Starting at 10 a.m. on the dot, we're going to be precise military timing for the course over the next two days, so let's see how long that lasts. I know, we've got Christian Clay here, so I don't know, we may be here till Sunday. I'd just like to welcome you all to, this is the third edition of the AOSM-ISACOS combined osteotomy course. And with that, I would like to thank both the office from AOSM as well as ISACOS team it's a huge effort to put a course like this together. We really do have a huge amount of delegates, it's a sell-out course, we've got an all-star faculty and I think it's going to be a fantastic two days and we're excited to be all together. We have purposely made this room much smaller. We can't always open this wall and extend way back over there and all that does is, what we really want to do is condense everyone together because this is all about discussion. This meeting is all about discussion as best we possibly can and therefore we want to be in an intimate setting to be able to do that. So over the course of the two days, particularly for today, we're going to have some lectures but then we'll be doing a lot of case-based discussions and really the success of the meeting is going to be really based upon your interaction with each other, with faculty and the more information that you can partake and get involved, I think, the more everyone will get out of it and I know I love helping run these courses because I always learn something from not only from the co-faculty but also from all of the delegates. You've always got something that we can offer into the mix and I'm sure today and tomorrow will be no different. So I'm going to hand over to Liza. She's got a few comments to make as well. Liza? I also have pushed for an Asiatomy course when I was on the Education Committee of AOSSM for as long as I can remember. I think it's very much not as much as I'd like to see in our education programs for all of you residents, fellowships and former residents know. So I'm happy to be here. I thank my co-chairs. The three of us represent beauty, brawn and brains. I'll leave it to you as to which is which and I just want you to know we're a sold-out course. We have 51 attendants representing 17 countries and five continents. Approximately one-third are international. Approximately two-thirds are from the United States which as much as I love the international faculty you have to understand that in the United States I think we need to know more about Asiatomy so I'm happy to see our fellow United States participants. And the faculty represents four different continents and so that's really a great testimony to the AOSSM and ISACIS and we really owe a lot to ISACIS to try and bring this collaboration between AOSSM and ISACIS together. So without further ado. Perfect. So just some housekeeping regarding the first session this morning. We are gonna be doing, we're gonna have four lectures and then we're gonna be getting into some case-based discussion. The cases we're gonna be putting out to the floor and then what I do want is the tables so the tables at the back we're gonna split you down the middle so there's three on each side so the second table from the back can turn around and then it essentially creates a round table so you're gonna do that on every other table if that makes sense. So you've got six, six, six. You're gonna have a member of faculty at each table and so we're gonna be presenting the case, you will discuss it, okay? And then we will discuss as a group what everyone thinks. Not every table will be asked about every single case but ultimately we just want lots of discussion within your own small groups and then bringing that information forward to the larger group as a whole, okay? And that's the goal over the course of today. Over lunch we'll be having a lunchtime symposium I think today and so thank you very much to all of our industry supporters for this meeting. We couldn't run a meeting like this without our industry partners so thank you very much for you guys for being here. And then this afternoon we'll be doing a very similar format with a few lectures and then again some case-based discussion and then this evening, this evening should be a really fun opportunity. We're gonna have beer and pizza over at Complications Corner so all the faculty have brought their worst complications and you guys as delegates, if you wanna bring your complication up to the floor as well, you're more than welcome to submit it. It really should be like an opportunity to confess all and I certainly find that I learn so much from those types of discussions because when we do make a mistake, there's no question we can always make up for it and learn from it. So with that, I think we'll get on with this morning's session. So both Liza and I will be moderating this session and first up is our co-chair, Rob LaPrade. Really takes no introduction. Rob is gonna give us an overview of osteotomy basics and this is really gonna set the stall out for the rest of the course. Rob. Thank you, Alan. Thanks to everybody for coming and a special thanks to Julie for putting up with the three of us and putting this together. We kept changing our minds at different points in time and doing different things so it looks like we've got a great agenda. The course keeps getting bigger over time so I just wanted to go through the basics so I guess I'm not the brains when we're talking about what was going on here. Liza was talking about my disclosures, nothing really relevant to this. So number one thing with osteotomies, those of us who see a lot of these patients, patient selection is the key. You really have to understand what the issue is. If it's a ligament issue with an arthritis issue, you have to figure out if it's pain or instability to make your right decision. You have to understand both the coronal plane and sagittal plane portions of this because if you don't, you could be making mistakes and making somebody worse and then you have to ensure that you have a complete physical exam and radiologic exam. And surgeries are easy, they really are easy, but patient selection is hard and it's a key to making sure we make the right decisions. So as part of the coronal plane workup, I'd strongly encourage you to look at unloaded braces. It can screen who can benefit from osteotomies and I found out if the unloaded brace doesn't work, usually the osteotomy doesn't work. When the unloaded brace works, the patients almost always come to you and say, I hate this brace, it takes my pain away, I want the surgery. So you're not presenting to them right away, hey, you need an osteotomy, I'm gonna break your tibia and you're gonna be on crutches for a certain period of time and they're like, what do you wanna do? So if you can actually help them to buy into the process and decide that that's what they need, it's a good way and I found out that it helps me to almost always choose the right patients for osteotomies. It's also important to look at the sagittal plane alignment and this is difficult because these are almost always younger patients where we're considering sagittal plane abnormalities. So they're often second opinions, especially in my practice where they've been referred in, where ACL number five, ACL number six and nobody's even thought about looking at their slope. So we'll discuss the peer review literature where we say that there's a much higher risk when your slope is more than 12, that your ACL's gonna fail at a certain period of time, we can go through that. For PCLs, if they've got a flat slope, it's an issue. But the one that seems to hit the key most of the time for us is I ask them if they've ever had experience with a dog ACL surgery and almost everybody has some experience, they heard of a neighbor or somebody that had a dog ACL surgery and veterinarians figured out in the 1990s that ACL surgeries all failed in dogs because of their slope. So since that point in time, they've been doing tibial leveling osteotomy. So it's the same thing. Some people get upset when you tell them they have a dog knee but it helps them to understand what's going on and that the slope is a key part of understanding revision ACLs. And you should get basic radiographs and everyone to help make your decision. I'll get AP and lateral with markers so we can go back and check the magnification. Look at the Rosenberg view to check their joint space because if you're just looking at a plain AP, like on this case here in a younger patient, you can miss how much arthritis they have. Also the sunrise view because the sunrise view is a postgraduate way to look at the amount of medial compartment or lateral compartment osteophytes. So you may not see a lot of joint space narrowing but you can see the osteophytes, you can look at that. And of course, optimally, we should be getting long leg x-rays in everybody and I do this on all of my new patients, we get long leg x-rays. Then you have to look at the special radiographs, mainly for chronic ligament issues. You can look at getting long leg tibia x-rays to check their slope. If you have them flexed, you can get ACL stress radiographs also and determine the side-to-side difference in anterior tibial translation. The more slope there is, the more likely they're going to slide more. We can get PCL stress radiographs also. Most of the time when you see a lot of increased posterior tibial translation, it's gonna be because of a flat slope, not an increased slope. And then we can get stress radiographs also to help us in determining if it's a medial or lateral sided injury. For osteoarthritis, I think it's essential we have long leg alignment x-rays. And I have seen patients that have been sent to me that didn't have a long leg x-ray, had an osteotomy and then they're shifted way over into the ipsilateral compartment where they do miserably and it's really hard to undo an osteotomy at that point in time. Not to say you can't do it, but it makes it a lot harder. So get the long leg x-rays so you validate if they're truly invarious or valgus if that's an issue. And then get the Rosenberg view to look at the amount of joint space narrowing. And then I like to get MRIs on all these patients just to make sure that their contralateral compartment has sufficient articular cartilage and meniscus. If I'm gonna shift things over and the unloaded brachios are doing better, that I'm doing the osteotomy for a patient that's gonna have a long enough life for their knee to be able to benefit from it. And then calculation of coronal amounts. Traditionally in the past, we used to look at measuring them out on paper. But you can do it digitally and do it very easily. And I encourage you to look at that. There's multiple different ways and it's all based on geometry. And probably every single way we look at it is equal. So what I like to do is for when we're looking at correction from a varus knee and it's not a ligament issue, it's arthritis, we're trying to shoot for the apex of the lateral tibial eminence. Some people will say 62% Fujisawa's point or the middle of the knee. I like to go for the apex. And the same thing if we're looking for a correction of valgus alignment, we're looking for the apex of the medial tibial eminence. Then you can draw the lines from the center of the hip through that point and the center of the talus through that point and that'll give you your correction angle. You can measure the length of your proposed osteotomy and then measure that along there and you can look at what your amount of opening would be. Another way you can do it that works equally as well, and I've done it on these radiographs, just measure the angle there. And it's usually one degree is equal to one millimeter of opening. So either one of those, in this case it's nine and I measured it both with just measuring the length of the osteotomy along the calculated angle and just measuring the angle itself. And they're both within 0.4 millimeters. So whatever you do, make sure you use it consistently and then check your radiographs afterwards and see if you need to change your technique. We try to get long leg x-rays at three months and everybody just saw, I remember, if I've corrected things and we're trying to make sure it's getting exactly where we want. For sagittal plane correction, Mark Miller did this study where he found out that one degree is one millimeter. The problem is that that relies on making sure that your tibia is correct and you've got the right magnification. And if you're, that's for super tubercle osteotomy. And if you're taking off the tibial tubercle to do the closing wedge osteotomy, it's 0.8 millimeter per degree. But I also encourage you to use geometry and measure it so you end up with what you want. The general feeling is we're shooting for a decrease in the slope in the literature between four and six degrees. Andy Bernardson's done some studies with that, looking at the amount of force on the ACL and that seems to fit with the biomechanical data. And for PCLs, we're looking at trying to increase the slope to between eight and nine degrees to give us the best outcomes. Special issues to consider, I think it's important to recognize this. People just don't need coronal plane and sagittal plane alignment corrections. You have to make sure you're looking at both. So almost every osteotomy should be biplanar. If you see in that radiograph there and also in the MRI, when somebody has a post-meniscectomy knee, they're going to wear out the posterior aspect of their knee. So you don't want to increase the slope in those patients because you're putting more stress on the back portion of the cartilage. And that's why in their standing AP, you can see a joint space, whereas in the Rosenberg view, they can be bone on bone. So just think about that when you're looking at your basic calculations for the simple ones so that you can change the slope appropriately for these patients and just don't change the coronal plane alignment. Post-operative rehabilitation, it's all over the board. There's no consensus on this. It depends on what type of plate you use and what type of fixation you have. But it's important to make sure that you start range of motion right away and to work with your physical therapist on choosing the right rehabilitation protocol. The whole goal is to make sure we don't have a lot of quads atrophy because in these arthritic patients, when they start putting weight on it, they're going to overload it and have increased problems with pain and swelling if their quads have atrophied too much and they won't benefit from the surgery right away. The other issue is return to sports and return to work issues. The most common question we get is how long can I wait before I can drive, right? And if it's the right side, it's an issue if they don't have a clutch. The left side is usually seven to 10 days once they have appropriate leg control. Do they have a desk job? Are they traveling a lot? Will they have to worry about getting a DVT? Do they have manual labor jobs? For some reason, I seem to be operating a lot of nurses and usually nurses take four to five months to get back before they feel that they can stand up all day. For sports, we want them to have appropriate strength to make sure that they don't overload the joint. So we're looking at quadriceps limb symmetry index of 85% and we'll test everybody to validate that. I will say that most of my patients do not hit that at six months. They need it further down the road before they have appropriate strength to get back to sports. So you should consider strength testing in your athletes. So in summary, it's important to ensure a good physical exam and x-ray workup so you choose the right patient. Look at coronal and sagittal plane correction in almost every single patient. We need to look at this. And with proper patient selection, these patients do amazingly well and you can get good outcomes. Thank you. Our next talk will be the first of a great international faculty. It'll be Christian Clay from Hanover, Germany and he will talk to us about deformity analysis using software to achieve accurate correction. Okay, just a, perfect, just need the. And maybe as he's setting up, you can tell us a little bit about your background, Christian. Yeah, my background. So, yeah, my name is Christian, Christian Clay. I'm a professor at the University of Washington and my name is Christian, Christian Clay. I'm, as mentioned, from Hanover, Germany. And obviously, first at hand, I'd like to thank you for the invitation and the opportunity to speak here. So, yeah, obviously being from Europe, and you will see Matt afterwards, we have quite a tradition there of doing osteotomies about the knee. And well, we, I guess, traditionally have done more of those. And osteotomy, anyhow, even in Europe, we've had its hard times when it had a bit of a pushback in the 70s due to the rise of arthroplasty. But obviously, as we've learned over the last years, we haven't found the holy grail with arthroplasty. It's rather that we've also encountered some issues with that. And it just doesn't fit for everybody. And nonetheless, total knee joint is a great surgery in the right patient, but it needs to be the right patient. And we've just recently had publications such as in the NHS, and I equally do work in London, in the United Kingdom, not Ontario, and in the London, the London, London. So, and actually, in the NHS, which runs the biggest arthroplasty register in the world, we had a publication 2017 from Bayliss. And this publication actually has shown propensitory matched 55,000 knee joints that the revision rate, especially for or particularly for male patients under the age of 60, is actually not acceptable and rises up to 40% in the first five years, which is obviously devastating. And particularly for that subgroup of patients, obviously, we need to seek for answers. And I guess we have answers if we just look back to where we have all started with and where did we come from. And that makes things then easier. But enough said, I guess. We just go into the planning of an osteotomy. And we've already heard about this rule of thumb, one millimeter goes by one degree. And obviously, that's always tricky. I mean, you can say that, but it's not quite precise. And obviously, we debate about precision here. And it cannot be precise because when we want to translate angles into metrics, then we run into issues when we have patients with different height. So it equally has to count for Maria as for Shaquille O'Neal. And obviously, there is a bias in that and things are different. Disclosures, once again, I have actually royalties from Nuclip and I'm a consultant surgeon for Nuclip. So these are the royalties. Now, when it comes to long leg standing films, obviously, it's not only important to have some and you need to have X-rays, long leg standing films for planning an osteotomy, but needs to have the right orientation. And here it is more important actually to have, this is one of such an example where I just sent a patient back to the radiographer that came back with this image here. And obviously, when you just resend and redo the image, you can see that the coronal alignment changes completely just by the rotation profile. So you cannot plan on such a mal-rotated image and what is important there is that you have the patella somewhere