Okay, guys, we're going to get started. This is meant to be interactive. We're going to go through three talks really quickly, about 15 minutes each, and then we'll go through some cases. And raise your hand during the talks. Again, this is an open dialogue. Dr. Gamal is going to start first on just traditional HTO and DFO osteotomies. Sorry, I need that Dunkin' Donut to fully wake me up. But thanks for being here. It's pretty hard to be here at 7 on the last day. So I'm the dinosaur. Speaking with these guys always makes me feel older, because I'm the one who just puts a pin in, cuts, and then looks. I just have migrated from the bovie court that I think Anil trashed, the bovie court. So I have a metal rod now. So it makes me feel not quite as old. So how to do it. This is all fairly self-explanatory. I just wanted to quickly go over how you do it. Obviously, you do alignment x-rays. And maybe I shouldn't say obviously, because there are some people who have the opinion that you can do all of this with just normal knee x-rays. You don't need a hip-to-ankle x-ray. I think that is a complete non-starter. You need to have bilateral weight-bearing hip-to-ankle x-rays to truly see a loaded view, because there's ligamentious instability, just as bony abnormality that plays a role into malalignment. So what you do then, you drop a line from the center of the hip to the center of the knee, center of the knee to the center of the ankle. And most modern PAC systems can do that pretty easily. Now you have an angle. And you know that if you correct that angle to 180, then the knee should be straight. You can transpose that. There are plenty of papers on how to do that. But that's really just basic geometry. What's I think a little bit more challenging is to figure out where you want that line to be when you're done. So that's that little picture here on the side. You want it neutral. Generally, you want not to overcorrect. You don't want to make them too abnormal in the other direction. But some pathology requires that. So let's say if you have someone who has perfect cartilage, but for whatever reason they lost their meniscus, but cartilage is intact, that person, you don't really need to make abnormal. You can make them normal. You make them neutral. Or you have a kid with a completely normal meniscus, normal tibial plateau, but they have an OCD lesion. You make them normal. That patient population, I don't overcorrect at all. On the other hand, if I see someone like me, maybe I lost my meniscus 20 years ago. And because of that relative meniscal deficiency, now I've worn down my cartilage and medial compartment a little bit. And I want an OCA and an HTO. That gets overcorrected a little bit, but not way into the lateral compartment. I wouldn't want that because I still want to be active and do sports. But if you are, and we don't do those much anymore. If you're totally bone on bone, you're older, in that case maybe you should have a uni anyways. But if for whatever reason you still want an HTO, that you need to overcorrect. So that's a little bit more kind of the old Coventry work. We really get into the valgus. So depending on who you are, what's missing, what you're substituting, that's how you pick your point. The one point, and that's a little subtle, and everyone who does this has been bitten by this. If you look at this young girl, she's clearly in varus on the left side. So she saw an outside physician who said you need an osteotomy because you're clearly in varus on the left. And if you look closely why she's in varus, if you look at her lateral joint space, it's not that she has lost medial joint space. It's not that she has congenital tibia vara. What happens is she had a post-lateral corner injury. So her left side is wider. So her instability or her malalignment is an instability-related malalignment. And in a figure of four position, you can see that she has an LCL, post-lateral corner insufficiency. So she's someone, not that you would never do an HDL on her, but you're really careful. A, you probably would reconstruct the ligaments for her, then see if there's any residual varus. And if there is, then you do a correction. But the correction will be much less than what this picture suggests. And usually, if you know that there is this difference in joint space opening, you want to decrease the degree of planned correction by about a millimeter for each difference. So if this one here is six on the right, four on the left, and let's say I had planned a seven-degree correction, then I would bump that down to a five-degree correction because otherwise post-op, when she stands in front of you, she'll be way too much varus. So just beware of that. Always take a look at your joint lines, and what you want is that the medial joint line is more narrow. That makes sense. If the lateral joint line in the affected knee is larger, then you've got to think about this. You can do stress views, and you definitely should check on the table where you press with just a linear force to make sure that the articular surface is all reduced, and then you can really judge this. So what type of osteotomy is open versus closing? We talk a lot about that, but it's almost universally migrated to opening, and why is opening in our minds better? A, because you're away from the perineal nerve, so it's a little bit safer, and you can adjust this intraoperatively. You make one cut, you open it to what you had predetermined, and then you take a look, and if that look is good, then you buy it. But if you don't like that, you can still open it more, open it less. A closing wedge, where you take one predetermined piece of bone out, you bought it a little bit. Now, you can make that closing wedge into an opening wedge, where you took out too much, and then you opened up a little bit more. So that can be adjusted as well. It's just not as elegant when you have to do this. And in terms of fixation systems, the really old first-generation non-locking stainless steel comparatively thin plates, I mean, you can do it. One of my old partners still uses them, but he's done osteotomies for 40 years, and he's not changing. But they're not very forgiving. If you don't do it right, if they have a little bit of delayed healing, you get hardware failure and it becomes a big problem. So I would say 100% of my practice is locking screws, and I haven't seen, I have seen maybe two hardware failures over the years, but that's really rare. And then this is just my technique. And like anything we do, if you do the right technique, you're careful, you know where you are, you know the anatomy, this is a very safe operation. As mentioned yesterday, there are sort of medial soft tissue strippers, cutters, and dissectors. I'm more of a dissector. So this is the PES. I take the PES off just like I would for a hamstring harvest. You see the MCL underneath. You cut the fascia, the posterior edge of the MCL, and then with pretty much blunt dissection, I do this actually usually with the NINA figure of four because you're looking right down. And with a bovie, you start taking the popliteus off the posterior aspect of the tibia, and because you use a bovie, the muscle contracts, it almost kind of pulls itself away from the bone for you. And you don't need much more than an inch. After that, take a cup. Don't take the brand new sharp cup. Take something that is a little bit more blunt. Stay on the bone. Don't plunge. You don't really have to do much. It's more sort of a gentle chafing. Give it another inch, and then the rest you can do with your finger. So there's really a pocket between the popliteus and the posterior edge of the tibia. You can find your way over. Once you feel the fibula head, you're done. And I usually put one malleable retractor, and I used to also put a sponge in. I don't really do that anymore. But that is a typical incision for an isolated HTO. This is one where you do intra-articular work at the same time. In terms of the height, people talk a lot about biplanar osteotomies. That's not a biplanar correction. That's really just, I'm cutting not just across, but I'm also cutting up. And in terms of the cutting across, I usually start at the level where I took the piss off. It doesn't really matter quite as much as you think. The fellows always ask, how do you choose your starting point? And I don't do very much dissection in the back. I really only dissect enough to get this malleable in. So that's your zone of protection. So when you put your pin in, then you put your pin in a direction that is protected by the malleable. You'll see this in a minute. And then I make this biplanar cut where the first thing I do actually is I do a cut just behind the tibial tubercle, almost like I start doing a tibial tubercle osteotomy and then I change my mind. And then I go down. And that has, at least in my hand, several advantages. One is you can be farther away from the joint line. You have more bone proximal because you can move your entire osteotomy more distal. By doing that, you have more bone. If you have more bone, there's less risk that your proximal bone fractures. And even if it does fracture, you have so much bone that you can put drafting screws. You have a lot of options. It's a different problem. If