alignment and patellofemoral pathology. So, Seth Sherman's gonna start with tibiotubercle osteotomy for patellofemoral joint osteoarthritis and instability. All right, Seth. Thanks, Ned. So, they always put PF next to complications at the end of the day, but it's an honor to be here. And we'll talk about when and how in 2023 my disclosures are available online. I would just start by saying when to do a TTO is frankly confusing. We wrote this article in AJSM and Fellowship, and I think we need to rethink it and rewrite it. For instability, at least, we know that isolated MPFC reconstructions, MPFLs or MQTFLs, are a true workhorse, even in the setting of risk factors like trochlear dysplasia. So, the real question is when do you need to do more? This is from Liza. This is a true jumping J sign. That will not do well with soft tissue type surgery. There's evidence to support this, and I use a lot. Apprehension into flexion. If you have apprehension past 30 degrees, 45, 60, this is likely more than just a soft tissue envelope problem. This likely represents altered dysplasia. More practically, combination of risk factors, including at the hip and the ankle, and we'll hear a lot more about this in the session. These require thoughtful pre-surgical planning. What does do more mean? There's a lot of measurements, and we'll go through them with the different speakers and in the cases, and a lot of different surgeries that we can do to tackle the bones to get PF right. And so, there's other factors, obviously, patient-specific, demand activity levels, insurance approvals, and the like. So, there's a lot of things here. This area is ripe for machine learning. Luckily, we're partnering with the Jupiter Group, which is collecting prospective data and working with our team, and hopefully, we'll have sort of a kneecap pre-surgical planner in the future. But I think a couple of points are valid. So, it's just old-school dogma to say TTTG greater than 20 equals TTO. Sadly, it's just not that simple. What is that TTTG really measuring? Is it femorotibial rotation? Is it a lateralized tubercle? Is it a medialized groove? Again, more practically, it's probably a combination of multiple of these risk factors. This paper showed that with TTTGs greater than 20, almost 50% did not have a lateralized tubercle. And so, we must be very careful. Maybe we use alternative-type measurements. We can't make TTO the hammer and everything looks like a nail. And Neil's dad taught me at HSS, the I see what the mind knows, and Liza and others are gonna talk about rotation, talk about valgus, talk about things that when we go across the pond, they're talking about for PF every single day. And in the American PF mindset, we have been a little bit late to the party. Here's cutting to the chase. TTO indications in 2023. I use intermedialization mostly to unload cartilage lesions. And then also, you can use it to correct lateralized force vectors for instability. Distillization we use for extremes of patella alta for both instability and sometimes chondrosis. And then we use TTOs in salvage, particularly for iatrogenic patella baja a few times a year. And we've been talking about it today when or when not to use TTOs in the setting of your slope changing type operations or HTOs. But the workhorse for me is for cartilage unloading. 97% of the experts in this paper agree that we should optimize the joint environment when we're doing cartilage type surgery in the PF joint. This is a infographic that I did with Jack Farr several years ago that I hope you find useful. But it basically shows you if you have malalignment, lateralized vector, and you have these distal lateral defects that we can do an anter medialization, shift the forces proximal and medial. And as John Fulkerson showed us years ago, we can get 87 plus percent good or excellent outcomes. Now compare that to this patient with central medial pan patella bipolar type disease. You can do and should do that same optimization of the bones. However, they won't do well if you leave it at that. And so these are the patients where combined cartilage restoration and realignment can get you up to those 80% good or excellent outcomes. And we looked in a big database study, and not surprisingly, if you add osteotomy to cartilage, we reduce the risk of reoperation, similar complication rates, similar overall costs. This has been borne out with cell-based repair strategies, TTO plus MACI or ACI versus just doing the cell-based cartilage repair alone. When we're doing TTOs for chondrosis, this is from OKO that I did with Brian Cole several years ago. You can keep the TTO unhinged. It'll give you great access to the joint for whatever you need to do. And then once you're done with cartilage, you put the TTO back and you do your soft tissue balancing and leave the operating room. And I've looked at this with my own series and reported on it. The bottom line is that the cartilage patients, the ones who need cartilage based on the indications I described, start off lower. They have pain between their episodes. They have mechanical symptoms. But sticking to these principles, you can get them to the same good or excellent outcome at the end of the day. Enterization can be used to decrease joint reaction forces. This is a biomechanical study that has shown this. We can reduce those forces 50%. Some of the previous techniques for enterization are challenging and can be fraught with complications. And so I'll show you a technique later in the lab which might simplify this. Here's a challenging patient to me. They have a symptomatic central trochlea defect. They're 40 years old. They have no measurable malalignment parameters, no instability. And so what are you gonna do? Are you gonna do a TTO enterization? You're gonna add a cell-based repair, an OCL graft? And I think we could debate this one, but for me, this is an isolated OCL graft. Whereas if I went cell-based, I probably would have added that TTO enterization. And those are different rehabs and different morbidity profiles. But I think it's an interesting case to