in the middle, but actually that's the most mobile bone at that area. So I rather look at the coverage of the fibular head of one third and that the condyles look straight at you and not square curved, okay? So the osteotomy has to somewhat be at the side of deformity. Well, that's obvious, I guess. When you have a mal-alignment, you wanna correct the mal-alignment and not anything else. So you need to actually find where the mal-alignment is. That's what you have those x-rays for and then you need to measure and we call this process analysis. So you need an analysis of your mal-alignment and I was, well, in our own unit in Hanover in 2014, we made some 340 osteotomies roughly and we found that 20% of the mal-alignments were originated in the femur. Whereas we only back then based on our practice that we had the 1% of our osteotomies at the femur because the tibia was so convenient and it was just the workhorse. And so checking the origin of deformity in our own practice, we have to confess that we treated 19% of our patients at the wrong bone, which is obviously not great. If you're a trauma guy and the patient comes with a left wrist fracture and you treat the right ankle, it's probably not a good idea. So, and this is actually what we've done here. So we had to kind of retailer our principles. And as I said, the first thing on this path is actually analysis and that's key. So analysis of the deformity and this is what we have to thank Dror Paley for. So the nomenclature and the analysis in a systematic approach and that's very important. So first thing we need to defy is joint centers. And for both long bones, femur and tibia, there is two joint centers, one proximal and one distal one, it's quite simple. And then the first thing is we go for the proximal of the femur, which is the center of the femoral head and this is spherical structure on a 2D image is a sphere. Finding the center of a sphere is quite easy. So that's the proximal joint center of the femur. Let's go to the distal joint center of the femur. And you see all these blue dots here lined up quite somewhere all in the middle. And regardless what kind of reference you take in a properly aligned and rotated image, you can take the outer margin of the bone, you can even take the mantle of the skin, you can take the roof of the notch. Regardless what you do, actually just be consistent in what you do and do it all the time the same. You see that these dots roughly line up in one line. So it's actually, it doesn't really play a role. Me personally, I take the roof of the notch. Then you go to the proximal center of the tibia and I take the area in between the spines. And then you go to the distal joint center of the tibia and there I refer to the center of the talus. So now as we have two joint centers for each long bone, we define joint lines. And the joint line, the distal joint line of the femur is actually the connection of the most distal points of the condyles. And for the tibia, it's the connection of the subchondral sclerosis. So we have now actually joint centers and joint lines. The next thing that we need is axes. And an axis is actually, it could be anatomic or mechanical for both long bones. So the anatomic axis is nothing else but the best reproduction of the shaft axis. And it looks like this. So you, somewhere close to the proximal and distal part of the diaphysis, you just medialize the diameter there and then you draw a line in between those and you have the best reproduction of the shaft axis. Well, for the tibia, actually the mechanical and anatomical axis don't really differ, but for the femur it does. And so this is why we need to know what kind of axis we need and what we look at. So we don't need the anatomic axis that I just described to you. We need the mechanical axes. And those axes actually are nothing else but the connection of the proximal and distal joint center. This is why we divide them prior, okay? So you just take the proximal and distal joint center and connect them. And there you have the mechanical axis of each long bone. And these ones are the ones that we are interested in. And if you look at it, once again, for the tibia, well, there is not much of a difference. But for the femur, there is one due to the femoral neck. So you always need to remember, you need to mark out your joint centers, and then you connect those, and then you have your mechanical axes. Now, in between your mechanical axis and your joint line, you will form angles. And these are angles that are very important. What equally is important is another axis, and that's the mechanical leg axis. Well, it is described as Mikulich line, but Mikulich, obviously, here is hard to pronounce, so we call it mechanical axis. This is the original thesis paper from Johan Mikulich himself. And it describes individual shape differences at the femur and the tibia of men, and obviously, equally, of women, with special regards to the static of the knee joint. That's himself. The quality of this publication is insane. Unfortunately, still only in German, and Matt urges me all the time to translate that. And well, at least for this little part, I've done that. So this is all in German, but here's the English version. So typically, the knee base is not perpendicular to the mechanical femoral axis, but forms an outwardly open angle ranging from 89 to 85 degrees. So this is the first ever description of the mechanical lateral distal femur angle, MLDFA, 150 years ago. Forgotten. Nobody looked at that anymore. It's really a shame. It's embarrassing. And hypothesizing that the alternating angle at the tibial side is actually the complement of this, he hypothesized that the lateral proximal tibia angle is somewhat 91 till 95. And if you translate that to the medial side, this is 85 till 90. So this is the standard deviation that you have for the MPTA. Actually, he described all that before. But this is new. This is the nomenclature about all of that. So Dror-Paley introduced this, and actually, that describes nothing else that Johan Mikulic told us 150 years earlier. But anyhow, he brought this nomenclature that, first at hand, we need to decide whether we speak about mechanical or anatomical axes. And obviously, we look at the mechanical. So we just use this little m as the description for that. And then it's all medial or lateral, proximal or distally, femoral or tibial, and then a for angle. As simple as that. And by definition, we take the lateral distal femoral angle and the medial proximal tibia angle. And now, obviously, you may think, well, that's difficult. Is it like, what is it? 87, 80, what? You don't really have to remember that. You just need to know that the Mikulic line, the mechanical leg axis, goes somewhere close through the center of the knee, passes at the medial spine with a bit of a medial axis deviation. But let's say we neglect that for the moment. And the knee baseline actually has an incline of 3 degrees to the inner of the knee joint. And then, obviously, you come to 87, 87 for each of those angles. So now we have the analysis of the malalignment. And that's obviously key. Because now you know the first time ever, where is my malalignment based on these angles. And if you have now your malalignment, you can plan how to correct that. So there is this method from Duckdale and Noyes. And we have seen that. And obviously, you have your Mikulic line. And you draw a virtual Mikulic line. And then you just draw another line, which intersects at your prospective post-operative intersection point. And then you can measure the angle in between. Well, technically, that's not bad. Geometrically, it's actually wrong. Because this is not the hinge point. And this is not where the action occurs. The action occurs, obviously, at the hinge. And the hinge is somewhere at the upper part of the fibular head connecting to the tibia in the proximal tip fit. So we have to bring this somewhat to our hinge point in order to make it correct. And it is this planning according Mianzi that allows us to do so. And in fact, Mianzi wasn't really the guy who came up with it. It was Rolly Jacob's method. And Rolly Jacob urged Mianzi, who was working as a fellow in his department, to publish on this. And in fact, this is the only thing that Mianzi ever published. But his name is strongly connected to that. And obviously, for some reason, because he published on it. So now let's go for such a planning as an example for the HTO. So first thing we need to do is we need to find our Mikulic line in order to know whether we have a varus or a valgus, a bolag or a knock-knee deformity. So then we draw a virtual Mikulic line, as we've done in the Darkdale noise planning. But then we change the perspective. Now everything becomes different. So because what you have to do now is you need to become the hinge. You are all hinges. And this is of crucial importance, because when you don't change your perspective, you forget what kind of lines you have to draw now. But it is very easy when you place yourself above the hinge point, and then you look to the point where your ankle joint is right now and where you want it to be. And that is actually your angle of correction. So looking at the ankle joint right now, changing your neck, looking here, rotating your head, gives you the rotation angle that actually defies what you have to do now. So this is line A. This is the axis of sight. Your head looks to the ankle joint. And now you rotate your head and look to your virtual point where the ankle joint has to be projected after the correction osteotomy. And that is line B. And in between those angles, between those lines, you form an angle A that you have to transpose to the medial cortex. And at that medial cortex, now there comes this translation process where you translate angles into metrics. And this is why these x-rays have to be calibrated in order to measure now the wedge base height. And then you're equipped with a value in terms of millimeters that gets you to the OR and equips you with something that you can do your surgery with. The only thing that you need there is actually a value, like, I don't know, 5 millimeters, 8 millimeters, whatsoever. So for the distal femur, we can run through this quickly, I guess. It's the same. It just goes upside down. So you look at it from, let's skip that. We'll talk about this later, is the techniques of distal femoral osteotomy and how to find your hinge point. Because I told you, you need an hinge point in order to do your planning there. So you actually need to draw your lines A and B to the hinge point. And the hinge point for the distal femoral osteotomy is always directly on top of the condyle of the contralateral side, so away from your starting cortex. Then you can draw a million lines to your starting cortex. But there is only one line, actually, that forms with a tangent onto the starting cortex, a 90 degree angle, being perpendicular to that. And if you found this specific one line, then you know where the center of your osteotomy is. And you can dial around everything. If you want to change 8 degrees, then it's 4 up, 4 down, summing up in 8 degrees, okay? So planning of such a closed wedge, we've been there. Now you have your hinge point, and then obviously you change the position again, and have the same animation for this. I guess for the sake of being a bit quicker, we just skip that. Would be interesting, but nonetheless, you, well, let's have 20 seconds that we invest there. So you just change your perspective. You become the hinge, and then you rotate around, and you see what happens there. These are your lines A, B, okay? So you just draw them, and then you have your two lines and your angle A transposition to the medial starting cortex, and that's it. So now Matt will tell you why doing this at either side may, in some surgeries, make good sense. That's not me. I just tell you now how we did it in the past. And that's obviously me in the past. And if you'd be able to listen to the music, it would be some kind of Charlie Chaplin motion picture 1940 stuff. Anyhow, so obviously we had to draw all those lines and measure those angles, and you can all do this manually. And you have to understand the principles behind it. And I think it's actually crucial to start off from scratch and get yourself some ruler and some pencil and just do the planning. And for a double level, you will find, oh, I cannot plan any further now because I cannot virtually play around with two osteotomies at a time in one planning. So you need to have some scissors and scotch tape, actually, to get the first planning done. And then you go for the second planning and so on. Obviously, these days are gone. And today is a little bit more sophisticated. So what we have today is planning tools, software. And there is software from many companies now providing us with tools that actually enable us to just morph the anatomy of the patient. And just by placing some dots, and the principles are actually everywhere the same, you get these MPTA and MLDFA angles. And so it indicates here at the table side here in the upper left-hand corner, it indicates in red figures and green figures what is out of range and what is within normal values. And so you know intuitively where the malalignment is. And what you do then is you throw in some coras, which by definition is just a hinge and a correction wedge. It's not really a cora because the center of rotation of angulation concept, which would be involved in this cora, is rather referred to shaft corrections. So when we talk about osteotomies about the knee, it's not so much cora. You just need hinges, OK? So you take some of those and put them inside. And for some of those corrections, you will see that the malalignment is not on one but on two levels. And if you'd be trying to correct these malalignments on one specific level, you'd be having to overdo this single level correction to an extent that you create a malalignment to the other side. So you have to overclean it to actually get it right when you look at Mikulich line only. But an isolated view at Mikulich line is what we call today a palliative surgery. So you do something for the sake of this Mikulich line to get the limb straight, but you completely forget about the joint line orientation. But there's Matt's part, OK? So this is why these tools give you the chance to actually place multiple corrections and sometimes even correct virtually within the joint, because even the joint line convergence angle, meaning the intra-articular wear, could be one source of malalignment. So there is potentially three malalignments, one in the femur, one in the tibia, and one at the level of the joint. So you see here what happens when you overdo it and bring the Mikulich line to your, well, let's say, adequate point at the intersection at the lateral spine. Then you have to open this by 17 millimeters. In fact, you have to open by 18, because it's an open wedge and you take out one millimeter saw blade thickness. You have to add that. So as a matter of fact, you create something which is a post-operative MPTA of maybe 100 degrees, and that is completely out of the range. So you go back to your drawing board in these situations and think, what can I do in order to get everything right? And so you offload this correction first at hand at the femoral side to have the option to go with a bit tinier correction at the tibia. And at the end, you just play around. And obviously, the software gives you all the options to virtually play around with all of this. And this is why software is great, but it's the second step in your learning phase. What is very important and really crucial is that you start off with manual planning on a radiograph, piece of paper. Get yourself some pencil and ruler and get things sorted there. OK, take-home mantra. Check for proper x-ray. Obviously, the x-ray needs to be properly aligned. If the x-ray is insufficient, as you've seen in the first case, you cannot plan on that. You need to have an analytic approach. And the analytic approach is always don't have an x-ray and plan on that. Have an x-ray and analyze it. Otherwise, you don't know what to plan. And here we come to the point, once again, the surgery is easy, but the indication behind it is not. So analysis of the malalignment is key. Focus on the hinge point. Whenever you ask yourself, well, where are these lines now? What do I have to do next? And when is my wife's birthday? And all these things that come into play are very difficult. And you just change your perspective, like always in life, and then you become a hinge, OK? Become hinges. Then you circulate the correction around that hinge and translate that to matrix. So whenever you want to see more about that, London, London, London, London, we invite you to come and share some of that stuff in the OR. And then I want to thank you for your audience. Thank you so much. OK, thanks very much, Christian. Great segue into our next talk, which is really going to talk to so Mathieu Olivier from France, who's another European star in the osteotomy world. He's going to talk to us about why joint line obliquity might be an issue and what we need to think about. Thank you. Thank you for the Europeans, the Americans, the other underworld people coming here. I'm very glad to see a full room of people want to learn about osteotomies. When we give those course with Christian in Europe, like 10 years ago, there was nobody in the room. Everybody was sleeping because there was free food and things like that at the end. But now we have overcrowded room all the time. So I think we can make osteotomy great again. This is the American joke. Anyway, so we're going to talk about. So if Christian thought was complex, this one is very complex. So I'm sorry about that. Take your time. Look at it. And if you have question at the end, it's a very tough concept here. Joint line obliquity, intra-articular correction. You will see that is the really second step of osteotomy understanding. So I will hope to give you everything in 10 minutes, but it's very tough. So I also have some disclosures relative to osteotomies. I would say something very easy to start. Indication of osteotomy. I'm not agree with Chris and Roberta Pratt. It's very, very easy. The indication of osteotomy is metaphyseal deformity. You don't have to think too much about the other stuff. Complex meniscus, complex cartilage. The ideal indication is just metaphyseal deformity. If you have a metaphyseal deformity at the tibia or the femur and you correct it, you have good outcomes. That's all. So if you have a patient, if you really want to have the good indication, develop osteotomy, femoral osteotomy, the main indication is just extra-articular deformity. And of course, the good indication of the UKA is the opposite. If you have a pure extra-articular deformity, the perfect indication is UKA. We don't have to discuss OTKA. There is a global deformity. But don't push yourself too much on that. If you have extra-articular deformity, go for extra-articular correction. If you have extra-articular deformity, go for extra-articular surgery. Don't think too much about that. So the reason one of jawline obliquity is it is a surgical mistake. So any patient with a too big jawline obliquity, let's say 5, 6 degrees after surgery, is mainly because you do something wrong during