you're so proximal that you go right into the tibial plateau and you don't really have much space to fix that. So come across, then come down. That also, because that just slides, the bones remain in a position that heals really quickly. So now we have a healed bone bridge in the front. You have the plate more in the back. It's a more stable construct. This shows you what I meant before. So this malleable retractor with my limited dissection pretty much goes in only one way. And then you pick your starting point somewhere so that you're protected and you aim usually for the waist of the fibular head. That's the safest because even if you get a hinge fracture, as long as your hinge fractures at the level of the fibular head, you have capsule attached approximately distally, so you won't lose control over that piece. If you go lower, the bone becomes more sclerotic. You're not protected by that capsule. They can become quite unstable. And if you go too high, then you just increase the risk of going inadvertently into the tibial plateau. The front, actually at this point, I do the front and the posterior cortex, but maybe don't start with that. I use with a saw. You have your retractor. You always want to know where you are. And in the back, I finish. I take the malleable out. I take a osteotome. I put the edge of the osteotome on my finger, and my finger follows the edge over to the other side. And that doesn't only protect the soft tissues. It also tells you when you're done. So you don't have to take 1,000 floor shots because until your finger doesn't touch the fibular head, you're not done. And if it touches, you know you are done. Whether to use a staple or not, that just depends in my hands on the amount of correction. So if I have less than 10 millimeters, I never use a staple. But if this is someone who has a 12 or a 14, which is very rare, but if for whatever reason I decide to do that, I used to just make a little bit of a bigger incision, raise a flap, bring it over, and come lateral to the tibial tubercle. But then taking them out, everything is scarred. I ended up taking separate incisions to take them out. Now I just start with doing a small lateral incision. This goes just lateral to the tibial tubercle. And here you can see the cut is already made. Sometimes I leave the guide wire in because it makes it even more easy for you to see where you put this. You put the staple in, and then you open up. So this provides you a hinge. That always means that the hinge point is anterolateral. And if you follow the discussion about what to do and not to do about posterior slope changes, you want your hinge point to be anterolateral because that means you're not increasing posterior slope. I'm a big fan of stacked osteotomes. There are all sorts of gadgets how to open it up. But you put your first osteotome in, and that should be a proximal osteotome. You bring that in as far as you can because now you have the proximal tibial plateau supported, right? There's a hard support that lifts up, and then the next two and three go distal to that. So never start with a distal one and then add proximal osteotomes. Always start proximal, and that protects your bone. In this case, that's probably the biggest plate you possibly can use. I wish we had sort of a mid-size one. I tend to try this out with these wedges. So I open it up to what I think it should be, put the wedge in. They come in 5, 6, 7, 8, 9, 10. Then I do the bovie cord, the new version, bovie cord 2.0. That's a metal ruler. And get comfortable where that is. And you can still, you add more, you subtract more. By the way, do you see how the staple now is bent? So it is flexible enough to allow you to open, but it gives a little bit of compression on the lateral side, so that makes that heal better. And once you like it, you buy it. I use an allograft bone wedge. It's not that small corrections would need any grafting, but you need to somehow keep the gap open while you put the plate on. And the most elegant version I have found is if this is a 6mm metal wedge and I like it, I exchange that for a 6mm cortico cancellous wedge, put that in, and then I don't need any laminar spreaders, other spreading devices, I just, it's the bone in me. And it makes it much easier to put the plate on. And then the rest, if it's a larger correction, I fill it with something like demineralized bone matrix. But if it's someone you worry about, someone who's a little older, you can also go up. On the femur, this is someone who had intra-articular work done anyway, so it was an arthrotomy. It's just an example of taking an oats chisel, harvesting a little bit of autologous bone from the proximal medial, sorry, distal medial femur, and using that as bone graft. It's very accessible, cheap, and heals great. But I use that rarely. So what couldn't go wrong, that's a little bit of the horror show, but the nice thing with osteotomies is if you are aware of these, and you have a specific reproducible technique, that's not gonna happen. So this is someone here, for example, who had a osteotomy, ironically, in an ACL setting, and that ended up with increasing the posterior slope, I think increasing by seven degrees, so exactly what you don't want. And it's very easy to do if you're not careful. So what can you do? It's just positioning. When you position, you use a paint roller, you have the paint roller distal to the gastroc, and you have it up enough that the knee is essentially suspended, meaning it forces the knee into a hyperextension. When you do your cut, when you do a fixation at every step, there's a little bit of a tendency for the leg then to sag through your osteotomy site. What does that sag do? It extends. So you reduce slope by doing that. On the other hand, if you don't have a paint roller, especially if they're a little bit more of a gastroc, then the knee kind of flexes up, and it's the reverse. There's a tendency then to increase the slope. You also want to put your plate or that little bony wedge in the back. If you use laminar spreaders, you only use one laminar spreader in the back, so anything you do is you want to make sure that the gap in the back is bigger than the front. And this is sort of an example of what that should look like. It should really be a triangular space, with the largest being posterior, and as you get closer and closer to the tibial tubercle, your gap should get smaller. And by doing that, you can either neutralize or even decrease the gap, even with an opening wedge HDL. Lateral hinge instability, a lot of that, you can see little cracks. It's really mostly an issue with large corrections. I think this was a 14 millimeter correction. I would say every single one of them has a crack. So all you do is you address it, and ideally, before it happens, you put a staple in, because then you never lose stability of the lateral side. If you do a staple after the fact, that side, especially if it comes out, not in this case, but if it comes out down here, you can lose control over that lateral cortex, and you can get rotation, and that may be a little too exciting in the OR. So just do a prophylactic staple and nothing. You might not even realize that you blew through the hinge, and they heal just fine. And then fraction to tibial plateau, luckily, this is a rare enough thing that this is actually from when I did fellowship 20 years ago. That patient ended up getting two rafting screws. So we noticed that we closed it back down, two rafting screws. Then you have to carefully revisit your osteotomy, because the reason you broke in is that you didn't have sort of cortical perforation all the way around. And then it doesn't open easily, and then you do what, I guess, our job does is you ask for the bigger mallet, and then you open it, but unfortunately, it doesn't open up all the way over. This, you can still see a little bit of vertical split between the spines. And this one got autologous bone grafting healed uneventfully. So this is a recoverable thing. You just need to notice it. Vitamin has been super rare. I do check vitamin D levels, and I give almost everyone vitamin D pre-op. For larger corrections, for sure, high-dose vitamin D. I don't consider bone grafting for these larger corrections. I always stick some bone in. Usually, it's dead bone. And then the larger corrections, as mentioned, I also put autograft on. And the locking plate systems are definitely more forgiving. This was sort of a second-generation quasi-locking plate system, but this is an orthopedic surgeon from Brazil, and you really don't want to have that in part of your patient population. The one sort of final word on this, the arthroplasty surgeons have on occasion said, why do you guys play around with this stuff? Just do a total knee, and that's great. And if you do this, then the outcomes are not so great anyways, and then it compromises subsequent total knee. But Aaron Critch has done this beautiful study that I think you can only do in Iowa and Minnesota, where they found patients who ultimately ended up with bilateral total knee replacements, but also had a unilateral HTO before with 25-year follow-up. In New York, no chance doing anything like that ever, but the outcomes were not different. So especially with the newer