»» We'll open it up to questions. We should have about seven or eight minutes for questions. Dr. Stewart has the first question. »» First of all, thanks to our expert surgeons, but also very eloquent speakers that stayed on time. So now we have a little room for questions. Rachel, why do a distal femoral opening wedge osteotomy since most of our corrections are small and a medial closing wedge osteotomy with a periarticular locking plate is very stable, immediate range of motion, weight bearing, why hassle with opening up the distal lateral femur? »» Well, thank you for the question. What I really love about that question is you didn't mention the tibia at all, which clearly means that we're only focusing on the femur for the valgus knee and debate has been won. So thank you for that. I'd love your question. So it's a question I ask myself because I was trained to do lateral opening wedge distal femoral osteotomy. So as I entered practice that was the comfortable approach for me to approach these patients. But I do think the argument for medial closing wedge is certainly there. The biggest challenges with closing wedge anywhere you go is precision. So with now some of the custom guides and planning you can get a bit more precise. But it is a little bit harder to dial in the exact amount of wedge that you're taking out versus with an opening it can be a little bit easier to get more precise. I think we all probably are not as precise, or at least I know I'm not as precise as I'd like to be. But I think it's more difficult with a closing than an opening. But I would agree. I think for corrections of under 10 degrees, perhaps under 12 degrees, especially in our patients who are going to want to wait there immediately, a closing wedge is going to be a better option. The outcomes are great no matter which way you go. But I think that it's something that we have to become more familiar with. Many of us have trained classically with a lateral opening wedge approach. So that's just more familiar for us. That's good stuff. So I have a question for the whole panel really, but really for Anil and Rachel. So we talk a lot about femoral and tibial and what it's going to do to the joint line and the joint line obliquity. And I think that's important. And I think the tendency is if it's varus do it on the tibia, if it's valgus do it on the femur. I think we kind of get that reflex. But how do you assess joint line obliquity? I think that that's something that I'm very sensitive to. But I still struggle to a certain extent to predict what it's going to be post-op because you're changing the position of the leg and they're going to bring the leg back to neutral. So how do you make that assessment, Anil? You go first. Well, if we're doing valgus knees and small deformities, it's usually not that big of a deal. The big of a deal is, as Dr. Lyle has actually pointed out, is your soft tissue laxity. And do you have an intra-articular deformity that you can have to assess with your soft tissue laxity? Another line is, although it's a bone cut, it's still a soft tissue operation. So that's where you can really get a runaway knee. So I still assess the knee in 0 and 30 degrees on both knees and see how my soft tissues are playing a role. And then I'll adjust my deformity based off, or my correction based off that. Because it's not just measuring the joint line obliquity angle, which is important, it's also looking at soft tissues. Now you have a ton of experience with this, but are there objective numbers you look at? Like proximal tibial, distal femoral angle? How are you assessing joint line congruence angle in terms of that joint laxity? I mean, the joint line congruence angle, you just divide it by two. You can wrap your brain around it really hard, and I don't think we really have the answer. But I would say in a more unstable knee, obviously you're going to be very cautious about the amount of correction that you do. Rachel? Not much more to add to that. I mean, it's a great answer. I think we can get very specific, especially with CT scan and software to measure both pre-op and post-op and assess our deformities, assess our angles and determine a game plan. But with those valgus knees, particularly higher degrees of valgus, you're going to have stretched MCL, tight lateral side. And it is a soft tissue component that the CT scans or any x-ray or whatever, any objective measure can't measure. So I think it's more difficult and it's interesting. That's why I showed that x-ray from Travis, but the patient's doing well. So a lot of patients can accept a degree of joint line obliquity and not have a clinical detriment. And so I think we can get very, you know, one of my patients called me a knee nerd the other day. And I think we can get very... That's a compliment, by the way. I took it as a big time compliment. We can get very nerdy about this and critique ourselves with measurements all day long, but it's about how the patient's functioning at the end of the day. One of my biggest rules is, and it's kind of came from total knee literature from Mayo, is when they figured out that it's not just alignment that predicts total knee outcomes, it's really soft tissue balancing. And just like if you overcorrect a varus knee and you keep that medial side tight, you know, I do a lot of medial releases on varus knees. And it's, you know, so understanding how that soft tissue balancing plays is really the future of osteotomy. And I'm not saying I know the answer, but I know what I've learned from total knee replacement and I apply those same principles. Mike, you have a question? Yeah, just very quickly, I think for Al and Volker. So educate all of us in the room on when we pull the trigger to do a tibial slope-reducing osteotomy in the setting of revision ACL, and if we decide to do it, is it a single stage or a two-stage operation? I'll have a stab at that first. It's a great question. It's always the question that, you know, that people want to know, you know, when should we do this procedure? Because it's a big operation. But I mean, I think the more you do, I think the more you realize that actually it's maybe it's not as big an operation as we once thought, and it's a very effective operation at reducing anterior translation and reducing your strain on your graft. So for me, if it's a first-time revision and the slope is, let's say it's greater than 12 degrees, but the, you know, the ACL reconstruction that was done first time wasn't done that brilliantly, then if there's things that I can do to improve the original ACL reconstruction plus add lateral extraticular tenodesis, I'll probably go down that route rather than