either your planning or your surgery. And I'm going to show you that. Reason one, you didn't realize that there was an intra-articular deformity that you tried to correct. And this is everything based on the other angle that Christian did not describe much, which is GLCA, the joint line convergence angle. This is the same patient in two stress view, varus and valgus. You see, the only thing that changes is not the tibial shape. Of course, you cannot deform bone by pressing varus and valgus. Eptex is to break them. But anyway, we don't go this far today, except maybe tomorrow in a cadaver lab. So the only thing that changes is the reducible part of the deformity, which is intra-articular. This is what people doing UKAs for years called the reducible varus, which is inside of the joint. This thing, you can correct it. You can really easily correct it by putting an implant on the medial side of the knee, or even doing an extra-articular correction, which start to get in complex. So this angle is key. Everything is there. You can indicate osteotomy just based on this angle. If you have a very big GLCA angle, it's correlate with ALBAC and Kelgren status. I mean that if you have a GLCA above six, you have arthritis, intra-articular deformity. And intra-articular deformity is not the perfect indication for osteotomy. If you have a very low GLCA and a big varus, that mean that most of the deformity is outside of the joint. So you correct the thing outside of the joint and the job is done. Everybody's happy. You, the patient, post-operative outcomes, everything is perfect. Not really, but it's a good start. So this angle can be defined as, let's say, a little sum. You can use what we call now the arithmetic HKA. You subtract MLDFA from MPTA. You have the extra-articular deformity. And you subtract GLCA from that. You have a value which is where the deformity is. If it's a negative value, everything is inside of the joint. If it's a very positive value, everything is outside of the joint. So you know that your indication can be solely based on these three angle measurements. This is a case of mine. This guy got MPTA 81, MLDFA 88, and no extra-articular deformity. But this guy is a perfect indication for HTO because you have almost a pure tibial deformity, which is a metaphyseal deformity. And his deformity location is seven, big varus outside of the joint. This is another case, not from mine. This guy got MPTA 86, femoral deformity, MLDFA 92, five degrees of extra-articular deformity in the varus, varus deformity in the femur, and a very big GLCA. So this guy has a minus one deformity location, meaning that most of the deformity is inside of the joint. We're gonna see this patient again in a few minutes. The second reason for having a joint line obliquity that is too big after the surgery is you do a wrong side correction. You didn't decide good. You didn't focus too much on intra-extra-articular deformity and specifically, you push too much. You push too much into your correction. This is my biomechanical teacher in my university, and we always discuss that about osteotomy. The problem is the conflict in between anatomical correction and biomechanical issues. So this guy is, this is the initial paper of Fujizawa. In the early 90s, these guys said, we need to switch the weight-bearing line from somewhere in varus to something in big valgus. And this is how the 54 patients will do better at the end. But remember, this is the operative x-rays. We don't do osteotomy on that anymore. We don't do major intra-articular deformity correction with osteotomies. So of course, these guys did a lot of push. You have a normal tibia at the beginning, a very shitty tibia valgus at the end. So these guys were the 70s, 80s clinical cases for osteotomy. Now a day, and then, Doug Dallin-Noyes came and said, this 65% to 70% correction is maybe too complex for us. Let's do empirically 72.5. It's admitted in their paper, they empirically decide that the good point was 62.5. So I think there is not much science behind this number. They just said, it's a good one, 62.5, let's do that. For 20 years, everybody admits that it was the ideal correction. Everybody, even us. Now we completely switch because we don't correct intra-articular arthritis anymore. So we switch to tiny correction. We switch to the 55%, which is in any ethnicity or individual, exactly the top of the spine, the lateral spine. This is funny. Mother nature gave us the perfect landmark. The lateral spine is 55% Fujizawa point, always in any ethnicity, gender, age. So of course, you can tailor that based on cartilage, menisci issues, and so on and so on. But this tiny correction would be good. If you focus on 55%, you don't have too much to think of, I need to do a 17 degree TBR correction. I need to do an 18 degree TBR correction. Because first, you don't focus to, you finally don't want to correct intra-articular deformity with HTOs. And second, you do tiny corrections, very small of a correction in valgus, one, two degree. So your correction is not as big as the correction of Fujizawa in the 70s. So you don't have to focus too much on that. So the second reason for having a big GLO is solely because you want to correct too much. Then, okay, I just need to do a 182 HKA or 55% Fujizawa line at the end, I will be out of trouble. Yeah, maybe, but look at that. 50% of osteotomy performed in France are done on the wrong bone. Same goes thing here. And the patient with virus deformity often have femoral deformity. So the virus deformity is not solely TBR problem, is potentially TBR, potentially femur, and often both. And if we publish that in Kesta, and so this problem of GLO is the same. This is my patient again. This guy had 15 degrees virus. Once again, no deformity in the tibia, some deformity in the femur, and a lot in the joint. What happened here is this. So the surgeon thinks that 20 degree correction would be a good idea with a hinge fracture at the beginning, of course, because he pushed so much in the tibia. And at the end, having an MPT of 103, of course, the femoral deformity didn't move because he didn't correct it. And the GLCA completely correct. This is what we call the intra-articular correction. And this happened. So this guy ends up with a 10-degree valgus at the end, because he corrects the good thing. He says, why not doing a 17-degree correction to finish with the 182-degree? But what happened then is the 7-degree GLCA disappeared because of the shift of the weight-bearing line. This is what we call the intra-articular correction. And one of the reasons for this very bad x-ray is everything correct. Now the jawline is perfect. It's 0-degree GLCA. But the obliquity is completely crap. So this patient would be unhappy for sure, because first, you have a 10-degree valgus leg. And second, you have a 10-degree obliquity. So we know for sure that this guy would do very bad in a very few moments. Because it's a problem of cars. You can have a straight car, but positive or negative cambers. So of course, you can say, OK, the ideal way is to correct the alignment of the car. The car needs to have two tires very straight. But once again, here, it's the same. They are pretty straight on the road. The two tires are touching. But once again, if you have an obliquity of the jawline, you will probably end up with a tire like that. The part of the tire is completely worn off after two or three years, because you're not rolling well. You're not putting the tire at a good position. Then, OK, so we said, it's maybe nothing in human beings. AGSN paper, more than 3-degree of GLO, bad clinical outcomes. More than six bad radiological outcomes. Those guys got lateral arthritis very fast. So you need to focus on normal value and threshold, not to push too much the obliquity of the jawline after the surgery. So wrong side correction, AGSN paper we published some months ago. You said a case study paper we published some months ago. We create a lot of problems. We create because we want to have normally a line leg at the end. We create obliquity. And the bad thing on that is that having those patients, first, they have bad clinical outcomes. And second, because we push too much on the tibia, we have complication, hinge fractures, non-unions. Instead of doing two tiny corrections that heal very fast, we do one big. And this one big is worse. This is what we have in this AGSN paper. We have more complication in big correction than two tiny corrections. So you can say, oh, this guy will say I need to do two plates, two cuts. I'm afraid of that. But in fact, you should be afraid about the big correction. Those ones will not heal. Those one we have hinge fractures. Those one will be an happy patient at the end. We publish a consensus on that with ESCA. I was chairman of that with Matt Dawson from UK. This is the guidelines. No obliquity over 5 degree and no MPTA over 94 after surgery. If you focus on that, you're out of problem. You will never have this bad obliquity things and so on and so on. So the new hope came by Christian Clay for me. This is Luke Clay Walker here. Because it told me how to do double level osteotomy. And it was a bright idea for me. This guy came to me and say, why are you doing this big tibia correction? It's meaningless. Just shoot at the femur. The deformity is femoral. And so this is what I do. This is a single stage bifocal bilateral surgery. So you can say I'm crazy. Maybe I am. But I really like to do this double level osteotomy surgery. For me, it's one of the best thing I can provide to patient. They're all very happy. Two tiny correction, full weight bearing day zero, no big problems. Because if you do a 17 degree opening, we all know that you will wait for ages to put those guys back on weight bearing. Evidence is, there is evidence on double level osteotomy. We published tons of paper on that, return to sport, complication rates, issues, unions, and so on and so on. This is my clinical activity in 2023. I've done already 121 various osteotomy this year. 35 of them were double level osteotomy. So if you really do a lot of osteotomy, you want to do double level osteotomy in at least one fourth of your cases. Because this is what it is. A fourth of your various patient get bifocal deformity. And the last reason is because we are chicken. We are afraid. You know, what is the matter? It's easy to do. For me, it's easier to do a femoral osteotomy than a tibial one. And all of the faculty here will teach you the tips and tricks to avoid problems and you will not have any problems. And finally, you get algorithm of correction. We can discuss hours on that. I think it's not the point. Christian showed you the planning. If you have a normal tibia and a various femur, do femoral osteotomy. If you have a normal femur and a various tibia, do a various osteotomy on the tibia. And if you have bifocal deformity, do double level osteotomy. And you're really safe out of trouble. Everything will be okay. So finally, is there any reason today to do all in the tibia correction? If you have people saying, go, no, don't listen to this shitty European guys. Do the 17 millimeter opening in the tibia. Yeah, it's easy. But tikia, easier. Let's just wait and do a tikia 10 years after. It will be even better for the patient. It's not surgically forgiving. You can might think that one surgical site is better, but it's not forgiving. You will break hinges. You have non-unions. You have issues. We have problem with void fillers. Everything will be bad with 20 degree opening in the tibia. And you can say there is no real proof that you should not have excess of joint line obliquity. The only proof if not a single of you got more than three degree of joint line obliquity. So why pushing? Why pushing? Lucy got two degrees of obliquity 3 million years ago. So why having more? It's meaningless. Just do the correction at the ankle then. It will be better maybe. And finally, early weight bearing if you don't do DFOs? Maybe, but after 15 degree correction and hinge fractures, patient can do no weight bearing for six months maybe. Thank you for attention, guys. Happy to work on that. So continuing with our round the world tour, we have David Parker from Sydney, Australia, who is also our current president of Issacus. Thank you, David. He's going to present is, what are you going to present? Patient specific instrumentation and navigation. Is it necessary? You're just so dazzled by the science. You can't think anymore, Eliza. Look, good morning, everyone. As previous speakers said, it's great to see a room full of people from around the world who are osteotomy enthusiasts or potential osteotomy enthusiasts. And Issacus is very excited to be involved in this course. And I want to thank Eliza and Al and Rob for putting it together. And also Laura from the Issacus office and Julie from the ASM office for putting this together and bringing it all together in a very sort of seamless fashion. These are my disclosures. The relevant one to osteotomy is personalized surgery. So the question that I think Al gave me for this talk is, is PSI and or navigation necessary to do an osteotomy? And I think you've already seen the question is, no. You don't have to do it. It's just another way of doing it. I think a lot of things that we do, a lot of the things that we're provided with, with arthroplasty, there are different tools. There are different things you can use. And you've got to work out what's going to help you. I think with careful preoperative planning and good surgical technique, you can get good results most of the time. Very similar to what we hear in the arthroplasty world. And I learned to do osteotomies in London, Ontario with Peter Fowler and Ned Amendola. And I measured them like this usually. And then we do osteotomy, simple free hand guide wire technique, opening wedge. We get our alignment right out and we take an x-ray. And if the x-ray was falling in the right spot, we'd say, good, we'd carry on. And I think the results were good. But when you're a fellow, you get three or four months follow up and you don't have any problems and all the results are perfect, right? And when you get into practice, then you start running out of complications that you haven't had. So that's what I did for sort of five or six years. And then about that 2006 time, I'd been using navigation for arthroplasty because I'm one of these strange non-US surgeons. I do all sorts of knee surgery. I do sports and arthroplasty. And so I thought, well, this, you know, navigation helps us with alignment and osteotomy is an alignment operation. So it makes sense to use it for osteotomy. So I think if you look at the case for using navigation, well, this is how we get good alignment. You've heard a lot about this already over the last 20 minutes or so. And we can make our preparative calculations. And how do we make a judgment during the procedure where we can get that alignment right out or we can just come around to the end of the bed and go, yeah, that looks about right. Or, and everything matches up with our preparative plan. But there are some limitations to that. We make these pictures from static long leg films and there's variability in that that we may not capture. And they don't incorporate specific features of patient's anatomy and dynamic alignment. And then that intraoperative fluoro, we all know we can make that rod fall where we want it to if you rotate the leg around a bit, push it this way, a bit of that. So it's a bit susceptible to different positioning. So there are limitations to that sort of freehand technique. And navigation, we thought could probably improve accuracy. And there's an assumption there that if you improve accuracy, you'll probably improve the outcomes. But there are, of course, disadvantages. Main one being that it's a pain in the neck, right? You need more equipment, it takes longer. And we know how it was difficult to get navigation to be taken up in the US for arthroplasty despite the fairly large evidence base behind it. So I've used it for many years for osteotomy, for HTO, for DFO. And this is the way we do it. It's basically exactly the same way I do an arthroplasty. So we register the center of the hip kinematically, we do the center of the knee arthroscopically, and we take the center of the ankle from the malleoli. And then we get our initial alignment. So that can be our initial alignment. We can stress it into varus, and we can stress into valgus to see what the correctability is. And we can compare that to our preoperative calculations. And if everything's lining up, then we know that that's probably gonna be a good guide when we do our correction because it matched our preoperative calculation. So it's just another sort of secondary check that we have. And then we do our osteotomy. And obviously, this favors more an opening wedge because you can open it and just watch your alignment change gradually until you get to the point that you wanna be. And then we assess it at the end, and we compare pre to post. And when we first started doing navigation, I think about our first 50 cases, we looked at their postoperative imaging. And we do the, for all of our cases, we do a six-month long-leg film and check their alignment. And we found that it correlated pretty well. So we're pretty happy that navigation was achieving what we wanted it to achieve in terms of patient's alignment. And therefore, that became our standard of care for many years. We've got a big database of osteotomies. I think we've got close to 600 patients. We've got about 432 of the medial opening wedge osteotomies. And I'm not gonna go through all their follow-up. But suffice to say, we think it's really important to do follow-up on the patients because we can do a very clever surgery, but it's not until you follow them up to know if it actually works. But I think the main critical point here is that we're normally aiming with our navigation for two and a half degrees of valgus. And you can see what we've achieved. So that's good, but what's really important is the standard deviation. And that comes across in the arthroplasty literature too, is not only is it more accurate, but it really reduces the outliers. So you can hit a bullseye without these tools, but you're much more likely to hit it more of the time if you use these types of tools. And that's probably the main message, it reduces the outlier. And there's a lot of literature around this, not as much as for arthroplasty, obviously, but the majority of them show improved accuracy and reduced outliers. So it's less likely that you'll have that dud case where you're way off the mark. So it's been my standard practice for about 15 years. We've published papers on this and we've been pretty happy with it. And then over the last few years, we've evolved more towards PSI. And I'll tell you why. So if we look at PSI and we look at osteotomy, I mean, you've heard already from a bunch of osteotomy enthusiasts, okay? And that doesn't necessarily translate to what happens in certain countries, particularly the US, it hasn't really been taken up very much, but it's a very successful operation, it's in the right person, it's a joint preserving operation. But despite that, arthroplasty is much more popular and many patients that we feel are suitable for osteotomy end up with a knee replacement, which we think is inappropriate. And