techniques, medial opening wedge, there's less scarring behind the fat pad. So if you don't change the geometry of the proximal tibia very much, I wouldn't worry about subsequent, especially not total knee. I've done two unis after an HTO. That's a little bit more tricky, because you don't want to overcorrect them. So you just have to be careful who you pick, but it can be done. So if you don't do them yet, please do them. We see so many young patients who have ACL injuries, meniscus repair, meniscus fails. Now they're 35 to 45, have medial compartment OA, and are being told there's nothing for you to do until you are arbitrarily 57 1⁄2, and then we can do a total knee. And they can't play soccer with their kids. With this, they can. Thanks very much. Good morning. I see a lot of familiar faces in the audience, so thank you guys for coming and thanks, Leith. It shows you the world is changing, that NYU and HSS are holding hands in Kumbaya, so it's a good thing. Here are my disclosures. I am going to be talking about some patient-specific implants I am a consultant for. My task here is to talk, really, why everything that Andreas taught you is what I learned, and I always say that you never want to start your career with arthroscopic surgery, say, and not know how to open a shoulder. You've got to learn how to open a shoulder, you've got to learn how to open a knee before you become an arthroscopic knee surgeon, you've got to learn how to open a hip to be a hip arthrosophist. You have to learn osteotomy principles to then get to more advanced osteotomy principles. That's just surgery 101. And PSI is really a tool, but the tool is only as good as the surgeon who is using it and understanding the principles that Andreas really pointed out, because there are benefits of it in terms of accuracy, safety, reproducibility, versatility, but you still can make mistakes. I've made mistakes with regular osteotomies and I've made mistakes with PSI. So just because you have a tool doesn't mean it's guaranteed going to help you better, but if you understand the principles, it can definitely help you. And what it can help you with, it's make your time quicker, you can get even some cost savings by reducing revisions. Mike had a great paper about that. These are easily sterilizable and they can really move. And the benefits are obviously less radiation, less bleeding, interoperative time saving, increasing learning curve, and just giving you more data points in the OR. Understanding your wedge is really an important thing. You could do, I always tell the resident, if you ever have a difficulty sleeping and don't have an ambient, you read Freight Noises paper on opening wedge osteotomy and understanding tangents. It's better than ambient. That being said, we've all done it and we're like, okay, I don't take out my calculator in the OR, we always take out a ruler and PSI can really give you a lot more objective data to understanding how wedge affects various slope changes. So it's really a powerful thing. And the reason why is that this operation is not an average man's operation. That was really my task yesterday. I want to make this operation an average surgeon's operation, just like total knee is an average surgeon operation. The other thing also is an average surgeon operation is a partial knee. A partial knee was really not utilized 15, 20 years ago. If I asked the faculty how many unis they did as a resident, it would be not that many. We did total knees because partial knees were really hard to do. With the advent of new technology, specifically robotics, partial knees have grown tremendously. So that's enabling technology. So osteotomies need to grow tremendously, not just in hands of very skilled German surgeons, but literally, obviously, Europe has always been more of an osteotomy area, and we've always been much more pushed by the implant companies to do total knees. So there's politics here. There's bigger things. And now we have enabling technology to minimize complications and get better outcomes. And again, on the backs of our European colleagues. Because it's not just complications, it's also outcomes. This operation is a good operation, historically. It's a silver-level operation. We all have patients, like Andreas was just saying, where it's an amazing operation, where a patient's debilitated, and they're like, I'm playing soccer now. Steve Eiserman is the only player to ever get an osteotomy, come back to a professional level. He played in the NHL five years. And we're seeing this. We're seeing more aggressive intervention in higher levels. And we've all seen so many famous athletes who don't get an osteotomy, get an isolated carotid procedure, and you know what they also get? Early retirement. So we want to make this a great operation. Because we know it's a great operation when it's accurate. Accuracy is everything. And whether it's a Bovee cord, an alignment rod, a wedge analysis, and you're a master surgeon, you can get away with it. We want to give the average surgeon more utility, because we know that outcomes really correlate to the correct bony alignment. And we also know that when you screw it up, in terms of the sagittal plane, now, right? I have a patient, my first osteotomy I did increased his slope. He loved it. It was a failed meniscus repair, then had a meniscectomy, did an opening wedge osteotomy. He loved it. Did a tomofix. I thought I did a great job. Ten years later, he comes back, and he tore his ACL. I'm like, oh, slope's real. He loved me. I took his plate out and did his ACL revision. He was at that point 50-something. I got a revision of primary ACL. But my point is, we've all manipulated the sagittal plane iatrogenically, and now we're doing it surgically. So that's really a powerful tool. So here's a study that we did. We took a lot of people on this podium. We took four or five, I'd say, high-volume osteotomy surgeons, and we said, okay, let's do a tomofix versus a PSI. And let's look at a CT pre- and post-op, and let's look at, you know, we want to predict a wedge size from analysis, and we want to predict a medial proximal tibial angle. You couldn't get alignment, because even though it was a full leg, you know, they're not standing, so it's hard to say. But clearly, we know the PSI is better every time, and this is true for all enabling technologies. Whenever you compare a robot or navigation to the human hand, it wins in every sort of plane. When you're talking about a hip component, an acetabular component positioning, a tibial cut or an osteotomy, enabling technology will always win from a defined objective parameter. One of the things that we have to figure out, right, is that if you have a robot, if you have PSI, what is the right parameter, right? So I can tell you, when we started, I overcorrected a lot, and I'd say, you know, it's one thing that I'm sure I'd like to talk about. We're all probably, see, correcting a little less. So that's one of the things that we always want to talk about. Fuji Sawa isn't the gold standard anymore. That's just, you know, that's probably been overly talked about. And then we also know that, you know, in terms of this, it was, it really also reduced the outliers. So not only are you more accurate with the mean, right, enabling technology, again, this could talk, I could put a hip stem up here, it reduces your outliers. And lastly, it's also very good for radiation, radiation exposure, less x-rays. You just have more confidence in the system. But so this is not just about us. This is also about other systems. This is another PSI system. This is when Matthew Olivier was a traveling fellow, and he is an excellent surgeon, and he, you know, will tell you how excellent of a surgeon he is. But no, I'm just joking. He's a good friend. But he showed a really powerful thing, how PSI, and he doesn't even use PSI anymore, because he doesn't need it. He learned so much from PSI, he doesn't need it anymore. But he did show, for all of his trainees, it helps the learning curve, which is a powerful tool, which is, again, very consistent with robotic surgery. And it's also, and another group from South America has shown how PSI can help with x-rays. So when you hear one company, when you hear one paper from designer surgeons, I always say, don't trust that. We all saw that with, I'm going to pick on Oxford, when Oxford all said, 99 percent, we never have a failure rate. Then every told, every you need was done in HSS, the two-year failure rate for the Oxford in our early experience was 33 percent. It's atrocious. So be worried. But when you're starting to develop a body of literature from multiple companies, multiple independent reviewers, saying learning curve is better, radiation is better, accuracy is better, well, you know, maybe there's something there. So this is just one example of how it's really safe, you know, in terms of you put this guy to the bone, and then you have your slot. You can design, you know, from your preoperative template where, you know, where you want your hinge point to be and your hinge axis, whether you want to do a biplanar cut, whether you want to do a concomitant procedure. This is a really slick technique because it uses drill bits, so it's almost impossible to hit a neurovascular