Thank you very much, I'm going to get right into it. Aishish and I did fellowship together, so about 13 years or so in practice, do mainly knee surgery and a lot of this is ACL. So I'm going to talk a little bit about the complex cases and what to avoid. There's a nice paper series we just published in Kestrel Journal earlier in the year on current trends if you're interested. On the left you see what sort of worldwide the graft choice is and I just put this out there since on the right that's my graft choice and like Al Ghatgood mentioned, we're doing a lot more quadriceps tendon these days and especially with the Stability 2 study, quad and BTB mainly. In the revision setting, quad tendon is really the most commonly used graft in my practice and that has changed over the last 5 to 10 years. Big question is, why does ACL surgery still fail? There are many, many reasons. I wish it was just the slope. I know I was asked to talk about the slope, I'll talk about a few other things as well. Tunnel malplacement is still the number one cause and then there's this thing about biology and you just don't know why it is that certain grafts fail and what the milieu is in the knee. A little bit about lead, of course, has already been talked about but we kind of arrived at this point right now where we figured out through Al's study in Canada that using an LAT or some sort of anti-lateral augmentation will help reduce failure rate. That's the current status. When you look at the layers here, there's obviously the IT band is the main governor of anti-lateral instability. There was a consensus meeting that we did a few years ago, it was actually a fun meeting, a lot of friendly discussion where we all decided that the ACL and the IT band are most important. So, this is Stability 1. I'm just going to go real quick through this since Al already talked about it. Additional injury obviously happens, depending who you read, probably in about 85% or so of your ACLs. It's very rare that you find yourself just doing an ACL and if you do, you should ask yourself, did you miss anything? What we figured out through this pivot-shift testing is that if you have a medial meniscus tear or a lateral meniscus tear or anti-lateral corner injury as seen on MRI or a combination of the three, you have a high-grade pivot-shift and that is not true for your MCL and PLC sprains. We also looked at what ACL plus LET does as far as restoring rotatory aneloxity and both actually did a very good job. This is time zero data using the pivot app in the operating room. I just want to show you two quick cases. This is a professional soccer player. They had an ACL tear, sort of average-sized ACL. We always measure everything before surgery so there's no surprises. We usually don't use a notchplasty. They also had a posterior root tear. So this is a root equivalent tear that you could see there being just fixed with an all-inside suture as opposed to do a trans-osseous repair which we would do if it was completely off. But even a professional athlete, I would consider this and so far so good, they did well. Here's another athlete. She is a Division I soccer player and already had an ACL reconstruction. So in this case, ACL is failed, average-sized notch, and in this particular case, because of the huge instability, we added an LET. So there are cases where this should or could be done. They also had a ramp lesion which got fixed. So here are a few of my favorite things. Huge tunnels, big slopes, you know, missed roots or maybe ramp lesions where you could say they have occurred later through the instability or were missed at the first time. But those are all things that will happen to you in the revision setting. So slope, once it is over 12 degrees, we consider it. Currently only in the revisions, and I get lots and lots of emails asking, what would you do in a primary case with a 15-degree slope? And so I want to show you this image too. This is from Dr. Fu. On the left, you can see an anatomically placed ACL that has failed, although it was anatomic because most likely the notch was too small for this huge tunnel. And on the right, you can see two that have both made it, whereby the one on the bottom is obviously completely malplaced, but in a large notch, but it doesn't make a big difference. We've studied a lot the bony morphology, so we're talking obviously about the tibial slope, but there's more to it. There's a lot of changes on the femur between ACL patients and controls. We talked about the notch sign earlier. There's also an offset posteriorly. There's an angle by which the posterior condyle is offset from the shaft. And then there's coronal plane issues. All of these things are different between your ACL patient and your normal knee patient. So here are some rationales about osteotomy. Obviously there's a mechanical rationale, biologic, and then the ligament balancing, which is what we're talking about. The two different techniques, and I suppose you could also go below the tuberosity I described both from Leon, by Bertrand, by David, I currently use the one on the left, whereby we elevate the tubercle and then do an osteotomy through it. The one on the right that David described is technically quite challenging, but obviously very well done in his hands. I've done it a few times. It's really difficult. So indications would be recurrent instability in the revision setting, 12 degree or more slope, and a neutral leg coronal plane alignment. If there is a varus concomitant, then obviously you need to do a biplanar type of surgery. If the patient has hyperextension more than 10 degrees, I would caution not to do a slope osteotomy because you will increase the hyperextension quite a bit. A big varus deformity, you can't do a simple slope changing osteotomy either, and obviously osteoarthritis. Here's a study that was just accepted over at OGSM. Just a series of cases between Al and the Calgary group and us. So what we did is we've done 23, those are really complex patients. They all have two failed ACLs, and if you look at this, their slope was changed on average by about 10 degrees. The anterior tibial translation was reduced, but also know if you look at this picture on the left, they are fixed anteriorly subluxed, and you will never change this unless you change the slope. They had a pretty good Kuh score, they did have some re-operations, and three failures. So it's not failure free, but I would argue that in this type of patient population, that's a pretty good outcome. So I'm going to show you a case here at the end. This is somebody who had three previous ACL reconstructions, hamstring and allograft reconstructions, and they came in with a huge rotatory instability. You can see here, ACL is gone, you can also see the medial meniscus is gone, articular cartilage seems to be okay. They have a 23 degree slope, so I think after three failed ACLs, that's pretty clear cut, you're going to have to act on that. They had slightly enlarged tunnels, and they were also, if you will, semi-anatomic. I don't like staged surgeries too much, but in this case I did, because I wanted to see the compartment and see if they would be appropriate for a meniscus transplant, meaning is the articular cartilage good enough? And so it was. We did a staged osteotomy at first, changing the slope, and then in a second stage we did a meniscus transplantation and revision ACL. Again, I used an allograft, we can argue about that, but the reason I did this is because I wanted to avoid that semi-anatomic tunnel, so I went over the top, and the Achilles tendon is the best choice for that. And so here is basically the slope change, the tibia is reduced, and so far their knee is working out pretty well. You can see a slight bit of hyperextension compared to the other side, but nothing dramatic and nothing that the patient would complain about. And you can also see this is not your tightest knee that you've ever examined, there's certainly a Lachmann, there's an anterior drawer, and you can see here at most a gliding pivot shift. But again, this is a third failed case, so I think it's pretty good. So we talked about stability too, 200 patients done, 1,000 to go. If you're interested in collaborating with us, you can talk to Al and I afterwards. These are all the centers that are currently involved. And so in summary, I use lead currently only if it's in the stability trial, otherwise I don't. I use it in some revisions, I do the technique just as Al has shown. HTO, you always want to hear about degrees and at what angles to fix things, so in revision cases I'm quite aggressive, especially if I do meniscus transplants, so somewhere between three to six degrees or so of various, I will act on this. The deflection osteotomy, I currently use the number 12, and it has to be in a revision setting, I haven't done it in a primary. And I do meniscus transplants if the patient has a meniscectomy knee and it's painful in that particular compartment. So a failed ACL always has high-grade rotator instability that is a fact, so you have to act on this. Fix concomitant pathology, if there's nothing else to fix then you can do a let, or you can augment it because the failure rate is reduced as you've seen from Get Good study in hamstrings. I don't think it'll matter in quadriceps and patella tendon, but we'll find out in a few years. HTO is a really powerful tool in select patients, so careful with your indications. Thank you very much.

ACL surgery

graft choice

tunnel malplacement

biological factors

slope osteotomy