we've got a registry in Australia, we can see how high the revision rate is in younger patients and often the satisfaction rate is not as high either. So I feel that osteotomy is underutilized. So why is this? Well, I think there are barriers to osteotomy. I think many of you will appreciate this, there's stresses around, well, how do you plan these? How do you choose the patients? How do you do the procedure safely? I've heard about these disasters, I don't wanna have those. It's much simpler if I can just cut along the dotted line and do a knee replacement. So I think if you can remove these barriers, the osteotomy becomes much more accessible to more people and it can be more appropriately utilized. So patients who are in their 30s or 40s who are getting this or getting this are more likely to get something like this. They've still got their own knee and they're probably, we've done a lot of studies looking at survival analysis and I think you can get survival beyond 20 years if you do it at the right time in the right patient. So PSI is an image-based modality, well-established in arthroplasty. When it first came out in arthroplasty, we looked at the accuracy of it and published a couple of papers and it wasn't very accurate then but I think the technology around it has improved a lot in the last 10 years. It allows us to do better planning and that's probably one of the main advantages in my opinion and it gets improved efficiency over navigation but hopefully with similar accuracy. And this has been done for HTOs for about 10 years or so with several different companies. So if we look at how we make our planning easier, so in Australia we use EOS, I think you have that available here but it's a low-dose, long-leg image in the AP and the lateral plane and it can give us all of those angles that Christian and Matthew have just been talking about and that can be done very easily on these imaging on these patients. And then you can analyze the deformity of each bone, you can determine where you wanna do your osteotomy in line with what Matthew was talking about, the principles there. You can then just put the alignment data into the app and the surgeon will then work out exactly where they want the alignment to be changed to in the coronal plane. So if you're gonna go with what Matthew said, you might be going to 55% or you may be choosing it in degrees and then you may wanna change the tibial slope as well and if you wanna change the tibial slope, then you can do that in the planning stage as well. So this just makes the planning of the whole thing a lot easier and then that gets translated to the patient's anatomy on their CT scan and then you do the virtual osteotomy, working at the angle and the wedge size and then they can create the plate and the PSI position. And then once we've got that, then the execution's a lot easier. So this is what we do. So this person here has got navigation pins on and a PSI. So for our first 50 or so cases, we had the navigation on board as well because I'm always paranoid that things are gonna be not quite perfect and so we had that just as a secondary backup check for the first few cases that we did and this is the imaging and this is the final case. And if we looked at the first 55 cases that we did, then we found it was very accurate, as I'll show you in a minute. So you go to the operating room with this information there. You know what your wedge size is gonna be, you know what your correction's gonna be, you know that when you put the PSI, this is what the fluoro should look like, you know how deep to cut, you know how deep to drill with your drills for the screws and you know what your wedge size is gonna be at the front and at the back so you don't change the slope any more than you want to. And so this is what we found when we did 55 cases, compared the navigation results to the PSI and you can see there that our correlation's in the 0.9. So very good and we're very happy to then just transition to using the PSI alone. So if I just illustrate that with a couple of cases and this goes to what Matthew was talking about, about joint line obliquity and we've done quite a lot of research around that as well from a finite element analysis showing that the obliquity of the joint line actually increased a lot on the lateral compartment beyond the actual change in alignment. So it can have effect on longer term survival as well, as well as a short term function. So this patient's got a weight bearing line that falls outside the joints, 45 years of age. I think in a lot of places he'd get a total knee replacement. He's had previous failed ligament surgery but he had a good lateral compartment and he was young, he was active. And just for planning purposes, you can see what happens when we plan the osteotomy all just on one level. We get exactly very similar case to what Matthew showed. He's got 10 degree obliquity in the joint line, he's got a 26 millimeter wedge, obviously not acceptable for all those reasons that have been articulated before. So we do a lateral closing wedge on the femur, a medial open wedge on the tibia, we retain a normal joint line and it's actually quite simple to do. And so this is the way we did it with the PSI guides and this is what he looks like eight weeks post-op. And these patients actually do really well in my experience and I'm sure Matthew's got a huge experience as is Christian. And then all our patients at six months get a gait analysis, so you can see the adductor moment hugely reduced here. And if we look at the ground reaction force, then you can see there preoperatively and postoperatively. So again, I think all that due diligence is really important to follow up your results to make sure everything you think was right turns out to be right. And just one more case, this is another case just to show how the planning can be made so easy. You see this patient here has a big recovitum deformity from a growth arrest as a young child. So if we take a scan of the other leg, we can see what the normal anatomy is and then we can plan our correction to try and get it back to the normal anatomy. We can make a PSI to do the screw holes for the plate, to do the tibial tubercle osteotomy, the next PSI to do the opening wedge osteotomy at the front, the next PSI to cut the allograft wedge that's gonna go in there, and then that's the end result. So it makes it somewhat complex operation, but very easy to do. So in conclusion, osteotomy can be done successfully without either PSI or navigation. Okay, you don't have to have it. I just think it makes things easier. I think navigation improves the accuracy and the reproducibility, but it adds time. And I don't think I'm gonna convert anybody in this room to using navigation. I'm pretty happy to accept that. But the PSI, I think it makes the planning easier. It makes the execution easier. It provides what we have found to be equivalent accuracy to navigation. And I think it removes a lot of the barriers that people find stressful about choosing and doing an osteotomy. And therefore, I hope it's gonna result in increased utilization of the procedure. So I'd like to thank you for your attention. Greetings from beautiful Sydney, Australia. And please mark your calendar for the ISCOS meeting in 2025 in Munich. Thanks. Thank you. Excellent. Thank you all to our speakers. And I'm sure many of you got lots and lots of questions regarding the previous talks. But really what we're gonna hope for is that during these next case discussions, a lot of these points are gonna be brought up and we can ask our specific speakers what their viewpoint is based on those cases that we're gonna discuss, okay? So it's a great pleasure now to introduce Maria Tuka from Santiago, Chile. And Maria's gonna provide us with a case of varus knee with medial OA. And so what we're gonna essentially do is Maria is gonna provide us with some information regarding the case. We're then gonna split up into groups. So just like I said, so the back two tables, the table in front, just turn around. So now you're essentially hoping to have groups of six. We'll make sure that there's a faculty member with each group. And we're gonna discuss it for five minutes and then come back, maybe Maria will then tell us what we did and we can throw it out there. So and Liza and I will sort of moderate the discussion as we go. This is an open discussion, lots of chat. And if you disagree with stuff, please let us know. And that's the whole point of this session. So Maria, over to you. Great, thanks. You wanna organize the tables now or when we stop for the questions? So you'll just do the first presentation. Great. Okay, so thanks for this invitation. I'm happy to be here. So now they are all experts in planning osteotomies. This is gonna be a piece of cake. So we'll just kind of chase. So those are my disclosures. So this is a classic case of a 42 year old man, construction supervisor, healthy, normal BMI, not a smoker, had an ACL reconstruction and a partial meniscectomy done 10 years ago, and has six months of progressive medial knee pain that has partial response to conservative treatment. And the highlights of the physical examination are that he has a symmetrical virus alignment, no effusion, stable and medial joint line tenderness, positive medial meniscus tests, and no lateral pain or patellofemoral joint pain. It's gonna be relevant for our decision making. So these are the x-rays. And I put here the contralateral healthy side so that we can compare and we see the narrowing of the joint line on the medial side, well, the screws of the ACL reconstruction, some subchondral sclerosis, and we're gonna see further details on the MRI. So here you can see the coronal cuts from posterior to anterior. And well, we can see some artifact from the screws that we have the evidence of the meniscal loss, significant medial meniscal loss. Also, besides some, the generative, like diffuse generative wear of the medial compartment, we see some focal chondral injuries, like of total width. And we see that we have a healthy or sort of healthy lateral compartment. We only have some, the generative tear of the anterior horn of the lateral meniscus, and some very small chondral lesion on the back of the condyle, and the patellofemoral joint looks quite healthy. This is the long sanding x-rays that we can see if we zoom here, how the axis goes to the medial compartment. This is a 16 millimeter deviation from the center of the knee. It has a 3.6 degrees of mechanical barriers. And the MPTA is 84, confirming the origin of this deformity seems to be in the tibia, as we have just learned. Joint line of liquidity is 1.4, and the TBBA angle confirms this is a metaphyseal varus. So, here you have the calculations of lateral slope and medial slope, that it's significantly increased. In this case, it's gonna be relevant. He has some prior ACL reconstruction, and a normal patellar height. So, all this being said, we're gonna go for the first round of questions. I put that x-ray so that you remember the degree of varus, but we can go back to any images if you need. So, what I'm going to ask you to discuss in your small groups is gonna be, is the patient a good candidate for a high tibial osteotomy? What is the amount of correction? We've gone through this, so what is gonna be your aim point for this case? In what cases you would go further lateral? Would you do an opening medial or a closing lateral, and what are the pros and cons of this? What about the tibial torosity in your biplanar osteotomy? When do you go in an L, or when do you choose an invert L? And how does the prior ACL reconstruction change your usual plan? Remember to talk and discuss about slope, about the position of your osteotomy. So, maybe afterwards, each of the table can answer one of these questions. So, you can now switch to the round things. Perfect. Thank you. Lysa, this one? Okay, everybody, are you ready to answer? Okay, people, we have to move on. So we'll start at Dr. Parker's table. So there's mics on each of the tables, but yeah, go for that one. So let's discuss on the first question. So what do you think about this patient as a good candidate? All right, guys. What would be your treatment of choice? We just had one question, Maria, and you probably covered this and I wasn't paying attention, but is the patient's knee stable? Yeah, it's stable and the graft is okay. So no anterior posterior instability or virus valgus instability at all. So our group was pretty happy that osteotomy was the right procedure for them. We noted those lateral compartment changes, but the anterior horn changes are usually insignificant, and it's a bit hard to see on the MRI scan, but I didn't think there was much. I think the main thing with post-ACL injury patients is making sure they haven't destroyed their posterior root, and it looked like it was okay. It was fine. Yeah. It was just a little degenerative tear in the anterior horn of the lateral meniscus and just like a minimal subchondral edema on the lateral femoral condyle. Other words, pretty healthy. So in summary, we felt that assuming they failed non-surgical as a good candidate, a couple of people talked about using an unloaded brace, and then I think there's regional differences in terms of the cost and availability, those sort of things. I mean, from my point of view, I think if you have a patient who gets the idea of an osteotomy, likes the idea of an osteotomy, I don't go through the process just for the sake of it, but it's more those people who are a bit questionable and not sure. Great. Thanks. Now, Volker's table. So what do you think about the amount of correction? Where do you aim it? Do you agree with Dr. Clay or with Fukuzawa? We were very happy that you showed a very clear-cut case with a big deformity, nothing else going on. What do you want to hear from me, you said? The amount of correction? Yeah. Where would you aim your osteotomy? Do you believe in Dr. Clay? My aim is going to be the needle with the hyaluronate is going to come from the antilateral portal. Is that my aim? Come on. If we're doing, well, then I send him to Sydney or to London or to London, London. The aim for, I mean, it would be a medial opening wedge, but you can't push me into surgery on this only because I'm here to answer this question. But the aim would be to shoot the hat of the head, right, and do all the nice correction. And if you overcorrect this guy to 62.5, he's going to hate you for the rest of his life. So you're getting maybe a three millimeter opening wedge. Now, our table said, can we maybe do an osteochondral graft, maybe do a meniscus graft. If that was his leg that you showed, big hairy leg, he doesn't look like an athlete that's hiking the mountains of Santiago. I don't know that that would be very good for him. So did I answer your question? Yep. Great. So I'm going to make a quick comment. Matthew already said we should only be correcting to 55%. Uh-huh. Okay. So he agrees. What did everybody discuss? So in our table, we are pretty doubtful about the indication of osteotomy. So I would say major closing or opening is the next question. I think everybody agree on major opening because I think everybody thinks it's easier. But the problem is, as Volker said, it would be a five millimeter correction, five degree correction. The real question is, would this change his life to do a very tiny correction to avoid the metaphyseal valgus at the end? Because this guy, I'm pretty sure he will have a UCA in 15 years. And probably it's his best option to replace a missing meniscus, a very bad cartilage situation If you overcorrect him, it's done. Yeah, you just neutralize the slope. You're buying time. You're buying time. Why did you say you would do what? I think you just said five millimeter correction. No, I think five millimeter correction is something, but will this five millimeter change his life? I don't know. So there is no big promise behind that. It's a very tiny correction for a major deficiency, meniscus deficiency. David? I think you just need to look at the natural history of this condition, right? I mean, and let's assume he's had all the right nonsurgery. David, we cannot hear, I think. Is the mic working? Can you hear me now? Yes. Okay. I think if you look at the natural history of this condition, it's very simple. You look at what your options are. And if we assume he's failed non-surgical treatment, you send him for his HA injections, you give him your unloaded brace, you come back, unloaded brace feels good, doc, but I still want something done. Okay? So just get past that, because that's what we're talking about. And that's just delaying things, okay? Yeah. And I think, you know, you can do it. So he needs something done now when he's age 42. And I don't think the size of the correction should make any real difference as to whether it's a worthwhile procedure. Yeah, we've done plenty of studies, and we've got long-term results out to 15 years. We've shown over two or three years you can see cartilage recovery. We get good clinical outcomes. We get good functional improvements. And the main thing that affects the survivor over the longer term is how bad their arthritis was when you did the osteotomy. Okay? None of the other factors that affects the long-term survival. So if you do an osteotomy on this guy, his symptoms will be a lot better, his cartilage progression will slow down, and you get a lot better results. Unis on 42-year-olds, when you're in a country that has a registry, we know they do badly. And a conversion of a uni to a total gets a much, much, much worse result than a conversion of an HTO with a small correction that doesn't distort the anatomy to a total knee. So yes, we have to make sure we give him all the non-surgical treatment first, but I would strongly argue that he'll get a good outcome with an osteotomy, and he will be happy. Yeah, as long as he has reasonable expectations. Yeah, we've done studies where we've looked at their KUS scores pre and post. They get a big improvement, but if you compare their KUS scores to age-matched norms, they're not as good. And I show the patients that graph. I say, we can make you better. We can't make you normal. Al, can I make a comment? Anya. Why is that? And I asked somebody over there, and they said, well, we've got a problem. I have a very big arthroplasty lobby around me that I need to fight on this. So anyway, the patient, if they buy in, if they understand the improvement may not be going to 100%, but I don't know, do you all use IKDC PROs to kind of judge a little bit where they come in? They come in at 20 or they come in at 50, do you, PROs? Two people? That's it. Three people. Oh, cool. But any type of TO. Just talk. Okay. All right. Okay, can I make a comment? So a couple things. I think an arthroplasty on this patient is malpractice. He's a construction worker and he's got a meal compartment and he's young. And my last name is Ranawat. So that's horrible. I also would say for the 75% of the U.S. surgeons with a small deformity, chondral loss in his meal compartment, it's not a problem. It's not a problem. 