structure. It's very, very hard to break your hinge. You still have to use an osteotome, so you still have to be a surgeon because you could still break your hinge or hurt something with an osteotome after that. But the calibrated drill bits are a really slick technique, and it also doesn't hurt the bone. I think, you know, if you ever speak to a trauma surgeon, whenever they do a nonunion, they always keep the tourniquet down because they want the blood to help the bone. We like to move, so a lot of, you know, and when I first started this, I always used a tourniquet. I didn't use a tourniquet. Now I use a tourniquet because I want to move, but really keeping drill bits, which keeps the pressure, the exothermic temperature down, helps healing for an opening wedge osteotomy. Less critical for a closing wedge osteotomy. And the other cool thing about this is that you have an osteotomy in the box. You have everything you need. You have your plate. You have your laminar spread. You have, you know, you have everything that you need, and it's all sterile. And you know, this company actually has their own plate, and the plate conforms to the bone. I'm not saying this is mandatory, but it's nice. It's nice because there's a lot of different anatomy. A Tomofix is a phenomenal plate, and I will tell every young surgeon, you should start with a Tomofix. It's also a huge plate, so when you do a small female, they don't necessarily always like it. And, you know, last but not least, we talk about versatility. You know, it can help you with an ACL. It can help you with a sagittal plane. It can help you with a root repair. And now we're doing more and more double-level osteotomies. You know, in terms of understanding slope, and we could do a whole session just on this, to do an opening wedge, a pure opening wedge, and changing slope is hard to do. You have to have a small anterolateral head, as we've published on this, and it's hard to do. It can be done, but it really correlates to how large of a correction you need. Bigger correction, you can change slope more reproducibly. And that's why we're going away from kind of opening wedge or even closing wedge for slopes and more for the pure sagittal osteotomy. Oops. Sorry. And then, obviously, with an ACL, and I think there was a, this is actually a, I think this is Mike's case, from doing a concomitant with a root. And it's amazing. You have your root tunnels or ACL guides right in your guide. So it just, the pin hits it every time, as long as you put your PSI guide in the right place. Because when I used to do ACLs with osteotomies, I always staged them, because, you know, my screws are in the way, and there are other implants that have only two screws in the front. So if you take one of those, and the guys would just say, Tom D'Ambrobino, good buddy of mine, would say, oh, just take that screw out. I'm like, oh, you got one screw holding your whole proximal? I'm like, I don't like that. So here you can have all your fixation, miss your ACL, because all these screws are pre-planned to be around your tunnel. So it's kind of nice. And then now we're doing more and more double levels. And it's a pretty slick way to, you know, sometimes God, just like Andrea said, he cuts the hamstrings. The hamstrings were put there, the PES, to tell you where to start your osteotomy. God wants you to break the tibia. Just like he wants you to double-level osteotomy, because he wants you to take the bone from the femur and put it into the tibia for a big varus knee. So these are certain things that God wants you to do, so I always say. And this is really cool. You know, even if you don't fully believe in this, digital software planning, Al Getgood, who another master osteotomy surgeon, all of his templating is digital software now. You know, you're not going to go back to Etch-a-Sketch on paper. And there are a lot of PACS programs that give you stuff, but this is even fancier ways to get digital planning, because you get multiple planes. You can spin a CAT scan in multiple planes. So this is, actually, I'm just going to stop there, because, for the sake of time. But, you know, implementing PSI is not all positive. You know, you do need a pre-op CAT scan. Early on, there's increased time and cost, right? Bigger incision. We still haven't proven long-term clinical benefits. Just because Bob Hotchkiss, a very famous elbow surgeon at HSS, he says, sometimes evidence-based medicine isn't evidence-based. So we just don't have it. It doesn't mean we're not going to get there. We will. But I'm not going to come here and tell you we have it yet. But I'm fairly sure understanding the orthopedic landscape from learning from my father, and then seeing the last 20 years of myself, you know, this is an enabling technology, not a disruptive technology, as Kevin Bozic, in the terms of Kevin Bozic. And I really think the future of osteotomy is bright. It's going to grow, and it's going to get safer. Thank you very much. Thank you. All right, well, this will be the last talk and hopefully I think we'll present some cases after this. So I think what Anil and Andreas have alluded to so far is that the osteotomy is a great procedure and when done for the right reasons, for the right patients, the results are actually quite fantastic. One thing that's not talked about very much is how to convince a patient that they need an osteotomy. I mean, we, all four of us practice in a highly competitive environment and we all know how to do the right surgery at the right time, but, you know, trying to tell a patient that they need an osteotomy is also a trick in and of itself because, you know, when you practice in a high volume area where there's lots of surgeons, people fear what they don't understand, right? So they're going to see me, I'm going to tell them they should get an osteotomy. They're going to say, well, this dude's freaking crazy. So you're going to go to Gamal and Gamal's going to say the same thing, you need an osteotomy. Then they're going to find somebody who has never done an osteotomy and says, no, you don't need an osteotomy. That's a tool of the devil. Why would somebody break your bone? So, again, people fear what they don't understand. So I think PSI is actually really, really helpful because it enables us, as Neil was saying, there's that E word again, it enables us to talk to a patient with a little bit more, I would say, understanding and the patients will understand what's going on. Just like the MAKO and just like robotic total knees, people like when things are more patient specific. It kind of sets the tone in the back of their head. Something just perks up and then they become a little bit more of a believer. So I think PSI will also help us talk to our patients and explain to them why they need what they need and how we can do it better for them so that they have a little bit less fear and a little bit less hesitancy. So that's my, sorry about my digression, but we will talk a little bit about how to do these procedures in combination and how it can affect us. So I do have some consulting disclosures. I like metal for osteotomies. Metal is strong, metal is stout, metal is stable. Even set plates, although people love the idea of guaranteeing neurovascular protection in the back, they can get subsidence. If you don't put the plate into the right portion, the plate becomes the hinge, plate becomes your hinge, then you're hosed. You want stable fixation. There's principles of trauma 101, right? No trauma surgeon would ever be caught dead putting in an implant like this because they know exactly what's going to happen and why did we have to go through these failures to have this happen? It makes no sense. If you're going to do an osteotomy, use metal because it's going to give you your best outcome. Why do we use them? In the past, it used to be arthritis. Now it's a lot more than arthritis. It's for knee instability. It's for meniscus preservation, joint preservation, cartilage work, et cetera, meniscus root tears with significant varus. We all know that root tears from the data, if their patients are in more than five degrees of varus, that's a substantial failure indicator. Double osteotomies, as Anil was talking about, for big corrections that have a higher non-union rate. So double level osteotomies are a great tool because there's been some data out there that shows that most deformity, believe it or not, is bifocal. It's not just in the tibia. It's not just in the femur. So sometimes when you correct at multiple planes, that's going to give you a nice perpendicular joint. Andrea has also alluded to the angle of correction, Anil also. We used to correct at the Fujisawa point of 62.5%, but that's probably not correct for every different patient. Osteoarthritis is not the same as instability. Osteoarthritis is not the same as a focal chondral defect. For focal chondral defects, meniscus preservation, we tend to correct more to neutral. Patients don't tolerate overcorrection in the wrong setting. But finally, let's talk turkey, all right? How can PSI help you in your practice? As Anil had talked about, there's less radiation, intraoperative time savings. We've got lots of papers that are coming out that are going to prove this, as well