pulling the trigger on an osteotomy. If it's not a sort of second, third revision and, you know, I'm just going to do the same thing as what's been done before, I want to change it up, I want to do something differently, and so then that's where I'll think about an osteotomy. I love it when they have fixed flexion deformity because you can really improve their extension. If they have greater than 12 degrees on a short film, if they have increased anterior translation greater than 10 millimeters on a sagittal, sort of lateral monopedal weight-bearing radiograph, you're not going to be able to control that with a soft tissue procedure. Bone will dictate, and so then that's when I'll add in the anterior closing wedge. In terms of staging, if I can do it all in one go, I will. If I can't, it's not a bad option because you can take the bone wedge out, you can use that for autologous bone grafting of your tunnels, and particularly if you're going to do it in a staged fashion, that's when maybe a TTO is not a bad option. If you're going to do it all in one go, then doing a super-tubicle, leaving the tubicle on, and it basically doesn't have any issues with your rehabilitation, then you can do the revision at the same stage. Mike, I think every one of your ACL patients has an increased slope, and we've shown that. Many people have shown this. This is pretty clear. But in addition to the comment that was made right here at this microphone, when you have an ACL-deficient knee, over years and years, that slope increases. You may want to believe it. You may not want to believe it. There's very little out there. Lars Engebretsen studied it a little bit. I think that's the only paper. But you see it on your patients. Just go measure them. When they come in and they have bilateral ACLs, one has failed, one is intact, and this has gone on for years, you take bilateral lower leg, full leg, full-length TBR x-rays and weight-bearing, you will realize that. I don't know that there's necessarily a magic number, but when you're asking, I think you want to hear from us, would you consider this in a primary ACL? Yes. Here's the case I would consider this in. Somebody who's already failed their contralateral side, they have a tibial slope-changed osteotomy on the contralateral side, and now the ipsilateral is tearing, and they have an 18-degree slope. So I don't know that you all like numbers, but 18, I think, is the number for a primary or a first revision, and 12. If you look at your failed ACLs, whether you do it in a first or second failed, a second failed ACL, show me one that has a slope less than 12. They all do. And I think it's pretty clear you probably ought to act on this. Not sure we're going on primaries yet, but eventually. It's like glenoid bone loss with shoulder instability. I think there's some parallels there. The interesting thing from our data is that most of the patients that were in our series were second and third revisions, and their patient-reported outcomes aren't that great. So there is an argument to actually be doing this at a much earlier stage, and probably get a much better result, and probably save the ACL. But you're dealing with risk as well. So you've got to talk to the patient. You've got to understand what their motives are, what do they want to get back to. It's a shared decision-making in terms of whether or not you're going to do this osteotomy. I think we have time for one more question. Travis? There we go. That actually is a good plug for the ICL on Saturday, worst day in the OR, and that's like one of many. I have lots more, so come. My question is, I screwed that one up because I did a single osteotomy. The majority of the deformity, as Philip Lobenhofer taught me, a mentor of mine in osteotomy, fixed it where the deformity is. So I fixed it where the deformity is. The problem is the deformity is on both sides. So my question for you all is, what's your threshold to doing distal femoral and proximal tibia osteotomy in the same setting? And where do you say, I think I can get away with just doing one, understanding the morbidity of that operation? Who wants to tackle it? I think just quickly, I mean, I would say understanding osteotomy is a natural evolution. When you first start, you start with opening wedge single cuts. Then you start doing closing wedge cuts. Then you start doing slope correction cuts. And then that's how you evolve teaching with osteotomy. And so I think in terms of double level, you know, it was like two osteotomies seemed crazy to me. But I saw so many joint line obliquities when I was younger. And I realized that in terms of soft tissue trauma to the patient, two osteotomies is better than corrupting the joint line with one osteotomy. So Armando taught me that a lot, is that my thresholds change a lot to do more double level osteotomies. And so I think my patients tolerate much better than doing bigger corrections with one osteotomy. Yeah. I think if you look at our series of complications, the number one reason for having a hinge fracture with a medial opening wedge, HTO, is a correction greater than 11 millimeters. So if you're getting up into larger corrections, and then we're looking at an MBTA, I don't want to go over sort of 93, 94 degrees. To say that it's going to be 92 degrees, that's all you're accepting on a fluoroscopy image and the OR is probably not realistic. So that's maybe where PSI and stuff like that might be able to help. But in those scenarios, having a double level where you're basically splitting the correction across two bones, reducing the correction, reducing your risk of hinge fracture, is actually probably reducing your risk of complications than actually just doing a single correction. So certainly my threshold for doing DLOs is actually, is definitely reduced and finding it very, very straightforward. The only thing I would add is there is computer simulation now available for these very complex cases with large deformities. And you can preoperatively analyze joint line obliquity, medial and lateral compartment pressures, et cetera, and do the surgery on the computer. Granted, it's static. It's based off digital radiographs. But in those cases, it might be helpful, and it tells you the amount of correction on either side, the correct joint line obliquity, pressure, force distribution. So consider that in these very complex cases. Great. Well, thank you, everybody. That was a great session. Thank you, Dr. Stewart, for moderating. Thank you to our speakers. And I appreciate it.

orthopedic surgery procedures

distal femoral opening wedge osteotomy

joint line obliquity assessment

osteotomy approaches

soft tissue balancing