95% of surgeons in America would do an isolated cartilage procedure, which is wrong. That's one thing on our thing that, you know, I'd want to talk about, because it's not indications for osteotomy. It's back to Dr. LaPrade's point is picking the right patient is contraindicated for isolated cartilage procedure. And I don't care which cartilage procedure you want to talk about, whether it's an osteolograph, a microfracture, anything. It's not going to work in this patient. That's the biggest teaching point to this case. And if you do do an osteotomy, I don't care what fake cartilage you put in the knee, or if you don't do any fake cartilage in the knee. I still do fake cartilage because I'm an American. But it doesn't matter, because the osteotomy is the most important part. Now, will it be a home run osteotomy? No. This is starting a degradative knee process. His knee is still going to age. I'm going to say, I'm going to get you to work for 20 more years, and then I'm going to get your arthroplasty. Thanks, Dr. Runaway. So we'll have to move on, because we have time for this case. OK, so let's go quickly. I'm going to just answer the question and show the resolution. So we thought it was a good candidate. The amount of correction, we aim it to the apex of the lateral spine, as this has been already shown, that this is how it shifts the weight-bearing opening, close. We're going to skip all this. So the answer to the L-inverter or not, that is my threshold. I only go down when it's corrections of more than 10 degrees, and Katonda Shamp's less than 1, that it's a weird case. And the ACL reconstruction changed our plan, since that would be probably the position of her usual osteotomy, and that had to be in this case. We could have removed the screw, but we prefer to avoid it. And the most important thing here is to not change the slope, and we know that this depends more on the position of the hinge than on the position of the plate, but to consider both. So this is how we calculate, always Minacci and Dugdale, just to double check. That's how we plan our osteotomy, the safe areas, how you calculate. We in our hospital, this is a plate that we have as a solicitation. So we don't have, in spite that we make a very precise calculation, we have the degrees that are set by the plate. So this was the final result, and we achieved what we expected, there was a valvus within two and three degrees. Thank you. So now being 20 years down the road, how does the patient feel? Christian, I don't have patients, I had 20 years of pull-up, luckily. Running the Chicago Marathon this weekend. While that's coming up, can I just make one more comment? I just think it's a really important point here about how you choose the patients, because the way this person ends up with a knee replacement is because people think of all the downside of doing an osteotomy, you know, like it's been talked about here. They may not be perfectly happy, you know, we're not dealing with a cartilage, et cetera, et cetera. They may end up with a total knee replacement, which is the worst possible thing you can do, okay? So you have to sort of think, it's like when you're deciding anything, you have to think, okay, what's the worst possible outcome of doing this, what's the best possible? And it allows you to have a very simple decision-making algorithm. And if you do a good osteotomy, they'll get a good improvement, you've burned zero bridges, and you'll make them happy. If you do a total knee replacement, then as Anil said, I personally agree with him, that we get a lot of surgeons coming to us in Australia, we'll put up a case like that, and if they're from the U.S., they almost 100% say total knee. So I think that I'm hoping that everybody is here because the paradigm is shifting and people are thinking more about doing something joint preserving. Nonetheless, I guess that was a difficult case and plenty of options, and I like the idea of first making up your mind on exclusion criteria. No full thickness defect, there's no arthroplasty, deviation of the joint line, there's no isolated cartilage procedure. Obviously, we know that he has a deviation, so if we want to do something, then osteotomy will help us to bring down progression rates and acceleration of degeneration. So all these things come into play, and we have to decide along with the patient, I guess. Cannot do this on x-rays here. There's a question. You need to use the mic. Keep pressing as you talk. The green mic goes on. Keep pressing as you talk. Okay, so speaking of exclusion criteria, I think that's a good question. You need to use the mic. Keep pressing as you talk. The green mic goes on. Keep pressing as you talk. Okay, so speaking of exclusion criteria, I practice in Wisconsin where I'm small, and what role does BMI play in this patient, like for instance, is there a BMI criteria that you would have for proceeding with this procedure? I don't think any of the Europeans can answer. So BMI in terms of what procedure? You're talking about an osteotomy now, okay. So I mean, you could make up your mind and say, if I'm concerned with the stability of the construct, you could still say I do a lateral closing wedge. Would come to the same biomechanics and gives you more primary stability. We personally are not really concerned with that, and we have found in our own database and throughout the statistics that actually high BMIs are no exclusion criteria, and we've published that in the ASCA consensus. And you could equally say you add an adjunct there and put some donor bone inside. We do this in England in 100% of the cases. In Germany, where I practice mostly, I don't have access to a bone bank. So it's actually by law forbidden there. So we have to deal with that as well. But it does not really compromise the stability. It's rather like a cork in the bottle and helps you to stop the bleeding and therefore gives you, reduces other side effects. But nonetheless, there is no BMI contraindication. Ned, I was going to ask you as a prominent osteotomy surgeon in the United States, do you have a BMI cut off for an opening wedge medial high tibial osteotomy? I mean, it's a bit provoking, obviously, but what do you do with a BMI-45 that comes to you with a fracture? Okay, okay, okay. We're... Huh? So sorry. So sorry. We have plenty of time. Okay. The next case is going to be presented by Rodrigo Laestro from Buenos Aires. We're going to kind of switch compartments now. A valgus knee with lateral OA. Take it away. Okay. Thank you for the kind invitation for this incredible course. One of the cases is about a valgus knee with lateral osteoarthritis. My name is Rodrigo Laestro. This is my disclosure. The case is a woman of 45 years. They have only lateral pain, no medial pain, no patellofemoral pain. This is an unstable knee. Some sign of it is locking, numbness. I think the more important thing in this case is to discuss with the patient, to see the patient in the office, to see, walk in the patient, discuss the expectation of the surgery. Here only we put some x-rays, some exam, and the more important thing is to discuss with the patient. Concerning the exams, we think that x-rays is the more important thing. MRI, of course, and CT, if you have some doubt of rotation of the knee of the femur. This is the case. This is the x-rays. You can see the right knee, the lateral compartment. In lateral views and merchant view about the patella, this is okay. No problem with femoral anteversion or extra rotation. This is the x-ray to see the ACL and PCL are okay. The lateral compartment, the medial compartment, the patellofemoral compartment is okay. The more important thing is this, the hip, knee, ankle weight-bearing x-ray. This is the normal values, and you can see there the patient. The problem is in the femur and a little in the tibia. I know that the European guys might do say that here, a double osteotomy, but this in the tibia is only 91. You know the anatomical femoral angle is not useful for this patient. The more important angle is this. We talked about this this morning, and this is the patient. I have a distal lateral femoral angle of 83. I think I will stop here because then it's to the planning of the osteotomy. I think we stop here and discuss the plan. Again, the questions we'll ask are what would you do and... Opening, closing, you know. Would you do an osteotomy, where and what kind, technique? Okay, let's discuss. Okay, in the same groups. Valgus deformity, okay, perfect, and lateral joint pain. So what are our options then? Okay, so I would say it looked like a full thickness defect almost, and the meniscus wasn't really there anymore. I would say in general, there is obviously plenty of options. So one option is nothing. Conservative treatment. Option number two is surgery. So out of surgery, now what can we do? We can realign her, and that would probably be an osteotomy. OK, let's keep it like that. And what would be another option for her? Well, yeah, right. OK, so we could talk about joint replacements. What would be the preferred joint replacement for you here? Total knee. Why not a uni? OK, so it's only, let's say, medial side is fine. Lateral side is destructive. We could do either of that. So let's say these, let's just say. And then now, I mean, we're at an osteotomy course. Let's focus on the osteotomy here. What should we do there? What would you do? What would be the preferred idea for this patient? Good point, good point. So you can see how she responds. So let's say she's a well responder. Okay, so you could go for an osteotomy. What would be your first step if you want to do an osteotomy? What's your what's your what's your first step for your osteotomy? Okay, perfect. So Very important So she got it already so first thing when we when we go here then the first thing we do Okay Analysis of the malalignment. Okay, so look into the figures. What does the analysis show us? And he was a bit sneaky because he actually pointed us towards one direction, but but read up the figure So I give you the MLDFA is 83 point two nine and the MPTA is ninety one point seven one So it's bifocal and what side is worse? What level is worse? By how many how many degrees? 0.4 Yeah so if you say there is a malalignment at the at the femur of 1.8 degrees and and at the tibia of I don't know Two degrees so not even huh, so 1.7 then actually you don't have you don't have have have The malalignments opting for one particular side very strongly Yeah, and let's be honest. These these are just measured so you can probably measure them the other way around so the malalignment is Pretty much the same at each level Okay, so that's a great rule of thumb, good, good, good, good gizmo here actually. Look at Miculich line, whenever the Miculich line does not touch the knee anymore, the baseline of the knee, then most likely there's a double level osteotomy, not in every case, but think about that. So that's a rule of thumb and it helps you a lot. So let's pretend that in this case that's not the case, so Miculich line does gonna touch the knee. So where to correct now? Is it a TFO and is it a lateral opening or a medial closing? Is it an HTO? Is it lateral opening? What is it? All right, we're gonna move forward. Okay, I love distal femoral osteotomies, in this particular case, having two degrees of either side, I would probably do a medial closing where to correct the osteotomy, because Since David Parker just threw you the phone, why don't we start with table one, yeah. Yeah, you know, we talked about 45-year-old sedentary female. All right, guys, Christian, everyone, quiet down, thank you. We entertained Volker's idea of non-operative management, maximizing that, giving consideration to is this patient ideal osteotomy candidate. We can maybe stop these disclaimers a little bit, but a little bit, yeah, I'm validating with your expertise. But given that, if we assume that we're going down the road osteotomy, we talked about whether it makes sense to do it on the tibia, based on this alignment and the measurements, the tibia wasn't the best source, we thought the femur would be better, and we debated a little bit of doing a lateral opening versus a medial closing. I think a lot of the surgeons that don't do a lot of osteotomies are a lot more familiar with the lateral approach. We talked a little bit about the patellofemoral mechanics, too, and Q angle, and so we landed towards a lateral opening wedge osteotomy. Dr. Parker wanted a medial closing wedge. Could you address if you're doing an osteotomy on the femur, it only affects extension and ad flexion? Yeah, we didn't specifically discuss that, but that's always a concern if you're doing a femoral-based osteotomy, you're only addressing it in full extension and not as the knee goes into flexion. If that's not intuitive, just think about it in the lab and bend the knee and take it through a range of motion, but yeah, that's the classic concern about doing a femoral-based osteotomy. I think here, given that the deformity is primarily femoral, we still landed on the femoral side of the correction. Do you think femoral study has no effect in flexion? Is that what I said? No, I do think that it's- I just want to know your advice for deciding that. I know that that's directed for ophthalmologists. Oh, please. What's your advice for deciding that? You're calling me an arthroplasty person? No, my reason for saying is I think that you have, for a lateral-sided OA, your deformity, your joint space narrowing is much more relevant in the PA view, so as much as all the PA view came to look at medial compartment, the lateral compartment tells you more information. And I think that for people, and maybe I am thinking of the severely arthritic, their problem is inflection. They have problems going down steps, they feel like they step in a pothole, and if you look at the deformity in the posterior condyle of the tibial plateau, it is actually a little cupola effect. So I'm not sure, I mean, I think theoretically, I think that it helps, but I wish that there was some way that I could change inflection as well. David, I would say there was a paper that was just presented at AOSSM from Armando, and Armando clearly showed everything that you just said in a very elegant six-degree freedom robot model that clearly just doing a femoral work offloads an extension and slowly degrades inflection. So it was a very nice paper, and that was we had a whole session debating tibia versus femoral-sided. But in this case, you can make the argument. I would say that would be the argument for her left knee, because in the left knee, her lateral compartment looks beautiful, and I guarantee your flexion weight bearing and lateral compartment is narrowed. Her right knee, you could say, look, in extension, she's showing extension disease. So from that point of view, I can make an argument you could do femoral work here. This goes back to Matt's rule, right? Not all valgus is in the femur, not all varus is in the tibia. Anybody else want to make any points that we haven't touched upon? Yes, Seth. Yeah, our group talked about whenever the weight-bearing line is outside of the bones that we start at least thinking about bifocal double levels and have to have good reasons not to do it. Christian talked about medial closing wedge on the tibia. That might be his preference in isolation. I would worry that it would need to be a big correction. Well, in this case, obviously, it looks as if, as the micro-lidge line doesn't touch the bone anymore, probably my go-to solution for the right side would be a double-level osteotomy, but we have to plan this. So as a general rule of thumb, like if you just eyeball a case and you see that the weight-bearing axis is not even in the joint, then you then start automatically... Right, that's 95%, I would say. And on the other side, I 100% agree. If you look at the tibia, at the long leg, just on the left-hand side, and you look at the axis, the micro-lidge axis, which is drawn across it, and then at the proximal joint line of the tibia, it indicates that the left side tibia has an MPTA of 91, 92. So probably that's the next side she comes with. But it doesn't look like a bilateral on that side. So you could be probably doing a medial-closing wedge high-tibia osteotomy on the left side if she complains there. That would have been an instructive case for such a scenario. And the right side, because of not touching micro-lidge, missing the knee actually is a double-level probably. But once again, it's putting all this into software and plan it. Yeah. Go. Okay. We planned 12 degrees of correction. Now we use this app that's similar that showed the European guys. Of course, if you have the navigation, it's more accurate. And this is the difference of open-closing it. And this is the scope of this patient. You see the medial compartment, the patellar femoral compartment is very good. ACL okay, but look, the lateral compartment is so bad. And this is the surgical technique, the lateral opening. We perform a B-planar osteotomy, as you can see in the right X-ray. This is another patient. You can put on work to protect the medial cortex. And this is the B-planar osteotomy. We put a three-cortical bone graft, one and two, 12 millimeters of distance. And this is the log plate final. This is some paper of Alan that they say they bring patient to go to zero degree in the femur. And remember that we only have 21 patients in his paper. Thank you. So he'll present a varicose knee with lateral laxity. And just while he's hooking up his computer, we do have a fourth case that's in a pediatric case. This will be part of your website because we're running out of time and Henry feels that the pediatric world is pretty easy. I'm not gonna agree with that. So Henry, can you just stand up? So, because really I want, because if any of you have a specific questions about pediatrics, please see him. It will be on the website. So you can go through his case, which is quite elegant. So thanks, Henry. Just while Rob gets set up there. So we're gonna do that last case, the PFO. How many are doing a lateral opening lift? Raise your hands. Just there. Okay, and a medial closing lift. By tomorrow, everybody will be doing medial closing lifts. Okay. Okay. So this is a Jorge presentation and I don't do keynotes. So it'll be interesting to see how this goes, but Jorge's level of understanding of things is a lot higher than mine. So I'm gonna go through a patient that has a posterolateral corner injury and has a varus knee, and this is a chronic posterolateral corner injury. So the case is a 33-year-old professional surfer with a right knee injury. He was seen in the Palo Alto area in California and diagnosed with a FCL tear, was told it would heal, was braced, and over the course of a year, he did not have it heal and still had problems. So he couldn't push off to his right side, had problems with hyperextension, and his brace was stabilizing him, but he couldn't be a professional surfer with the brace on. So physical exam, had the hyperextension, had four centimeters extra heel height on that side. Remember, this is a posterolateral corner injury too. That's why we're looking at this. Varus was two plus in extension and three plus at 30 degrees in knee flexion. So alignment-wise, his alignment x-ray, you can see that he's in mild to moderate amount of Varus. Playing radiographs normally, has no joint space narrowing. Stress radiographs showed a 2.5 millimeter side-to-side difference. In the literature, it's anywhere from two to 2.7, can be consistent with a complete tear of the FCL, but he's had