as hinge protection. The hinge protection is somewhat of a big deal. I mean, if you've got a good plate, the hinge issue doesn't become as significant, but you never want to get a nonunion, particularly in the femur. Those patients don't do as well. We know that the cost is roughly the same, and we know that the accuracy is better, and we've shown papers that have shown this. If you want to look at our paper looking at cost, cost is entirely equivalent between a PSI system and a traditional freehand. When you take into account the six to ten cases, it's going to get to do the learning curve. So now let's talk about patients and care. This is a patient that had very significant patellar instability. She's in bed hanging out with her dogs. I'm glad the video isn't playing, because there's a lot of F-bombs that she drops. But you know, this is severe patellar instability, and she had that kind of terrible malalignment where the alignment line falls well beyond the lateral side of the joint. She's got elevated TTTG, a little bit of ALTA, a little bit of trochlear dysplasia, et cetera. So how are you going to correct this person? Tip tubercle osteotomy or trochleoplasty, it might not be enough. You might have to add a DFO or some sort of osteotomy into your armamentarium. It could be a medial closing wedge, lateral opening wedge. But again, you'll get your preoperative plan. It'll tell you how much you have to open the gap. It'll show you where the cut is with regard to the trochlea. And it will show you where your MPFL tunnel could or should be, right. So you can change the position of your screws to accommodate for an MPFL tunnel. That way you're not going to have tunnel convergence. You're not going to wind up hitting your screw with your MPFL tunnel, et cetera. And this is a patient that can do very well in the right setting and how you could use this to dial in. You can also dial in rotation with patient-specific osteotomy systems as well. So instead of just drilling 2K wires, taking a goniometer and trying to line things up in terms of your degree of rotational correction, this can all be dialed in to your preoperative plan and your preoperative template. ACL insufficiency with malalignment, we see it all the time. Little bit of varus, little bit of corner deficiency like Andrea was talking about. This patient had a foot drop, peroneal nerve discontinuity, it was a multiligament knee injury, little bit of increased slope. And you can dial in your hinge axis, which is something that needs to be talked about and needs to be discussed because the position of your hinge axis will determine your osteotomy and where things are going to open and it's going to help determine your slope. Traditionally, if we want to correct a lot more slope with an osteotomy, you have to really make that hinge anteriorly. It's very difficult to do in a freehand system. We can try, but if we fail, that hinge axis, if it breaks through, becomes very, very unstable and very painful. So we can align our hinge axis with a series of drill bits. You're not using a saw to basically break through the knee and cause thermal necrosis. And you can also organize where your ACL tunnel is going to be, whether it's above the cut, below the cut, et cetera. This system or these systems will allow you to place those tunnels and not converge with your screws. You can see how the screws are airing a little bit more posteriorly in this axial cut. And hopefully the ACL tunnel will come out in the exact correct position. Most of the time it does. You can do your procedure and get about your business. Meniscus roots are becoming very, very hot, right? In the past, they've seen us, but we haven't seen them. But now we are seeing them. And if the patient has too much varus and you try and correct their root or fix their root, then there's a high probability that this will fail, especially if the meniscus is already extruded. So this is a patient who is very active, had an ACL on the other side. You can see the patient's in about 7 degrees of mechanical varus. He had a meniscus root tear. And again, these systems allow you to place your screws in a way that will not interfere with your tunnel. You can see in the very bottom right, there's the meniscus root tunnel that's sort of dialed into the preoperative templating, into the template that you're going to use to place your osteotomy. Osteotomy cut is performed. And there you can see the drill bit coming out really very, very, very, very, very close to the anatomic attachment to the medial meniscus root. So the first time I did this, I was extremely shocked with how accurate it is. And every time I still use it, I still kind of get a little bit blown away because there's always play for error, especially when you're drilling a 60-millimeter tunnel and hoping for anatomic perfection. But I mean, these things can be very, very accurate and very helpful. Because in the past, you hit your screw, that's a 30-minute annoyance of trying to put your screws in the right place and get around them. Here you can see postoperative x-rays correcting to the lateral tibial spine. This patient did great. Large corrections. Large corrections are scary. They're scary for multiple reasons, nonunion risk, hinge fracture risk, et cetera. We also want to make our joint line perpendicular to the ground, right? If you've got a sloped joint line, the patient's going to have a lot more shear stress and failure. This is a patient with bilateral severe valgus deformity, osteoarthritis, starting in the lower compartment. She's like 35 years old, wasn't happy with the status of her knees. Here's her mechanical line. And you can see some of her deformity is coming from the femur and some of her deformity is coming from the tibia, as you would expect. And these are two possibilities that we can do, all right? You can do a distal femoral osteotomy, whether it's a lateral opening wedge or a medial closing wedge. But if you see, if you use an isolated distal femoral osteotomy, it's a huge cut, it's a huge correction, and it puts the distal lateral femoral angle at 96 or 97. The body doesn't want that, all right? The body wants things to be what they're supposed to be. Anywhere between 87 and 90 degrees for this is really what we're aiming for. So you're going to really oblique the joint line if you chose to do an isolated lateral distal femoral cut. The body does not like oblique joint lines, right? So if you change your plan and do a smaller correction in the femur and a small closing wedge correction in the tibia, that's going to make your joint line much more perpendicular to the ground. And the advantages of dual corrections, as Ranawat was saying, you can take bone from the femur and put it in the tibia or take bone from the tibia and put it in the femur. It's autographed. It's right there. There's nothing better than autographed. Because you're making smaller corrections, less risk of nonunion. Simple. We've addressed multiple planes of deformity. We know from Dror Paley and all the lines that we studied as residents, the ones that made us want to hit our head against the wall. When you correct it at the actual deformity site, that's when patients do better. We've got data to show that. And also when you correct it in the dual plane, it decreases the shear force on the joint. So again, we care about joint line obliquity because of the shear forces. If you screw around with the shear forces, you're going to get altered biomechanics. You're going to get altered peak pressures. Patients aren't going to be happy. We have data showing that patients aren't happy when you oblique the joint line. This is a good study out of Asia showing that if you oblique the joint line too far lateral or too far medial, clinical outcomes are substantially worse. So if they're about 95 percent, or excuse me, if the medial proximal tibial angle is greater than 95, those patients do terrible. Double level osteotomy has also helped with hinge fractures. Matt Olivier's group shows that hinge fractures decrease from 34% to 13% when you're doing double level osteotomy. It's because you're having smaller corrections. Smaller corrections equal less hinge fractures. Again, this is what you want to see. You want to see a perpendicular joint line. That's why dual level osteotomies are excellent, right? The bad is on the left. The good is on the right. We want the good. Sagittal plane alignment, which we talk about all the time now in ACLs. It's probably like the hottest thing you're going to hear. Everybody's talking about, you know, changing slope, slope osteotomy, slope osteotomy. Ten years ago, this was like no one ever even heard of it. It was still out there, but no one ever really talked about it. But again, as Andreas alluded to, the tibia is a triangle. If you put the gap in the wrong place, it's going to change the slope. So PSI offers us the ability to manipulate our slope through this. And again, as I said previously, if you want to change slope for medial opening wedge osteotomy, you've got your put, you have to put your osteotomy hinge in a very weird, very tricky position to do with a standard freehand cut. Again, this allows us to do this. Here you can see what they do with the drill bits. It formulates your