All right, next we'd like to invite up to the stage Dr. Mike Zichilli from Northwell Lenox Hill to come up and talk about when to graft, when to stage in terms of revision ACL reconstruction. Thanks everybody for having us. My disclosures are available on the website. Second disclosure, in the setting of this discussion, it's important to understand the frame of reference. We're grafting in about 10 to 15% of our revision ACLs. This is not by any means every patient, and you need to keep that in mind as we go forward. So which cases are we discussing? So basically, when we're dealing with a revision ACL setting, I want to map out my anatomic location and look at my old tunnels. I want an anatomic position for my new tunnels. If I have anything that compromises my position, anything that compromises fixation, this is the case I'm concerned with. And unfortunately, we know that these tunnel problems are common, anywhere from 40 to 80% of all revision ACLs having problems with tunnel position. And yet, we're only grafting 10% of them. So let's look a little bit closer at that. Why is that? Where is that gap coming from? Well, the good news of failed primary ACL, when it's done poorly, is easy to fix. So we can largely ignore many of these. And so that 85% to 90% that we don't need to deal with the tunnel is a healthy and easy fix. New apertures and tunnels, about half of femurs. Tibia is a little bit more concerning and more oftentimes a problem. 70%, 80% tibia tunnels sometimes cause a problem with our next stage procedure. So I want to frame this. This is not so much the discussion about whether to graft or not. But in the setting of these tunnels, ideally, how should we graft? And then a little bit of a dose of reality after we talk about this scientific ideal. So some absolute truths, I think, that most of us can agree on. One revision is obviously better than multiple revisions. We know that with every subsequent revision, your risk of a re-tear, as Adnan brought up earlier, goes up 25 times as high on the fourth ACL. So your first revision is your best chance for a good outcome in these patients. Second truth, autografts are better. I will die on that sword. We know from the MARS group, as we get more and more complicated, more and more failure, we trend more towards autografts. Why? We must know something, right? And if we look at those authors, we know that allograft re-rupture is about twice as high as autograft re-rupture in the MARS cohort. So I think that's fairly clear. We also see functional outcome benefits to the autograft that favor that over allograft. And this is not the only evidence we have. Met analysis of 32 studies and revisions looking at autograft versus allograft showed superior stability and fewer complications re-operations in our autograft groups. If we look at the Swedish studies, this is the registry, a very large study, and allografts were an independent negative predictor for COUS in both subscales. And if we look at that on a larger scale in this multivariate regression, it's one of only two predictive factors for that decreased outcome. So we know that we want to use an autograft, and we know that we really want to do it best the first time. Unfortunately, autografts have a finite size. We have limited ability to fill or correct those holes. So that's really where the trouble comes in. And in fact, you know, most of us have learned numbers somewhere between 12, 13, 14 millimeters, but some recent work out of Ohio State has looked at this a little bit closer in single stage revisions. And I think it draws attention to maybe that number where we start seeing increased failure, maybe even lower. And I think of this similar to some of Tokich's work with the shoulder of like, what is this critical loss? And this is just a little doodle I did for my residents to try to explain it's not even just the tunnel. Really, what I care about most is our aperture. So even if I can fill the tunnel, if the aperture is wide, no matter how I adjust my autograft, I'm potentially posteriorizing that graft within the ACL, within the knee. And that really functionally is the same as putting my tunnel in the wrong spot. So any sort of posterior dilation or functional posteriorization of my graft is an aperture problem and I'm going to stage that almost all the time. So finally, the last truth is that comorbid injuries are common. And similar to some of the other people who have been up here, I'm obviously someone I believe very much in our bony issues and our meniscal and cartilage issues. And so addressing those is extremely important if we're looking at maximizing that first best chance at a good outcome. So these are all variables we consider in the setting of a revision ACL. And so a bunch that link directly to ACL failure, a bunch that link to bone loss, and some in between. And when I look at this huge list, there's only about four that don't matter to me for my surgical plan. The whole rest of that list is something that's going to inform the way I approach my revision. And so what better way to deal with that than to work with more knowledge? And we've discussed with the cartilage, inside, during my scope, I'm going to have much more information than I'm going to have from an MRI alone. So this is a perfect example, 31 active duty soldier. The tunnel looks anterior. This looks like something I could single stage. I got a flipped, failed prior bucket handle, but it looks like decent quality. So single stage, right? When we get into the knee, and I look at this bucket handle, and I can't fix that. We know that meniscus tears are going to increase our risk for failure. So what I'm going to do here, I'll go ahead and bone graft my tunnels, and then be able to come back after it's healed, and approach this in a comprehensive manner, do my meniscus and my ACL revision all at once. Similar to these associated injuries. So we know meniscus tears can increase strain on the ACL. We know that it can increase force on our joint and decrease long-term outcomes. And that's not the only morbidity that a stage procedure allows me to address. Varus alignment, tibial slope, the anterolateral complex, all this information is stuff I can get during my staging. So staging allows me to address comprehensive care, whether it's bony, cartilage, and then have a clean slate starting with my revision for that best chance. Results of staging speak for themselves. If we look at this systematic review, basically for all factors, two-stage outperforms single stage. So when in doubt, stage. If you have any questions, stage. That being said, not all patients are the same. In the military, it's easy for me to tell people to take six months off. In the civilian population, my bankers, they don't want to listen to me. So we talk about shared decision-making, and the things that go into that, time, resources, willingness, that's all great. But shared decision-making oftentimes is patient decision-making. And so when you know that staging is oftentimes the best answer, but you can't, how do you deal with that? So we just need answers to modify that. And so biomechanically, we have some pretty good research about this. My preferred technique is bone dowels. This is shown biomechanically in cadaver studies to be the closest thing to a primary ACL for stability. It's fairly plug-and-play, no pun intended, in the femur. On the tibial side, I think it can be a little bit more challenging if you're going to drill at the same time. Some work from Jason Dragoo utilizing some suture anchor fixation or suture stabilization of your dowel, I think, can be very helpful. And also, occasionally, we'll switch that to a knotless anchor to assist. And then finally, if all else fails, we're dealing with a large tibial tunnel or a large femoral tunnel that's huge. We know that the autograft is best, but the patient wants single stage, you know, work out of pit. Doing an over-the-top, a large calcaneal bone block in the tibia can fix a lot of problems. So thank you. Thank you.

ACL reconstruction

grafting

revision ACL

tunnel position

fixation issues