a chronic injury, can't push off on that side, and bracing makes him better. So imaging-wise, FCL is scarring. We know from the literature that chronic FCL tears, you can't diagnose them, an MRI has to be a physical exam, and stress radiographs, there's a partial tear of his biceps off the fibular head, which in my world, that usually means that's the cause of the hyperextension when there's a FCL with a biceps tear, and the rest of his knee is essentially normal. The articular cartilage is menisci, ACL, PCL, and medial side are normal. So what would you do in this situation? So if we go through and discuss the alignment issue with a posterolateral, and would you stage this, so look at one reconstruction, his popliteus tendon is normal. Okay, so it's mainly FCL, isolated FCL, varus knee. Yeah, so a good question. With gait, he does have some varus thrust with gait. You could with a hyperextension, yes. But it's 2.5 millimeters on the varus, so it's not like a bad posterolateral coronary with five or six millimeters of gap. Thank you. What are the clinical findings for this chap? Hm? Instability. Okay, he's instable. Where is he instable? Here, postralateral corner, PLC. Yeah. Yeah. Postralateral corner, I would say so. chap with his Micolich line with a PLC repair alone in a chronic state, would you say that? Yeah, yeah, well the question first at hand is, is a posterolateral corner reconstruction helpful in this chap? Yeah, he hasn't, he has a hyper, well I wouldn't do it anyhow, he has a, I know what I would do in this case. Yeah, we did. As I said, I do probably more hip replacements today than HTOs, but I was working obviously for ages, and I don't know, I've done 3,000 HTOs in my life. So, this is obviously a chronic, mild situation where we would have done a normal HTO. The only thing that makes me think about the combined procedure in this chap, that he's a professional sportsman, he's a surfer. So, is that enough for a surfer, actually? It would be enough for the random guy to actually do a HTO in this case. He would be having... So my take on in this case would be, I would be trying to do an HTO. I would be trying to do an HTO and get away with that. Because here, this is a typical case where actually an osteotomy helps you by morphological change to fix a ligament issue. It's like in chronic ACL or chronic PCL problems where you do a flexion osteotomy just to, if you say, well, do a third revision, PCL replacement, and you cannot fix that, then you look at the slopes of the flexion osteotomy and that will probably do the job. Because the bone is obviously way stronger than the ligament. Okay, let's go around the room and see what people would do. Al? Your group over there. Yeah, so. You know, the thing that we're really interested in is understanding the deformity. So varus looks like they're on the contralateral side as well. Not a massive tibial. Looking at doing, opening wedge. Talked a lot about whether or not we do the post-lateral. The same. Who's your work group? The post-lateral. Oh, but that's 60% professional athlete. At the same time as doing a medial opening wedge. Volker? Yeah, I mean, you presented the case so elegantly. I think the key that all the young people in the room need to understand is you need to recognize this. You need to watch them when they're, if you have 80 patients that day and you don't watch them walk into the room and you don't see the thrust, then you already have a problem because all you see is the varus, you go after it, but they continue to have the LCL deficiency. The only thing we were missing is the slope, so assuming that's normal. We were missing the PCL, assuming that's normal. We would do a one-stage medial opening wedge, fibula-based allograft. Allograft? Allograft? Semitendinosus autograft? Why? Okay, good. No, I'm just kidding. The MRI was, it looked like, now I'm thinking that the FCL was in practice. It's a chronic MRI. So the stress radiograph shows 2.5 millimeters. Correct, it's in continuity and stretched. Well, they used to do that in the 1970s, so maybe. Al, would you put a synthetic to it if you do your advancement? Anybody else? Tables wise? Yes. We talked about a couple of things. One is the underlying, you know, physiologic varus. You know, one of the members here brought up the point that he does have a little bit of varus in his normal knee. And we just discussed that you really can't pay attention to the normal knee. You've got to pay attention to the abnormal knee because once you get a ligamentous injury, you can't really control your knee. So you have to look at the whole alignment. And we talked about just doing an osteotomy to correct this. I think this is not a significant deformity. It's not a significant instability. But we felt that doing a small osteotomy where you corrected the varus and maybe increased the slope one or two degrees would help with the hyperextension instability as well and just do that as a first stage surgery. Rob? I think it's important to understand what someone does when they surf. And we get a lot of surfers in Australia. And it's important to understand whether it's their front leg or their back leg. So if it's their back leg, which usually the right leg is, then when they're down, they're putting a lot of valgus load. And when they get up, that's when they'll get that extension. And it's probably the hyperextension that bothers him more when he's getting up. And I totally agree with Ned that you have to do something to the slope. You can't expect your reconstruction to affect the hyperextension. We talked about how much you correct them. And I think it depends on whether you're going to do a reconstruction because if you're doing a reconstruction, you just want to take off the abnormal force on the reconstruction, so you correct them to neutral. If you're not going to do a reconstruction, then you're expecting your alignment change to compensate for the instability, so you might want to take a bit beyond the midline. So a lot of things to think about. The other thing, it doesn't sound like it's the case here, but those surfers, if it's their back leg, they often get a lot of post-lateral chondral wear. I've seen plenty of professional surfers who have that because they're just loading it all the time in valgus. Good points. So I'll show you what we did here. that can figure out Jorge's system here. So arthroscopic pictures, obviously he's got a lateral compartment drive-through sign. As David said, you have to look for wear in the back, but he did not have articular cartilage wear. So what we plan to do is do the biceps repair and the anatomic FCL reconstruction. We used his own hamstring. People could argue it's probably not a big difference. We did the proximal tibial osteotomy with that concurrently. So here's his alignment change. The stress x-rays is 0.4 millimeters. His quad limb asymmetry index was 94%, and his heel height was symmetric between both sides. And here is back. You can see his back leg putting all the stress on it. So give me three or four minutes more of discussion while I'm running to the lab now because I'm doing the next demo. our group talked about, we had 100% agreement that if this was acute or subacute posterolateral coronary with that alignment that we would not be doing osteotomy. Is there anyone in here that feels different about that? And then we. So you're saying who would not do an osteotomy? Yeah, so if it was acute or subacute posterolateral coronary in this professional surfer, we're doing a posterolateral coronary reconstruction, is anyone doing an HTO in that patient? Not without alignment. Okay, so that was our thoughts as well. And then for the second point, in the chronic setting, we were in 100% agreement for fixing the alignment. And really the thing that tipped us over to doing the stabilization as well was the pro-athlete part. We didn't have the luxury of doing the osteotomy, waiting and seeing and guessing wrong on his time frames and having to go back for a stage posterolateral corner. And the morbidity of a fibular base was fairly low. If this was a Leprod style with a tibial, you know, where you needed a bigger posterolateral corner, then I think it's less practical and more morbid to do them both together. What can you do? So if you've got a big, significant rotatory laxity and you wanna do posterolateral coronary plus HTO, you can do a lateral closing wedge, right? You can still do a lateral closing wedge and you can still do your tibial tunnel. So there's lots of different options. And you know, tomorrow in the lab, you wanna be fast at doing both medial opening wedge, lateral closing wedge, have all of the tools available to you. Volker, question to you, if that patient that Rob showed had their contralateral leg is neutral alignment, so there's really no proximal tibial deformity, and that patient presents with varus with a posterolateral corner and it's chronic, how are you tackling that? Kind of. David? Like, I mean, are we... Should we be doing an osteotomy in that scenario when the majority of the deformity is created by the soft tissue laxity? That's what I'm getting at. Yes. The alignment would not allow us to just go for a soft tissue procedure, especially in a pro athlete. And my only question in such a case is if a simple HTO alone would have solved the problem anyhow. But this is debatable and remains unproven because it has been done and carried out in a different way. We have a case series of posterolateral corner injuries that we treated isolatedly with a normal medial open wedge HTO. And it gives great results. And for the normal guys, you don't have to add any constraint at the lateral side and have to fix the PLC. But for a pro athlete, it may not have been good enough. But who knows. Can't answer this. All right. We're going to move on to the demonstrations. David Parker will oversee it. I just want to say, as you guys have noticed, we didn't have any breaks, so obviously feel free to take breaks. We do have a break in the late afternoon. Please make sure you visit our vendors, and also please come early tomorrow. The vendors will be here. And so we'll be moving on with the medial meniscus post-reboot repair. All right. Okay. So Rob, can you hear me? I can hear you. Can you hear me okay, David? Yeah. Perfectly. Thanks, Rob. So, guys, in the audience, if you have questions, just tell me, and I'll feed them through to Rob. But otherwise, I'll let Rob get started. Thanks, Rob. Thank you. So I think this is a common question that we get is, how do we do a root repair for medial root, some invarious alignment, maybe a little bit of arthritis? And most of the literature says that root repairs at a higher risk of failure are not doing as well with PROMs if somebody's invarious. So it's a common thing to look at. So when we're looking at doing our repairs, I think it's important that you have good planning to go in, because you can't really do the osteotomy first. You have to do the root repair first, because your construct has a risk of getting in the way of drilling the tunnels, and also of having a fracture if you do that. So what we'll do first, as part of our procedure, is do the approach for the osteotomy first. So we'll make the anteromedial incision, and then dissect down and do the MCL release that we need to be able to do to get to the back of the knee. And with that, you don't have to do the trephonation approximately of your MCL to gain access, because you'll have the valgus gapping that you need to gain good access. So the second point is, you get your retractors in and see where you want to place your osteotomy. So we're using this specimen with Dr. Amendolonex. I put in the methylene blue, where I thought he'd be putting it. He's put the two pins in to show where he wants to do the osteotomy. And obviously, you have to look at your trajectory of drilling your tunnels, whether it's one tunnel or two tunnels, for the root repair that has to be above the osteotomy. So planning that out, doing the approach first, seeing where you want to place your osteotomy, trying to think about it in a postgraduate way, in terms of making sure that you're high enough with your root repair, and having the osteotomy at the desired location, so it's under the patellar tendon, and you can make sure you retract posteriorly, are two important steps to start out with this. And I think if you do this, it makes it a lot easier to go intra-articulately and address the pathology. Any questions? Yeah, Rob, are you planning, or is Ned planning, a uniplanar or a biplanar osteotomy? Uniplanar. Uniplanar. Okay. Is there an argument here, with a biplanar, if you wanted to make your proximal fragment a bit bigger to bring it down, to give you a bit more room for your root repair? To bring your osteotomy distally? I think that's a good point, David. I think it would bring it a little bit more distal. I think in this particular situation, we're going to be distal to these two guide wires we put in, so I think Rob's got it all planned out. Yeah. Okay. Good. Thanks. So, we'll go in and do our approach. Obviously, this is not an optimal candidate for doing a root repair, but we've created a root tear in the back of the knee. We want to make sure we're appropriately mobilized to be able to pull the meniscus back into place, so that's an important part of the root tears, is if they're retracted chronically and sublux posteriorly, doing a non-anatomic repair is going to result in the meniscus still being significantly extruded and not having normal weight-bearing capacity. So we want to make sure that we can mobilize the meniscus to the attachment site. Remember the attachment site is not up on the plateau. It's close to the PCL, so we've cleaned out this area, the PCL here, and decorticated this. Any type of curved curette can be effective at doing this. I've already done that ahead of time, but just going in and cleaning off this area to make sure that you have a good bleeding bed for the bone to optimize your root repair and give it the best chance for healing is your goal. So the technique that we use most commonly is to do two tunnels. The reason we do two tunnels is we've done a lot of second-look arthroscopies when bone grafting for ACLs, and when we have two tunnels that are spread apart, it gives a more broad-based repair of the root, and it seems like those heal down better than just having one tunnel, or it seems like the meniscus is still floating around the edges more diffusely. So we use two tunnels. Here's one of the guides that's utilized. You can see it's angulated to the right and to the left. This one's to the left, so we can place it around the tibial eminence. And then probably the technical issue to understand with this is that you have to change your angle so that when you push the guide down, you're going to be above where your desired location of your osteotomy is. So if it's not above that, you've already made it so it's going to be difficult to place it without damaging your meniscal suture configurations. So we've already placed those two in just for time reasons. After we get the first one in, we'd use this offset guide here. It's set to between five and seven millimeters, so you can see where you want to place it. When you get used to doing a lot of root repairs, you can make it two or three millimeters apart just by dropping your hand or elevating your hand, depending upon where you are. So optimally, for a root repair with an osteotomy, you're trying to put the first pin in posteriorly and we're going to stick the pin up the cannula just to show when we reamed it in there where it's going. So we want it to be far enough posterior that the next one can be anterior. Because if you made it too anterior, then as part of your planning, you have to worry about crossing the osteotomy site. So if we make it posterior, then I can use my offset guide and place it more anterior and make sure that we're having the cannulas come out within the area that we've prepared for the decortication. So the next step is to place in your suture anchors. So we're going to place in the meniscus that's already extruded on us. I want to get a really good bite of the tissue and make sure that we're getting a good repair. So pulling it over, making sure I'm getting close to it, making sure I have a good bite. It's a self-capture device. Try to twist it to see if you're out. I hope I am. Then I like to put in a vertical mattress in the majority of these. So we'll reposition the tape. On the guide, your portal has to be big so you don't get fat pad impingement and catching it. And then give me a little bit more valgus. And Rob, are you trying to get as much of the meniscus as you can in that bite? Yeah, I'm trying to get a really big bite for the first one. The second one, you can kind of adapt it, but you can see our meniscus is already extruded posteriorly. The 15 minutes it took just to prep the knee. And for the audience, if the meniscus is a bit stuck, what are your tips for mobilizing it? So I'll use a scissor biter to release it. I know you have to worry about the meniscal tibial attachment site, but it gets so scarred in there that you have to do a release. Just hold that for a second. I just want to grab it. I'm going to try to make sure I pull it back in a little bit better. So you can see that I've actually done a little bit of a meniscal tibial release, David, just so I can ensure that this doesn't get caught in there. The only technical issue is when you do have these curved self-capture devices, they're a little bit harder to get the second one in, as opposed to a straight one, but I prefer to use this one so I get the first bite exactly where I want it. I don't think I got a good bite there. It's a little bit hard when I can't shift my weight to kind of get myself back in there. I'm going to come out one more time. Here, just hold it right here for me. Rob, how often do you find you're doing a pie crusting to get a better view? Basically 100% of the time. Hold it there. Okay, so we're cheating here. We're going to the straight one just for the purposes of this demo. So, trying to get a good bite. A little bit more valgus, if you can. Did it grab it? Not really. Okay, do that one again. Alan's using the specimen later for a medial closing wedge, so I'm trying not to do anything to the medial side of the knee if I can help him with that. Obviously, I'd like to see a better gapping from what I did. Well, we've got a suggestion from Christian that I don't know if this is something you do if you're pulling the suture to bring the meniscus closer to you. Does that help at all? Yeah, it does. The problem is I've only got two hands. Can you pull this on the one that's not in the guide? We just got all the experts sitting here in the front row telling you how to do it. That doesn't look like the idea. I appreciate it. I'm still not getting a good bite on that. Okay, we're just going to pass it down without putting the second one in, just for the first one, for time reasons. One of the important things we found out is it's really important in these to make sure you don't get a soft tissue bridge, because the fat pad is going to win. Go ahead and put the suture up. Fat pad will win over pulling through the meniscus, so you have to make sure that you can get in there. Yeah, post your one. You can see we placed a nylon suture up it. You can use a nitinol wire, whatever works for you, to pass it, pulling it out the cannula. Hold the cannula in. Then we'll put the sutures in the nitinol and pass it down. So we'll get the first one passed in. Pull both down. Pulling it into place. You can see pulling it over. Optimally, I'd like to have a vertical mattress, but that's not going to happen. My preoperative planning wasn't correctly designed for this case. So tug on the stitch for me, the first one. Put the second one in. Let's shuttle it down. So Rob, you would normally do a second pass to create the vertical mattress. Is that what you're saying? You'd normally do that? Yeah, I'd normally put in a vertical mattress on it, David. I worry that if you don't have a wide force on these repairs, there's increased risk it's going to have it dislodge and pull through the soft tissue. So if you have a wide base vertical mattress, I think it's just a better way to try to make sure that you don't have the soft tissue fail. There's been a lot of publications that show that this technique here works fine with singles, but I think in the postgraduate world that we're thinking of, we're trying to do a little bit better job on repairing them. So I would do that, but it's probably not a big difference. I've got a question from the floor, Rob. What's the diameter of the drill for your tunnel? 