joint, formulates your hinge axis. Different products are out there which give you different measurements, but again, they all work very beautifully. The purely sagittal slope-changing osteotomies are also great as well. You could do it above the tubercle, through the tubercle, underneath the tubercle, and PSI allows us to do this very accurately. In the past, we can, all this trans-tubercle technique, we could lift the tubercle up, you can go around the tubercle, et cetera. Bertrand Saint-Henri Quartet has described his technique, David de Jure's technique. It's pretty similar in France where they go above the tubercle to correct the slope, but now with the advent of PSI, we can do this quite easily. You could take a slope of 70 degrees or 20 degrees, however you want to think of it, which is substantial. This girl failed three or four ACL reconstructions. Plan is our closing wedge osteotomy, you'll get something like this. You see the hinge pin in the back. That hinge pin in the back is going to protect you. In the past, we used to do this saw cut from anterior to posterior. You take a saw blade and you cut from anterior to posterior, that changes the sphincter tone inside the room. Certainly decreases the sphincter tone inside the room, makes people a little bit more at ease, right? You have something protecting you in the back. You know exactly what your angles have to be, you know exactly how far you have to drill or ream or osteotome. What you want to see, something like this, you get a perfect lateral of the tibia and you can see that hinge pin going from medial to lateral. It's nice and posterior, that posterior bone. When you get nice and posterior, that stuff can be a little bit tricky, right? That bone is very hard in the back, so you want to get your cut close to the posterior aspect of the knee. Take out your wedge, shut it down, put your plate in, and you can see the slope has changed by about 12 to 14 degrees in this patient, so that's a win, all right? That's a win. And then at the same time, you can do your ACL reconstruction. These patients do very well. I've probably showed this video three or four times this meeting. I'm frankly sick of seeing it, but they do well. Seven days post-op, she's flexing zero to 90 with good quad control. Most of my ACLs don't have this kind of control at seven days. You can also manipulate your slope in the other direction, right? Chronic posterior cruciate ligament deficient knees. PCLs, everybody in this room, if you've done enough PCLs, you hate PCL reconstruction. You know why? Because they always loosen up, no matter how good you do it. No matter where you put the tunnels, they're always going to loosen up a little bit, right? And how much does slope have to do with that? Fair amount. Volker Musall and his group in Pitt show that the slope, if it's flat, those patients do worse. Those patients, gravity's not on their side. It's always going to pull the tibia down. So you have to think about osteotomy here for these kind of patients. This is a 31-year-old guy who failed a PCL reconstruction. I did his PCL reconstruction. It failed. The tunnels were in a good position. Alignment wasn't too bad. Maybe a touch of varus and his slope, but you can see it's not very good. You measure each plateau. One side was about two degrees. One side was about four degrees. That's not good for PCL healing. So our plan was to do a slope correcting osteotomy and just touch him into a little bit of valgus. We did an osteochondral allograft on his trochlea, which had a lesion as well. You can see it kicked him into a little bit of valgus, probably a little more valgus than I would like, but he's actually doing very nicely. His PCL feels much more stable. And then you get a message like this, dude feels 100 times better than it ever did before this last surgery. And obviously I wrote LOL on it because I know it's not his last surgery and he's going to get totally at some point, but I mean, you could do good things for patients. You really can. Hinge fractures. We already talked about it. Patient-specific osteotomies reduce the incidence of hinge fractures. I'm not going to keep talking about that. So in discussion, PSI offers us the opportunity to improve technical outcomes, maintains cost. Tell your people in Central Sterile or your cost committees that actually it's not going to cost them a lot more money at all. It won't cost them any more money. But again, probably the most important thing that you're going to hear today, if you do PSI, you have to understand osteotomy principles. If you don't, you're going to screw it up. You're going to screw it up. Understand what to do, when to do it, how to do it, how to protect your hinge, concept of stable fixation, and then you'll be fine. So walk before you can fly. Thanks. Okay. We're going to get into some cases. Andres, do you want to come up to the panel? So I think those are three great talks. From my standpoint, these are three great surgeons. I think for me, as an average surgeon, using the PSI technique, it made me a good surgeon. And I'm going to show you these cases. But how many of you in the audience do traditional osteotomies like Andres showed you? Okay. So most of you. Who's doing BodyCat or PSI? Okay. So a few. Yeah. I think if we haven't convinced you to do PSI after this, I think — you have a question? Yeah. You can finish your sentence. What's that? Yeah. You can finish your sentence. Oh. The — if we can't convince you to do PSI after these cases, I don't know what more we can do. I mean, you know, after seeing Andres' lecture, it made me kind of cringe. I hate thinking in the OR too much. I go in with a game plan, and it's go, go, go. And I think most of us are like that. And when something goes wrong, it's just a disaster for me. It sets me back 30 minutes like Mike brought up. Go ahead. And Neil, why don't you start with that? I mean, I think the learning, is that on? I think it's a few cases. There's no doubt. Obviously, you need the digital planning. I don't think you need to have, that's not, I mean, the software is profound. And so, assuming it's not a complex osteotomy, I think the problem that people do is that they use PS, they use general osteotomies, they do a ketone, they do their standard thing. And then they have a complex rotational osteotomy, then they want to do PSI. That, to me, is a little bit of a danger zone. I have a lot of fellows who do that. They're like, I don't need it for this, but then I try this. I'm like, well, do you understand what you're doing? So that would be my one, say, is do a couple easy chip shot PSI cases, so then you can really help to tackle the more complicated ones. But it's two or three cases, I would say. The European data says it's about six cases to seven cases to reach your max speed, right? Because remember, some of these are distal femur, some of these are proximal tibia, right? So each have their own guides, each have their own nuances. It's always tough to trust new technology. I mean, once I finally started doing this, I got so damn confident around here that I was like, look, I'm gonna put my finger around the back of the tibia and the drill bit's just gonna hit the very tip of my finger, right? And then you give it to a resident who skives off the bone and they drill right through your fucking finger. And excuse my language, I curse because it happens and it hurt a lot. So, definitely. There's a video of that. Yes, we have. No, it's on video. It's not fun to watch. But how much do you trust technology? The technology in this case actually works. Yeah, it's really trusting the residents. Yeah, well. There's some residents in the room, so. I still have a little bit of numbness. So the answer to that question is in terms of the learning curve, just like Anil said with the chip shots, the thing is the guide comes off at some point and you're using osteotomes to a certain extent. So you gotta fall back on some of your traditional principles of osteotomy. It helps the case get going. The other thing is when you do these combined procedures, the engineer does not know what the tibial tunnel length for your ACL needs to be. So you, especially if you're doing a bone patella tendon bone autograft and you need, so you don't want a graft mismatch. So that's where your communication with them comes in and where you start. But again, that comes after a couple of cases. So we'll get started. I'll show you something that I just got sent to me the other day. This is a case that I'm doing, which is ACL revision, medial meniscus transplant, and an HTO. So three tough things. Basically, real estate is minimized in that area. It's complicated. So, but now I'm less anxious about this. You have these off rigors when you see the 3.5 millimeter flip cutter guide. That's going to be for the posterior meniscus root where I'm going to dunk a bone plug back there. And then that 2.4 millimeter K wire approximately is for my ACL tunnel. So this technology enables you to do a complicated case like this, where in the past, I think I would have staged, right? Most of you, you know, something where you have screws going in different directions. So it gives you the ability to do a big complicated case that normally you would probably shy away from or stage. What's even slicker about that is that now they're giving you the options if you go back for your K wire versus a flip cutter. So, you know, because they're different diameters. So that's, I mean, we used to just give the K wire. Now they've, I mean, it just shows you how they can give us everything we want because they're two different diameters of safety. So it's just, it's a cool thing. Okay, so the first case, 24 year old female presents with chronic left knee pain, about six years, knee instability while running, no mechanical symptoms, no swelling. She had an ACL trans-tibial technique with hamstring. 