So, I think maybe as a junior guy you get this topic. Just out of curiosity, how many people in the audience are doing high tibial osteotomies? Good. And how about posterior lateral coronary reconstructions? Yeah. Good. So, all right. I won't go blazing fast through this then, but I will say a few comments first. I think, you know, this talk was supposed to be based in primary ACL reconstruction, so maybe not super applicable here. You know, obviously fix the things that are torn. So in the posterior lateral corner, obviously if they have concomitant injuries, you want to fix that at a time of a primary ACL reconstruction. I think if you think of the high school or collegiate level athlete who may have a little bit of varus malalignment, it's going to be tough in a primary situation to talk to that athlete or that athlete's family about doing an osteotomy at the time of their primary ACL reconstruction. So maybe more applicable in the revision setting, or as Volker nicely mentioned, why do these fail? Or when you're looking at reasons for why someone's coming back after what looks like a well-done technically ACL reconstruction, that's probably the time to start keying in on some of the concepts we're going to talk about this morning. This was a really nice paper, and you'll see a common theme here. You know, a lot of the work done on these topics was done by Rob and his group, and this kind of sums up everything you've heard this morning, basically. All the concomitant things that you need to be thinking about with the ACL reconstruction. So I encourage everyone to grab a copy of this recent article. But they did a systematic review, looking at a number of studies, and what they found obviously is that there's a number of studies looking at the posterolateral corner as a reason for graft failure, and the same with the varus knee. So when I think about these two topics, I think about posterolateral corner injuries, I think about alignment, and I kind of break them down in my head into the acute injury. So when someone comes to you with an acute ACL tear, maybe a little less important to focus directly on their alignment, but very important to make sure we're not missing concomitant injuries, as you've heard about from the other great talks this morning. There are areas that we need to highlight, including the meniscus status and the other ligaments of the knee. And there's a number of great papers from across this country and the world, from the UConn group as well as Dr. Harner, noting that if you miss a posterolateral corner injury, or if you reconstruct the ACL in a posterolateral corner deficient knee, you're looking at potentially a failure. So in terms of ACL injuries, probably somewhere around 15 to 20% will have some type of concomitant posterolateral corner injury. And when you see these big or violent mechanisms, you probably need to key in on a potential posterolateral corner injury. Rob's done devoted his career to really showing us some really nice anatomy of the lateral side of the knee, as well as the medial side of the knee, and the main structures, as everyone in the room is aware, fibular collateral ligament, popliteal tendon, and popliteal fibular ligament. There's a number of other stabilizing structures, and some of the great work Alan and Volker do, looking at the ALL and lateral extra-articular tenodesis, certainly apply here. In terms of your physical exam, obviously if you're concerned about the posterolateral corner, potentially a knee dislocation or subluxation, ruling out any type of vascular injury is going to be really important. I think this also goes back to what I teach our residents and fellows, everyone in this room is busy in clinic, and you're trying to rush and see patients, and sometimes the MA doesn't put them into shorts, so you just examine them with a pant leg rolled up. You may not watch them walk, you may not ask them to squat or move. So I think in the chronic setting, when someone comes in with ACL deficiency for a long period of time, I think those are all important things. Obviously with the acute injury, a big swollen knee, they're not going to want to squat and walk around the room for you. But if someone has dragged their feet on taking care of their ACL tear, and then they come in and see you, it's probably worthwhile to have them walk, look for various thrusts, see how they squat and stand, etc. In terms of the posterolateral corner, important maneuvers, you have the dial test, posterolateral drawer, you can reverse pivot shift them, and obviously if they have any reek or bottom, you should be concerned for something aside from just the ACL tear. These are the two main classifications. Most people, I think, use the grade 1, 2, or 3 based on the degree of laxity, however the finale classification is also important, as we'll see with the varus thrust and double and triple varus. So back to Rob's great work, serial sectioning, what you see is that as you get rid of the posterolateral corner structures, you see significantly increased ACL graft force with varus loading, or varus and rotational loading. Again, pointing to the fact that if the patient doesn't have a posterolateral corner or intact posterolateral corner, they're going to struggle with their ACL reconstruction. Rob has also highlighted the importance of stress radiographs, so anyone where you're concerned that they have a stress radiograph, you can see someone holding the thigh with a lead glove above