2.7 millimeters. Thank you. There's the standard guard wire. Yeah, it's a drill with a cannula around it, so the cannula stays in place. See, when we pull the sutures, we get it back in, but I think you can see that with an arthritic knee, the tissue quality isn't great, and I'm sure if we pulled really hard, we could rip through. Looks like it needs an osteotomy. Yeah, it definitely needs an osteotomy. I think Dr. Amendola would be able to cure this knee, but that's the approach. So making sure that you have it above the osteotomy is key, making sure that your approach is first, so you can do that MCL release. Obviously, putting a little bit of valgus on with your hip is a lot easier than it could ever, so you can get a little better chance at passing a vertical mattress in. But those are the main little pearls that we do, and I'm going to turn this over to Dr. Amendola now. Good. Thanks, Rob. That's great. Just a quick question. When you go to fix it, how do you fix it, and what position in the knee do you fix it in? So we'll fix it at about 60 or 70 degrees in e-flexion. Remember that for those in the audience, the medial meniscus doesn't really roll back and forth very much. It's almost an extension of the medial tibial plateau, so it's not as critical to look at where your fixation angle is as it would be for a lateral root. Go ahead. Hey, Rob, we've got a question from the floor about centralization. Do you want to make a comment on that? Yeah, sure. And that's the postgraduate way of looking at these now, because we all know that when we're following these patients postoperatively with MRIs, that they're still extruding. So we're trying to figure out, do you have one centralization stitch? Do you have two? There's one paper I just reviewed for AJSM that had three centralization stitches, so we don't know exactly what the answer is in terms of whether that makes a difference or not. So I think the jury's still out on that. I'll do that for people that are chronic, especially for revisions. I don't do it for everybody because I don't think we have an answer yet. All right. Thanks. Over to you, Ned. All right. Thanks, David. And that was a nice job by Dr. LaPrade. It's nice to have a fellow prepare the exposure. So can we get on the screen here? Can we look at – no, just look at this surgical exposure here. We just need the camera on. And anyways, the incision, as Rob said, is just basically midpoint between the anterior crest of the tibia, posterior cortex of the tibia, kind of a longitudinal incision. And basically begin at the joint line and just come down towards the pes. And here I've inserted two guide wires, and the location of the osteotomy is going to be just above the insertion of the patellar tendon. So we've exposed the patellar tendon. We've got the Z retractor retracting the tendon. And then we've gone posteriorly and elevated subperiosteal soft tissues. And basically it's nice to have this type of elevator go behind. And it's really important to do a nice release posteriorly like this so that when you open the osteotomy, it'll open and you won't have a soft tissue bridge that's preventing you from opening the osteotomy. Now you can use one guide wire or two guide wires. Again, I'm an old style surgeon, been doing osteotomies for a long time. So I haven't moved over to the David Parker method using computer assistance. I don't have patient guides, but this is just a standard way of performing a basic tibial osteotomy. So if you look at the fluoroscopic image on the right, in terms of the osteotomy line, can we look at the x-ray? Is that on the screen? I think we've just seen the end of this guy. Now we've got the fluoride. All right. You can see the fluoride. I've inserted the two parallel wires. These are the two wires that Rob had inserted for the posterior root repair. Anyways, it's important to basically put the wires distally enough from the joint. You can see here it's about 2 centimeters distal. So when we do our osteotomy, we're going to go all the way across and basically stop a centimeter short of the lateral cortex. So then when we go opening up the osteotomy, it won't propagate towards the joint. Now you can use other techniques with a hinge point and everything like that, but I basically use the guide wires as a guide. Keep the guide wires on the proximal side of the osteotomy so it protects you from going towards the joint. Go about a centimeter short of the lateral cortex and then create the opening wedge. So Ned, you've put your guide wire just a little bit proximal and parallel to your osteotomy, right? That's right. Correct. So we're going to use a saw here to cut the medial cortex and then I complete the osteotomy with osteotomes. And again, as you mentioned earlier, David, you could do a biplanar osteotomy if you like, but here we're basically going with a microsagittal saw just distal to the guide wires, parallel to the guide wires. We've got a retractor posteriorly that's protecting us from the posterior structures. We've got a retractor anteriorly protecting the patellar tendon. And we're just going to go ahead and cut that. And you don't have to go all the way through. You can just stay within the safe zone. And then you can use thin osteotomes. This is a standard osteotome. You can see here it's a wide osteotome. I'm going to go again distal to the guide wires, keep the guide wires in place. Now these guide wires are up to the lateral cortex and are basically 70 millimeters. 70 millimeters. You can see them just exiting in the lateral cortex. So I know that I can I know that I can go in with this osteotome at least to 50 and probably 55 or 60 before I get to the centimeter from the lateral cortex. And you can see it just starting to open, the osteotomy site. You can see it just starting to open there. And so just take your time to complete the osteotomy. You don't have to go all the way across, but there's always the osteotome is always below the guide wires. So you do a fluoro shot for the guide wire placement and then do a fluoro shot when you think you're far enough with the osteotome. So I've gone in, I'm at 50 millimeters looking for a measurement on the osteotome. We're going to take a quick x-ray. And Ned, you got any tips for the audiences to how to make sure you get all that posterior cortex? Well, first of all, it's important to do the elevation of the soft tissues with the periosteal elevator. And then secondly, you go along the protective retractor, which is a homin. Here we're going to get a quick picture of the osteotomy. But that is very important, David. If you don't go far enough posteriorly, then I think that that's going to create some difficulties in terms of opening up. Go ahead. It's upside down, but it looks good. Okay, so we're on the right track. We're going to probably go another centimeter more towards the lateral cortex. Let's bring this back. So Ned, you're rotating it around this proximal tibiofibular joint and you're going into about five millimeters of the cortex. Is that roughly where you're going? Going about, I would say, yeah, just less than a centimeter from the lateral cortex. Okay, we'll put these retractors back in. But I don't do a lot of x-rays during the surgery. Basically, that's about it. Again, if you can see the osteotomy. And we're just going to go in another centimeter. And again, I'm on the posterior cortex, as you can see there. Again, emphasizing that's the widest part of the tibia. And that's the area that you want to make sure that you've gone through. So it looks like I'm about the right distance. And the osteotomy just starting to open up now when I stress it. You can see here the opening of the osteotomy. Ned, you probably mentioned this before, but with that soft tissue sleeve, is that all one layer? Periosteum, medial ligament, you lift it up? Yes, it's all one. It's going to go anteriorly a little bit. It's just like you taught me 20 years ago. Yeah, things haven't changed there, but you still have to expose it and do the osteotomy. All right, so obviously you can use any plate or any hardware you want and open this any way you want. We're going to do the eye balance technique. I'm going to take these two guide wires out. I think this is a good technique to use with relatively small or moderate size opening wedge osteotomies. You can allow early weight bearing as well. And you can look at the whole technique where you can use a hinge pin and so forth. I don't use that. So this is the cutting jig for the eye balance. And you basically place that into the osteotomy site. And create the lug holes. Put that in. Do the other one. And this implant is designed not to change the slope. So it's on purpose for coronal corrections only. I've been told I need to do a quick osteotomy, so we're just kind of rushing through this. You're doing great. What's your indications for using the eye balance system versus a standard locking plate? Well, I think it's... So here, again, you see the opening of the osteotomy. Basically, it's for just simple coronal plane corrections. Just simple coronal plane corrections. Somewhere under 12 millimeters at the most. But most of them are 9 or 10 millimeter opening wedge osteotomies. I usually don't use this for when I do combined surgery. So, say you're doing an ACL reconstruction at the same time, I tend to use a plate fixation just for more rigid fixation. This is a wedge opener. It comes with this system. So, we're basically just going to put that into the opening wedge. And, it's important to put it in the right location so it doesn't interfere with putting in your wedge opener or the implant. Yeah, so this technique, you can use a tuning fork as well. So, we just put one of the lugs in there to make sure this is centered. And, now we're going to do our opening. And, we had decided... So, can you see the opening there? Yep, we can see it. We're putting in an 8mm implant. So, here it's all open. You can put your bone graft in there if you want to use bone wedges or synthetic bone wedges. And, then take this distractor off. We're just going to put the implant in because we don't have any bone graft. So, it's opened up a little bit more than what the implant is. I'm just pushing that in. There's a little tamp that comes with the system. I'm just going to tap that in. There's our implant. I'm going to take this distractor off. And, this is a little bit tricky trying to get rid of this. So, can we get the screwdriver? You can disassemble it just like this. It just makes it easier. And, you can remove one limb at a time. It's a good opening wedge. It's a good wedge. I think that means you've got a very good hinge there, Ned. I think you're right. That's an important point for the audience. You want to have it opening nicely and easily. But, when you stop pushing on it, you want it to close. That means your hinge is intact. There's our implant in place. So, it's flush with the bone. And, I think this is a nice thing to do for small corrections. I think you can see here the wedge is closing by the time you get to the front. So, it's open at the back. And, by the time you get to the front of the knee, it's probably half the width of the opening wedge at the back. So, I think it's a nice simple technique. I think it's nice to use in active patients and young patients and athletes that you're doing minor or moderate osteotomies on. Okay, let's have the drill guide. So, this is a peak material. And, it has cancellous screws for the proximal side. And, the proximal screws are cancellous. And, they come up to a distance of 32 millimeters. You can see here. You're just taking them up to the subchondral bone unit. The proximal ones? Yeah, they sort of head to the joint on there. Yeah. And then, the distal screws go through the cortex. Alright. We're just going to go through the cortex and get cortical purchase. So, we're at 40. So, 44. I think you should tap the distal screws. We'll just put this screw in and then we'll take a look at it under fluoro and judge the osteotomy. See if we've created any problems. And Ned, just advice, you know, if you've done your osteotomy and you're starting to open it, and it opens a bit, but then it gets a bit harder to open it, what sort of checkpoints do you have for the audience to check before you keep pushing it? Well, I think, you know, the most common problems with doing an opening wedge osteotomy, I think, is not doing an adequate opening wedge because you haven't done enough of a release posteriorly. Secondly, is, you know, to, you know, make sure that you haven't increased the slope. Again, with this technique, it prevents you from increasing the slope. And, go ahead, try it again. There it is. Shoot again. So, it's pretty good. Again, this really demonstrates what we were talking about before, is if the distance to the lateral cortex is shorter than the distance to the joint, if you have to propagate and create a little bit of a cortical break, it's not going to go towards the joint. So that's good. And here's a lateral view. It looks nice. Now, Ned, I'm sure this is going to be a very hypothetical question for you because it probably never happens to you, but in the instance of a hinge fracture or intra-articular fracture, what would you do? Well, intra-articular fracture, I think you, you know, they're usually undisplaced. And I would just use cannulated screws and fix the intra-articular fracture before going any further with the opening and the fixation. After you fix the intra-articular fracture, then continue the osteotomy. Make sure you're further along so that then you can really, you can do the opening with the intra-articular fracture fixed. If you've got the fixation already in there and you have an intra-articular fracture, I think just putting in screws and keeping the fracture reduced, I think is adequate. In terms of a lateral cortical break, so as you know, some of the techniques and some of the companies that are here, they put a lateral screw along the lateral cortex to prevent a lateral hinge fracture. And I don't do that. But I think if you do have a lateral hinge fracture and you have translation, so if you look on this x-ray, when we did it, you could see the little crack going laterally. But there's no translation and no instability. So I don't think you need to do anything. Now if there is any translation, then I think it's unstable and you should probably go to a more rigid implant on the medial side and consider putting in a small plate or some fixation on the lateral side to recreate the hinge. So I would make a lateral incision and maybe use a two-hole plate or a staple on the lateral side and a more rigid fixation construct on the medial side, likely a plate. Great. That was a fantastic demo, Ned. Okay. Okay, we're moving on to Al now. How are you going there, Al? Are you ready? Yeah, we're great. Doing great. Thanks, David. Can you hear me okay? Yeah, we got you good. Start whenever you're ready, Al. Perfect. So we're just going to use exactly the same specimen. Which feed are we looking at, guys? Is it this feed? Right there. Yeah, so can you come focus right up on the distal femur? Okay, so the first thing we're going to do is just have a marker pen. There's one right there, Ned. So we'll just basically work out the approach. So this is a right leg. So I'm going to have the knee normally set up at about 60 to 80 degrees of flexion. I'm going to have a single foot post, and then a side post. I'm going to stand on the contralateral side with the fluoroscopy coming in from the ipsilateral side. I center my incision between the medial border of the patella, the medial epicondyle, and then it's going to be a straight incision basically over VMO. Okay, and so we'll get on and make our incision. So it's going to be a subvastus approach. It's really quite a nice approach to do for a medial closing wedge. You can see here already there's VMO fascia, and I'm going to split straight through VMO fascia. I'm not going through the muscle. Okay, now you can do this through a more minimally invasive approach, and I know Christian does that, but I think for when you start off doing a medial closing wedge, you really should make it a nice extensile approach. And then we're just basically going to elevate the muscle fibers off of the VMO fascia. Okay, and we can do a lot of finger dissection with this. And then I find my insertion more distally. We'll try and focus in there a little bit better because it's really important, this dissection. And I'm just going to basically incise the distal tendon insertion on VMO. Okay, and you're coming down then onto the intermuscular septum, and then I do blunt dissection. And you can see hopefully just where my finger is. I'm running my finger all the way along the intermuscular septum. Just pull your head out. You've got your head in the way there. Sorry, mate. That's all right. And then we can take a Hohmann retractor. There's one sitting on the tray somewhere. There we go. We got it here. You can see just past that Hohmann right underneath the VMO and lift it up. Okay, so that's the first. Okay, and then the knife is right here. And so we can just take the fibers off anteriorly. Okay, and then the next thing we're going to do is you really want to go down here with a cob elevator and do a blunt dissection off of your intermuscular septum. And this is a fairly safe approach. If you get too proximal, you're going to run into Hunter's Canal and you run into the femoral vessel. So obviously you don't want to do that. So it's about 20 centimeters proximal. I then do a periosteal dissection. And for this, normally I would use cautery. And you go straight onto the periosteum and you run along the posterior border of the femur. I'm going to extend that down to the metaphyseal flare. Okay, and in that position, I can then take my cob and I can go subperiosteal. Okay, and again, you're just running your cob all the way across back. I don't know if you can hear that, but it's really scratching on the bone. And so as long