2017, in 2020, she had another left knee arthroscopy. They said something about a partial re-tear, license of adhesions. She tells me her brother underwent multiple ACL reconstructions and multiple revisions. So she's obviously concerned. Her physical exam, she's got a varus gate, Lachman 2B, and a big pivot shift in the OR. Here are her x-rays. Anil, what do you think? She has a varus thrust too, you said? No varus thrust, she's just, when she walks, she's in varus, you could tell, compared to her other leg. But she has pain too, or just instability? Instability, and she has pain, but it's not well localized. Yeah. Um, I'm still gonna, you know, this is a tough one, because you could certainly make an argument to not treat the varus on her first time, you know, but look, she's got increased slope and in varus, so I would be, you know, and she's how old, 30? Or she's 24 now? 24. Uh. I mean, I know we're in an osteotomy conference, but, you know, depending, if she has an explosive pivot, then I'm doing a slope correction, osteotomy, and getting some of her varus out. If she doesn't have an explosive pivot, I'm doing a BTB with an LET. This is a tough one. Anil, I mean, Andreas, what do you think? That's my question, how much is the slope? Yeah, you can see on the plane x-ray, it was increased. I mean, usually, so there's one of these discussions that happens here at the podium, and then there's another discussion that happens in the patient room, and I often tell this. Well, that's why I said it was a tough one. Fellows come out of the room and present the case and say, what are we gonna do now? And then you say, I have no idea, let's meet the patient, because I saw this kid the other day who comes in who had failed one ACL, and he says, I heard about a slope-changing osteotomy. I'm interested in that. So if the patient brings it up, then that might be a situation where you do that for the first failed ACL, but the more commonly is they've been beaten down three, four, five times. But the other thing about this one is that she's kind of coming in that way, because she's saying, my brother was abused, right? So that's why this is, it's a hard one, because you can't just take, Andrea's point is that we're still clinicians, and you can't just take the x-ray in isolation. You gotta talk to the human. But it seems like she's asking to get her leg broken. Sometimes it's like you're talking to sort of a skittish horse. You wanna be low voice, and it's like, think about this a little bit, but because otherwise they think you're crazy, and as some of you had mentioned, then they go away and they find someone who does not good surgery on them, but it sounds less threatening. But for this one, if her head's in the right place, I would consider an osteotomy. Otherwise, it's an ACL with an LAT. But also, I mean, I don't see the, do you have a spot? See, I would get a spot lateral of none of the whole tibia and measure her ATT, and it looks there, it's hard to tell, because ATT to me is more important than slope, and if she's subluxed on her ATT, then I am gonna, you know, I don't know if this bat's not weight-bearing. Yeah, it's not perfect. Is that a weight-bearing lateral? No. So I always do a weight-bearing lateral and measure the ATT, but on your weight-bearing long leg, it's hard to see, it does look like her ATT's increased, and that's, you know, from Dave DeJure taught me this, he's like, that for him is almost, if you have high ATT and like marginal 12 1 1 1 half slope, he'll still do it versus, yeah, because that to me is the X-ray analogy of the explosive pivot. Right, and sometimes we get that on MRIs when they talk about the tibia being translated, and you may not have the right X-ray and they have a slightly increased slope, that pushes me to do a slope correction too. Okay, we'll get to, we got to some of the thoughts. So active young female, failed hamstring autograph, sagittal malalignment, some coronal malalignment, and a high-grade pivot. So I guess the question is for the audience, what graft are you using? So forget about the osteotomy for now. Who's doing quad? Okay, seems popular. Who's doing BTB auto? Okay, who's doing allograft? Any other grafts I missed? Contralateral hamstring, I've seen that done, which I'm not sure that makes sense. The only reason I would think about quad in this space is I'm presuming that they're gonna get a slope-changing osteotomy at the same point, which makes the BTB harder to do because of mismatch. So if I wasn't doing slope-changing osteotomy, I would do a BTB on this one. How's her medial compartment? On the MRI? I didn't put the MRI, it's fine. So whenever, and it looked like she has asymmetric varus, or was she? She had, no, asymmetric varus. So then I always worry about sort of this, what's her post-lateral coronary LCL look like? Because then, especially with planning, you have to be really careful that the engineer doesn't make her neutral, and you end up with an over-correctedness. It wasn't, if you could see here, it wasn't that much different, but it was a millimeter or two more on the other side. Can I just take a quick comment? Yeah. Well, I mean, you're just drag her in The reason why this case is hard is that you're giving me really high slope and you're not you're giving me not You know, it's hard to do this all with an opening wedge here. Yeah, so You know, you know, so this is definitely designed for a PSA because it's every time I try to do freehand I would be like, oh, yeah, I got him, you know I over corrected various and I maybe got two degrees out of Slope in reality for her It sounds like her slope is a bigger issue and the various is a secondary issue right from an opening wedge So here I would this is where you do play with your engineer and go show me what you can do with an opening wedge Let's also try a lateral closing wedge. See what you could do there there. You could definitely get more slope out so this would be a case I would think about doing a lateral closing wedge or Doing you know a pure sagittal and and avoiding the bear So, I mean we're doing from a pure sagittal do an asymmetric pure sagittal, which is hard I think for that, what you had said, a lateral closing wedge actually can give you both. Yeah, I mean, what Dave DiGioia and Matthew would do, they would just take more, a bigger, they would do, cutting from the front, just like asymmetric wedges, yeah, I mean, but, you know, that's really like. But you still have to disrupt the posterior cortex. Sure. That, to me, is important. See, these guys are way too, like, they're getting, my head's getting filled with a lot of things here, I'm getting confused, they're going into this land where I start to say, I'm not gonna do this case. And I think, but the idea is, you work with the engineer who's, and there's math involved, but you don't need, you just need to explain what you're trying to accomplish. And, you know, Anil brought up a good point. So, you know, for me, you know, well, we talked about, I wanna get to, we talked about this. Who's doing a Lemaire on this? Big pivot? Okay, fair. We talked about different graft options. So, great point. They came back to me, and this was a case I wasn't, I said, this is what we need to do. I wanna correct the sagittal slope. And they told me, well, she's got a little varus too. And they said, well, you can do both at the same time. You don't have to cut from front to back, like when we do an isolated sagittal slope. So it made me comfortable immediately that we can do some, a traditional medial approach for our osteotomy, which most of us are comfortable with. But they gave me this. They said, well, if you do a straight opening wedge, and I said, that's what I wanna do. You only get her back to about 12 1 1 2 degrees, you know, of slope correction. And you can get, obviously, more, you know, coronal plane correction. And that gets to, you know, Anil's point, that you can only correct the slope so much with a straight medial-based, you know, opening wedge osteotomy. But the beauty of this, right, so this is the second thing they sent me. They said, well, you can do an anterior closing wedge. And I go, oh, you know, I gotta worry about things. But they said you can do it through a medial cutting guide. I said, really? I can do it through a cutting guide? And Dr. Alea showed it in his talk. And this is kind of the concept. You play around with it, and the cutting guide comes medialing. You take this triangular wedge, and it allows you to correct both. You're essentially doing an anterior lateral closing wedge to get rid of some of the varus, and also correct the slope. And it's