getting these stress radiographs, and I still routinely do this 20 degrees of knee flexion and 0 degrees of knee flexion in the office. Again, it takes time out of a busy schedule, but I think it's clinically relevant. The other time to do it is if you can see clearly on the MRI that they have posterolateral corner structures injured, doing it at the time of surgery, having the fluoro come in before you prep and drape, I think is very appropriate. Just the UVA group kind of corroborated what we've seen from Rob's group, and that stress radiographs are important, and with posterolateral corner injuries, you'll see increased opening. MRI is really sensitive to pick up these injuries, so obviously we all get MRIs for our primary ACL tears. Bone bruising patterns may change a little bit when you have a combined posterolateral corner injury, so keep that in mind. Look on the posterior medial tibial plateau as well. Non-operative management may be great for isolated or even combined grade 1 posterolateral corner injuries. There's been some historic studies. You can see these are older studies, but grade 1 injury is probably okay. Grade 2 and 3 injuries is when we need to start talking about reconstruction. People looked at repair as well, and probably for the acute avulsion off the fibular head, a repair is probably a reasonable option. However, when you start seeing mid-substance ruptures, stretched-out ligaments, probably reconstruction is the better way to go. So that's really the take-home from this nice study by Dr. Leprod, acute repair of aval structures. Anything mid-substance or stretched-out or in the chronic deficiency state, reconstruction is probably your best bet. So really there's a paucity of literature on doing these as repairs at the time of reconstruction of the ACL versus a reconstruction on the lateral side, however, reconstruction is probably better than repair based on what literature we have available, and another study by Dr. Leprod, again corroborating that. So where does coronal alignment come in, in my mind? Well, I think in the primary ACL reconstruction, pretty limited role, as I mentioned earlier, with that high school athlete. It's hard to say, listen, you have a little bit of varus, we're going to do an osteotomy at the time of your primary ACL reconstruction, but I think when people have chronic deficiency of the ACL, and they're coming to see you after a long period of time without an ACL, they probably do have concomitant, as Volker mentioned, meniscal pathology, chondral damage, and they're going to start to see some alignment changes. So when we get into these terms of double varus and triple varus, when we're talking about bony change plus a lateral sided laxity, bony change with lateral sided laxity and a thrust, those are the times when we're starting to consider changing the alignment. This was a really nice study where they looked at the ACL graft tension, and when they shifted the axis 50%, so 50% into the medial compartment, they still didn't see a really significant jump in the ACL graft tension. However, when they went all the way to the medial side of the knee, they saw a significant jump. So really that's, again, evidence to support when you see double and triple varus, that's when you need to start considering osteotomy. So what about in primary varus, where there may just be some medial compartment change? There's really no difference with ACL graft survival in primary ACL reconstruction. It's really when you get into double varus where we see doing the osteotomy, either in a staged fashion or at the time of ligament reconstruction, that we start to see some differences in Cincinnati knee scores and patient reported outcomes and stability long term. So really, this is one of the seminal works on this by Dr. Noyes and his group, and they recommended a staged ligament reconstruction after an osteotomy in these patients, and I think that's a good way to go. And the other evidence that you can point to to support this is this paper by Dr. Lepraud and his group, where they actually had 40% of patients who were in the double or triple varus category, and 8 of the 21, or 40%, had sufficient improvement in knee function after just the osteotomy. And in that group, you can cheat the plate so that you change the slope a little bit too, which will help stabilize those knees in the chronic ACL and posterior lateral coronary deficient knee, and those patients didn't have to go on to have additional ligament reconstructions. So this is a paper by Brian Waterman, just talking about his thoughts on a changing alignment with ACL reconstruction. Again, he pointed to more severe single varus and double varus as reasons to do, excuse me, reason to do osteotomies, however, he pointed to, again, changes to the meniscus and cartilage, which would also force your hand. So as a summary, I think in the acute setting, obviously identify concomitant injuries and pathology and reconstruct those torn structures. Probably in the early ACL, posterior lateral coronary reconstruction group, there may not be a real need for the high tibial osteotomy, however, when you're in the chronic setting of ACL deficiency, this is when you need to start keying in on osteotomy as potential either a first option or only option in these ACL deficient posterior lateral coronary knees. Thank you very much.

ACL reconstruction surgeries

concomitant injuries

alignment issues

osteotomy

staged ligament reconstruction