as I can hear the scratching on the bone, I can be happy with my resident doing this. And really I want to get to the point where I can put my finger all the way across the back and feel the lateral femoral condyle, the posterior condyle. Now in this scenario, what I tend to do is I take a Raytech gauze and I put a sponge. It's slightly smaller, but normally I'd put a sponge back there. Okay, and then over the top of that, I'm going to use a blunt omen. This is a sharp omen, but just you want to use a blunt. And it's ideal if you have the radiolucent retractors. And you can run this all the way across the back. You're right on bone. And now we're really nice and safe in terms of... What's there, Ned? Yeah, perfect. And so you should now be able to see. I'm just going to rotate this around a little bit. Okay, so now we can really see where we are. Maybe if we can bring the camera in a little bit more over my left-hand shoulder so you can really see. So the subperiosteal exposure is at the level of your osteotomy, right? Yep. Okay. And then your entry point, and Christian really highlighted this very nicely, okay, is that the more distal you are, when you take a wedge out, you're going to end up with a cortical mismatch, okay? The more proximal you are, then you've got a very oblique osteotomy cut, and again, you're going to end up with a cortical mismatch. So you're really trying to find a sweet spot where you end up with an equilateral triangle. And essentially, it's usually at the level of the supermedial vessels, okay? Now, you can't really see these very easily, but in real time, you're going to find the vessels there. You can cauterize those, and that's going to be about the level of my cut. Now, I'm going to plan out a closing wedge, and it's going to be a biplanar correction, so I can mark that out with a marker pen, and I can take... Hopefully, you can see this, and I'm going to do a proximal cut as well. You can see it when you don't put your head in the way. Huh. That's Amendola, by the way. I'm just saying. There's a bit of a clue. I know I'm losing a bit of hair, but... Yeah. Italians, they weigh about 50% of the time, right? So we're getting glimpses every now and then. All right. So what we're going to do next now is we'll put our pin in, okay? And so I normally go to my more distal pin first, okay? And I'm aiming for just about a couple of millimeters proximal to the condylar scar. Now, this is a threaded pin, which is never that easy, but we'll pop that in, and we'll take a look at that in fluoro. Do you mean the farsal scar, man? Not the farsal. It's basically the post of the scar or the posterior condyle. Okay, so if we take a shot there for me. Someone going to press go? We got a... Thanks, Rich. Okay, so for me, that is too proximal, okay? So I'll just take my drill, and I'll change that position. What's too? Is the whole thing too proximal now or just the end point? Just the end point. The hinge is too proximal. Shot there again, Rich. That's looking better. Shot. All right, so... So you're just trying to get just under that supercondylar flare, right? Yeah, shot there. All right, that's looking pretty good. Shot again. Lovely, okay. Now, when you look at that, you can actually work out that maybe I'll put my... That's a better position for my more proximal pin. So I'm going to take another pin, which we set up over here, and I'm going to take my measure. I just tend to use... Let's see if I can go and show you on this camera. Can you show me over here, guys? Just focus in. Yeah, I just basically take a little tape. So the measure that you would get off of the marker pen set, and I just cut that. So this is a 6mm correction, so I just cut that. And then I'll show you in a second. I'm just going to put this wire in, and I'll show you exactly where we went once we bring it back to the camera. Just watch your hand there. Shot for me. So that's two. And one thing you don't want to do is you don't want to have these two converging because ultimately you need to make sure that you can get your shot again all right so I like that because when you put your saw and your osteotome in between those two pins you're going to find that your hinge point is perfect if you have them absolutely perfectly converging at the at the hinge then you'll actually proximalize your hinge point you can end up causing a hinge fracture because it basically acts like a fulcrum okay so now the distance between the opposing edges of guide wires is six millimeters right say that again sorry the distance between the opposing edges of the guide wires six millimeters right yeah and I guess you have to think a little bit about the plate you're going to use to write in terms of that lateral point you need to leave enough room for your distal screws so I say that again so I guess where you're starting on the lateral side is affected a little bit by the plate the fixation you're going to use right the screw up where the screws are going to end up yeah yeah so we're starting here on them on the obviously on the medial side and and so depending on the plate so I can bring the plate in here and I can show you essentially where it wants to sit okay so but by and large by going with that positioning this is a sort of anatomic contoured plate for the medial side that you'll end up with four screws distally and then you'll have your screws proximally okay yep great so what I tend to need now is I'm going to just mark out again and I tend to use this with coterie and then and then I do a back cut so this by this concept of a biplane cut so I'm going to do my biplane cut first and so often you just got to get it started and then you can drop your hand okay and it wants to be at about a hundred and ten degree angle so hopefully you can see that and we're just going to run this there we go and then I got to drop my hand enough I'm going to finish that off once I've taken the wires out okay my next cut now is going to be perpendicular so it should be perpendicular to the femoral shaft and if we just bring the camera back a little bit nice little trick you can use is just the position of the handle of the saw so you want basically the handle of the saw to be to be parallel with the femoral shaft you know that if it's sitting off kilter like that then you know that you're not perpendicular to the the axis of the femoral court of the femoral shaft okay and so that now I also the blunt homin is sitting posteriorly so we're protecting our neurovascular structures we've got another homin sitting anteriorly protecting the muscle now I can actually do a lot of this work with my saw and I'm just going to run that along the posterior cortex and then the next cut again exactly parallel to that making sure that I don't extend the saw cut into your anterior flange okay so they're the anterior cut first and then I can come underneath my pins and now I want to basically run this along the posterior cortex that's already mobile all right so so what we should have is a nice little wedge that comes out just like that happens like that every time obviously well done beautiful you get a round of applause here and then and then I'm going to just try and finish off this anterior cut I'm probably gonna have to take my pins out to be able to do that to be able to get at it really important is that that anterior cut follows the direction of the osteotomy otherwise it's going to get hung up okay and what we can do now is we'll take an osteotome and so there's three osteotomes there and they're right underneath that so the anterior flanges is a pretty thin isn't it now it's thin it is thin and what I like about using the anterior flange is it really helps you one gives you an idea is whether or not you're creating any flexion or extension into your osteotomy but also if you do get end up with an unstable hinge it's not going to rotate off on you okay so you know you can put a tenaculum reduction force up across that plus and then as if all goes to plan and we've no unstable hinge ultimately at the end it's increasing your surface area for healing so you know I really that's a real go-to for me now with these osteotomes these are graduated calibrated so I can put this in now just for the purpose of time I'm not going to go back to the to the fluoroscopy because it's a bit of a pain but it's we're looking at about 40 45 so I'm gonna just knock this in gently hoping that I don't create a hinge fracture no I can I can feel using force use the force here okay and so the bioplanar is routine for you with these osteotomies that's routine yeah let's take those pins out now there was a pin driver somewhere now we'll probably talk about this a little bit in our case discussion is what you can do is you can't put a hinge pin in and there's a hinge wire that we can we can just take a standard K wire and we can run it from the meat from the lateral side and so if I just take one of those wires Ned thanks I'll just show you so you'd basically put it in can use pull back guys okay so you're right on on the femur and you're really trying to hit that apex of your of the hinge we haven't got it we haven't got the floor I pick no I'm not showing you floor I was just showing that it's sort of trajectory okay okay so you put put that pin at your apex of your two wires and then that's going to prevent or stop you basically in having your saw going like going out laterally and then as you open it up it should reduce the stress on your hinge I would tend to do that for for larger corrections I'm just going to take that saw again just so I can complete everything going on it's already starting to close okay so really important now with your osteotome is that you've definitely finished up your anterior cut so you can see here and this has got to go all the way through okay and that's pretty much gone all the way through and then I'm going to go make sure it's like proximally which it is and then if it's getting hung up you can see hopefully I can show you here it it's not that mobile just yet so I'm gonna have to put a little take a little bit more bone right what you can use and I use I have this routinely on my says you take a pair a set of Kerrison rangers so from the spinal instrumentation you know we used to do laminectomies as a resident and you can essentially take take those and that helps you take away posterior bone I find that really useful for lateral closing wedge proximal tibia osteotomy as well starting to get a little mobile and then I'm going to take that one of those pins again and we're going to busy just drill the far hinge how close do you need to get to the lateral cortex with the apex of yet yeah I want to be about a centimeter away and so now we're just drilling drilling the hinge trying to make a little weaker perfect absolutely so we would be taking shots as we go and it's slowly closing down there okay I'm gonna have to take a little bit more bone away and so then the other thing you can do and I do this a lot for my my closing wedge tibial osteotomies is just take an osteotome and score away across your osteotomy and just scoring away some of that bone okay it's then you can really feel your way across there yeah how about using a saw and kind of feathering the medial cortex do you ever do use that so as you are going all the way across with the saw no just feathering it a little bit so you go across of course don't break it but just kind of what you're doing with the osteotomes yeah instead just using the saw slowly up and down yeah you can definitely do that and the other thing you can do which is very nice is the it's particularly if you want to increase your correction you can close it you can close it down and then take a little bit more bone out with the saw but just bear in mind yeah it's starting to get a bit more mobile bear in mind that when you do that that you're potentially causing a little bit more thermal necrosis okay so I don't know if you can see this night can we just show that right in there we can see it yes yes mobile okay and it's just closing down nicely all right now would it be fair to say that just for the audience that when you're doing all this stuff you normally getting a bit more fluoro control 100% okay so it's just to give you an idea first pin goes in fluoro shot second pin goes in fluoro shot then I use the the oscillating saw I tend not to use the fluoro during the oscillating saw because the saw blade that I use is quite short it's only about five centimeters long and then once I'm going to the osteotomes I can put the osteotome in to about a centimeter short of the length of the pin that I've inserted then take another picture there okay and then under control you're bringing your osteotomes into the to your hinge point okay it's just the setup here is not ideal for going back and forth and we're a little bit tight for time so and we don't really want to run into our lunch but really what you can should be able to see there now is we've really got nice a nice mobile osteotomy site okay so the next thing we're going to do is we're going to put our our plate on okay so you can see the plate now sits and it sits fairly anteromedial okay and so and again I'm not going to fill all of these holes up so any tips with that distal screw direction now um yeah where you put the plate in relation to the trochlea in front and back I mean really to be perfectly honest with you I mean you want to be sitting fairly central one thing I tend to find is that most anterior aspect of the plate wants to ride really quite close to the trochlea so you got to be careful that you're not impinging onto the trochlea so you drop that back a little bit and then the other thing to do is make sure that the rotation of the plate is such that more proximally that it's still sitting on the femoral shaft okay but this plate it's fairly well it's fairly well contoured to the point where actually you can you know it really sits where it wants to sit and I tend to find that actually works fairly well and just another another question is if you hadn't done a biplanar and at this stage you notice that there was some displacement in the sagittal plane between your two fragments yep what would your response be so first thing you know again your setup you want to check your setup in terms of where the leg is sitting in relation to you know if you've got a lot of flexion built in then I would bring the leg straighter you can put some laundry underneath the distal femur so you really want to try and establish a neutral position that you're not putting an awful lot of load across the site okay then I would use a reduction forceps so I can actually place a reduction forcep anteriorly and capture the anterior flange and compress it I want to make sure that I don't have a distal sorry a hinge fracture if there's a hinge fracture particularly with a medial closing wedge bearing mind that that hinge fractures now on the tension side rather than a compression side I'm going to go and I want to put in some form of fixation on that now normally I just put a staple across it just to make sure that it's stable okay yep good so what we're going to do is just for this purpose of time we're going to go to the 3.2 millimeter drill so which I'd set up there where'd it go here it's here perfect and so this is now we're going to come to our compression hole okay and you can bring this then on the proximal aspect of hopefully you can see that guys can you okay that we're just going it's just standard AO technique going into the combi hole and then we're going to put in a compression lag screw and it's one of those gold screws there now that you just grab me on perfect and actually I'll just use this we just I've got it on power here now fantastic and so we're compressed it down and then we're just going to go in on power just until you reach the far cortex and then I'm going to go on hand and what we're looking for is just to compress that hopefully we get some decent compression across our osteotomy site okay and then it's just a matter of filling up the rest of the holes with locking screws so just use these guides what we'll do is we'll just bring it over and show what we've done okay hopefully it doesn't fall apart while I walk it across and someone just give me a quick shot there shot again and again and again perfect okay and then come on up so I can go there shot again okay so that's our medial closing wedge DFO and obviously we'd have four screws pro distally locking screws and then the remaining holes you fill up with locking screws and you can always switch out that cortical lag screw with a locking screw as well if you wish and that's it and how do you rehab these patients out so all my osteotomies I keep touch weight bearing for two weeks just until I see them and in clinic make sure they've got no wound issues make sure the radiographs looking good and if there's no issues then their weight bears tolerated thereafter you know we have a series of you know my partner Bob Litchfield has done you know a number of bilateral medial closing wedge DFOs and allows them to weight bear from get from the get-go you can do that I tend to be a little bit more cautious but certainly that our experience would be that a medial distal femoral medial closing wedge is much less painful than a lateral opening or any opening on osteotomy from that for that matter and so they tend to be a little bit more aggressive with rehab and I find them that they've done very very well and are you doing medial closing for all of your distal femorals just about just about I mean there will be you know scenarios where you know if you're thinking about leg length issues if you want to try and increase leg length then of course you can go to the lateral side if I may be doing a joint preservation case with an with a distal with a lateral femoral condyle OCA then you know you want to extend that lateral arthrotomy so it makes it easier to be on the lateral side I love medial closing wedge for patella femoral cases because one I can be on the medial side for my MPFL but also I'm not then causing more tightness of the lateral retinaculum and the you know the the tensor fascia lata and IT band which then you have to do further extensive releases and you know I've had cases where patient has had a lateral opening wedge done elsewhere and paradoxically increased their lateral patella instability because of that very issue so you know I think again the whole premise of this course is to not be stuck on one specific technique understand that the risks and benefits the pros and cons of individual techniques and then employ them for individual cases great well thank you to you Ned and Rob three great demonstrations we got Devin here as well he's one of Ned's fellows so I've been a great help so thank you Devin there's no wine from that so why does everyone now quickly break for lunch outside and then we're going to come back in here for a body cad lunch sponsored session so everyone get some stretching that was great presentation thanks everybody and let's let's get back here as quickly as we can

David Parker

patient-specific instrumentation

navigation

osteotomy surgeries

custom-made instruments

real-time imaging

surgeon

complex cases

chronic knee injury

medial closing wedge osteotomy

varus alignment

stabilize the knee

subvastus approach

guided pins

fluoroscopy imaging