all in the guide. And I think that's the, you know, sort of value of this, and enables you to do everything in one shot. And this is sort of that, the cutting guide's medial. You got the hinge in the back there. So here's the hinge, right? This has to be cut. This is your hinge. And why does this have, the cut goes all the way back here? Because you're taking a wedge out laterally to get rid of the varus. And then the osteotomy comes here, and you're taking out more anteriorly to correct the slope. So that's sort of the thinking behind it. But when you go in the ER, you kind of want to avoid any major, you know, thinking. And that's the cutting guide. It's this, you know, trapezoidal cut where you're taking more out, you know, from the front and lateral to get your correction. There's that hinge axis. And you can see, in this case, right? The hinge is here, but laterally, we're taking it, going all the way to the back and cutting it. And I think that's where, as you get better, you know, with understanding this, the PSI is great. But you need to understand exactly what's happening in the case, so that when you start to try to compress it or do something and it's not working, you know, hey, I may have missed where I need to cut fully. And this was the ACL tunnel. I measured it out on the, I did BTB auto, you'll see on this, and I knew exactly what my tibial tunnel needed to be based on the MRI scan, in terms of, and I told them I need it to be this amount, and then they dialed it in. Andres, here's her meniscus and her medial compartment, so it looked pretty good. And that's her, you know, her ACL, you know, kind of stretched out and, you know, empty wall sign. Any questions? Yeah. Those, I'm thinking about separately. Hyper-extension, they can't give you because it's hyper-extension. They're just doing bone models, so actually they'll give you a sagittal that looks like minus 30 of hyper-extension, but it's actually not a true physiologic state. I would say to you, we had talked about this yesterday, I had a patient sagittal osteotomy minus 7 or 8 hyper-extension, I was scared, maybe minus 10, still did a pure sagittal plane and he did actually not change that much, and yesterday at the podium we were just saying, unofficially we polled everybody, who really thinks after a pure sagittal that they've actually seen an increase in record, we all think it will be, and none of us really had that problem. At least it doesn't translate degree to degree. It's not so much that the tibial plateau stays where it is, and you bring the leg up, it's more that you rotate... I don't fully understand it, but it's... In that patient I braced, I actually was like the first ACL I've ever done where I braced him in 30 degrees of flexion. That's what Dave Drew told me to do. Whether the post or capsule scar a little bit, but it was definitely did not get worse. Yeah. We've all seen that phenomenon where on the table it might get a little bit worse and then they come back for their first post-op, second post-op and you're like, where did it all go? Right? Now, ironically enough, if you have somebody with a flexion contracture and you do it, there I've actually, I've had one where I've actually seen it get a little better. So that's where I really don't understand. Patellar height is the other thing you had mentioned, right? Patellar height. You get a little bit of, essentially you force them into like a little bit of Ulta here, but by a hair, and that doesn't translate clinically. Patellar Baha is much more concerning. If you get a little Baha in your brain, for most of the time, or if you do it super... Super tubercle, they won't. The problem is if you're saying an isolated soft tissue procedure is even worse for that patient. So the answer is that we don't have the answer, but we're all telling you, you got to go for it. You can do a double limb or you can do a hyperextension on the t-band. You can't let them walk, you certainly can't. I let them partial weight pair pretty much right away. You've got stable fixation, and you get compression with every step they take. This one I'd be a little bit more cautious because there's a coronal correction. But a pure sagittal, ideally you want them to compress it. So you're pretty aggressive. But the goal of correction, Dave DeGiro is here, is you never want to correct to zero, right? You want to correct to five to seven, you know? That's, because if you correct to zero, you can go to minus five. My goal in this was to get it under 10. And I was limited by my coronal plane correction too, because I was doing that in the same setting. So that's what we shot for. It's 9.5 degrees in this case. This is just an intraoperative photo that you can see the osteotome going in, you know, behind the cortex. That's that lateral aspect where I needed to get through. So I knew that, and that was what was holding me up in the OR after I took the cutting jig off. But, so here's the case, right? Big pivot. And then I just do outside-end drilling. But this just kind of takes you through the steps in the case, so I think to get, you know, that this is all doable. And in terms of, you know, the approach, we're all comfortable with this. I take the MCL down. And then also, you go laterally, get the tendon, find that. And then here's the guide. And then you put a retractor. So I put a retractor in the back so it makes me comfortable. And then from there, I think you have all, you have your saw. It tells you exactly how deep to go. So for me, this makes this, you know, a much easier case. And this is me, you know, going towards the back, hyper-extended. You get this sort of picture. The hinge pin's there. Then there's these pre-drilled holes. Again, it's fast. You put the plate on. And then you have that outrigger. And this is the best part. I harvest the BTB. This is that outrigger. And you're always like, wow, it got into the right spot. Almost. Close. You know, and it's close to the osteotomy side. And then we did a LaMer on this. I think that was a no, you know, no-brainer, you know, for that. And then, you know, there's a shot of the ACL. I let a weight bear on it. You know, partial, and then gradually progress. And, you know, maybe I should have been a little more aggressive, because, you know, you get this shot. The slope's corrected, so it looks great. The coronal, she's in three, you know, almost four degrees of valgus to unload the medial compartment. The slope's corrected to about nine and a half. And this is her at eight weeks, right? A little stiff, not quite getting, you know, to 90. And then this is her at 12 weeks, essentially full motion. Great sneakers. Perfect kicks. Yeah, so that 70 degree tunnel, she's tall. So her tendon length was very long on the BTB. She's like 6'2". That's that. I mean, and the only, this is a case where it's a meniscus transplant. But the only thing I would say is that I don't open the lateral side for my pure sagittals, unless I was doing an asymmetric coronal plane, which this is a very nice case. Then I would, because you want to make sure you're asymmetrically getting there. But if you're just doing a pure sagittal, I don't think you have to open the lateral side. I mean, elevate the anterior compartment. Yeah. Just make sure that artery's not there. They talk about 2% like chance of having an aberrant anterior tibial artery, right? So just make sure you look at your MRI and make sure there's no little vessel sitting on the back of your tibia there. You can see it clearly. Right. So, the question with the guide is, it sits, and that was the one cool thing. They have the model of the tibia where it sits. When you put it in there, it sits flat where it wants to sit flat. If you start moving it proximally on the tibia or distally, it's not right. It doesn't conform, you know, to it. The second thing you could do is measure from the joint line if you're still uncomfortable and you're not sure it's fitting. But for me, it always seems to fit perfectly. And you have a picture of, with a K-wire, what it looks like. So, you have a model, you have numbers off the, and then you have an x-ray that, when they give you that package, the preoptive template, that we all put that on the wall, and you gotta make that look like that. Yeah. If you're gonna use PSI, sometimes the guides are a little bit thick sometimes. You're gonna have to take a little bit more incision. You can't do it through a small little incision. Like Andreas was doing, the freehand technique, you can make a smaller incision. But if you're gonna do PSI, you gotta make sure there's room for your guide. This was just the meniscus transplant, the first one I did with the guide. And we're all sitting there, and I'm like, no way is this gonna get through the right thing. And Mike brought this up. But you're just sitting there and you're like, wow. Goes right through the area. And that was, that sold it for me on this case. We're out of time. Any last questions? How many of you are gonna try it? At least give it a shot, right? What can go wrong? All right, thank you guys.

Patient-Specific Instrumentation

osteotomies

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surgeons' learning curves

metal fixation

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