, we obviously have to be mentioning issues like multidirectional instability and scapular dyskinesis. So inspection remains a cornerstone of the evaluation of these athletes. And then a more novel test that Jim Bradley and John Conway have talked a lot about in recent years, the dynamic posterior instability test, in which you load that thrower's shoulder, you ask them to throw against some resistance that'll typically reproduce their pain posteriorly, and then you recenter the humeral head with an anterior directed force, and that will alleviate their symptoms as well. From an imaging standpoint, not uncommonly, particularly in patients with more subtle injuries, your plane radiographs are going to be fairly unremarkable. From an advanced imaging standpoint, we can see these clefts and these small tears in the posterior inferior aspect of the labrum. Bone loss, we know bone loss is becoming more of an issue. It is in the front. It is in the back, too. This criminal told us that these injuries typically happen in the 740 to 850 position. And then Dr. Provencher's taught us so much about the quality and the nature of the bone loss being anterior inferior, but sloping away relative to the long axis, and we'll talk a little bit about the clinical implications of that. Bone loss is also prevalent in these injuries, and we know that probably the threshold is lower in terms of the danger zone. We've had, in this series, bone loss of as little as 11% portending worse outcomes. Bone block procedures, John Dickens will tell you how to do it. It's a great operation. Not without complication, though, so I look forward to some literature coming forward as far as being able to demonstrate that that's a durable procedure with low complication rate. For the majority of the talk, I just want to spend a few minutes talking about, I think, some keys to solid surgical technique. Patient positioning, this has been vetted in the literature. Really no difference from a systematic review standpoint, lateral decubitus versus beach chair. However, the MOON shoulder group in the last several years has interestingly told us that those surgeons that are doing the anterior instability work tend to have more anchors and more inferior anchors, which I think is a good thing. So this is why I tend to lean towards lateral decubitus for my posterior instabilities. I think angles matter, as we know, in arthroscopic surgery. Portal placement's important. I tend to cheat my posterior portal more lateral for my instabilities, and I think that this really gives you a nice angle of attack down on the front of the glenoid and helps you get that anchor up on the face, which is why I know where it belongs. Seven o'clock anchor, this also has been talked about already. This is really important. Typically 3 centimeters inferior and 1 centimeter lateral to your posterior anchor lets you get down low, lets you put that anchor right where that tear is propagating. I think that that's really important. A capsular shift, an aggressive capsular shift from an inferior to superior direction is also really important. The caveat being that for your throwers, you want to be a little bit more careful and titrate that capsular repair. You're going to treat a thrower differently than you would a lineman. Close the posterior portal. This is a revision case that was sent to me. It was pretty impressive, actually. The posterior infralabrum was actually well intact, but you had this big gaping hole in the back. So however you want to do it, there's a couple different ways to skin this cat, but I think closing that posterior portal gets rid of that stress riser and augments your repair. From the standpoint of what we can expect from an outcome standpoint, taking throwers out of it, in which case the cornerstone should be non-operative management. We know that Jim Bradley's work has showed us that these can be treated successfully. The caveat being is that the throwers, the pitchers, you're going to have a harder time getting them back to their previous level of work or level of competition. So we'll just finish it up here. So in summary, posterior instability presents differently whether or not you're talking about linemen or throwers. Technique matters. Angles matter. So really close that posterior portal and expect excellent outcomes. The caveat being that throwers are more difficult to treat. Thanks, Andy.

posterior labral tears

instability surgery

injury patterns

bone loss

surgical technique