think about. This is pretty rare, but patients with ALTA, with distal chondrosis, subchondral edema, that have failed extensive conservative treatment. This is not three to six months. This is like throw them out, shockwave PRP, anything that your non-ops can throw at them. But I have had success enterizing and distalizing this population rarely. And we distribute those forces more broadly on the PF joint. It's a big surgery, but I think it can affect change. When do we add distalization in PF instability? Again, this is controversial. Biomechanics, isometry or anisometry of the medial ligaments may suggest we pull the trigger as low as a caton de champ of 1.2. But I think most of us practically and clinically would not really do that until a caton de champ of 1.4 or above, although there are obvious exceptions to every rule. This kind of a case, I would not be able to solve it, in my opinion, without TTO, which would include antermedialization and distalization. We'll talk in detail about distalization-type techniques in a bit. Just to contrast with what I said about cartilage, when we're talking about pure instability, the principle is that we align the bones and then we balance the soft tissues, right? We cannot use an MPFL to push or pull the patella anywhere. Everything has to be lined up perfectly and then we soft tissue stabilize. So the order of operations is a bit different. Just wanted to point that out. Distalization can be humbling. We'll see some of those complications over beer later. We don't wanna over-distalize and create baja. I aim for a caton de champ around 1.1 so we can do some very basic orthopedic math, nothing like what Matthew showed us earlier. Liza's talked about not over-medializing and looking at what we call the tibial tubercle sulcus angle, which if you go to 90 degrees and it's zero, then you're likely not under or over-corrected. So I find that very, very useful and you can see that here. Kind of in summary for me, TTOs for PF instability is like a toilet plunger. It's a familiar tool and it solves the problems. It is not always getting at the root cause of everything patellofemoral, but it is certainly a workhorse. If you have patients like this one, she had non-contact right side dislocations at a young age. She failed a prior soft tissue surgery. She has apprehension up to like 45, not to 60 or 90. She has a subtle gliding J sign, not really a jumping J. Her patella height's normal. Borderline elevation of parameters, you're not really excited about fixing the trochlea, fixing any rotational abnormalities. We can get good results with well-done TTOs and soft tissue balancing and this is her on the one side and then her other side, which she's very unhappy with and required surgery for in the future. And so I think the evidence does support this, even if the lateralized tubercle is not always the primary deformity, we still, at least in these papers and in my experience and I think others, can use a TTO for a variety of combined risk factors. And then lastly, salvage. So this is patella baja, this is iatrogenic and I can show you in the lab tomorrow an easy way to correct this using a TTO combined with patella tendon lengthening. And I do this a handful of times a year when we have to. I think there's great opportunities for improvement. I've been fortunate to meet with and learn from Al Merchant. I'm gonna show you this in the demo, but this is basically his design concept, which is very different than the classic Fulkerson and the Elmsley triad and anything that we've seen previously. And I'll go through the advantages and disadvantages of his technique in a few minutes. Here's kind of a patient. They have bilateral recurrent patella dislocations. They have pretty much every risk factor, trochlear dysplasia, patella alta. They have a J sign, they have apprehension into deeper flexion. He has pain between episodes. He has significant patella but not trochlea chondrosis. And so this is one where I think we need a joint-preserving strategy. We do an osteochondral allograft. We do a intermedialization and distalization-type tubercle osteotomy. We do a trochleoplasty, in this case, just a Lars Peterson grooveplasty. And whenever people have big surgeries come back for the other side, I think it's a good indicator that this can work. And he had bilateral done over a three- or four-year time span. We're actively reviewing and publishing on this series. I have 75 to date looking at the novel technique that Al Merchant championed. And John Fulkerson's gracious enough to do head-to-head biomechanics studies on his AMZ versus the MD3T. And the most important thing for us is lifelong learning in patellofemoral. It's a humbling experience, and it takes a team and a lot of good mentors and advisors. So, Patellofemoral Foundation helps with this mission. And obviously, email me anytime to hash through cases. And thank you very much. All right, great talk. All right, we have the pleasure of having the queen of the patellofemoral joint, Liza Ernst, educate us on axial plane deformity and when to correct torsion. Well, it's late in the day, and hopefully, the patellofemoral joint will wake you guys up a little bit. So, again, I'm looking at trying to understand when to derotate, at what numerical threshold, and at what surgical technique. In the past, when we talked about patellofemoral things, all we could talk about was the tibial tubercle. But now we can talk about something different. Okay, so what's going on? This basically involves, I think, in my own mind, two things. When you're talking about femoral anaversion, what is its role in the J sign? And is it necessary to correct for cartilage health? I think the former is, we know that it does play a role. We don't know quite when to do it. And then for external tibial torsion, we do know it plays a role in pain. I think in isolation, I'm not sure personally what role it has in patella instability outside of when it's coupled with femoral anaversion. So, there's many ways to measure it. That's not the purpose of this talk, but I'll just briefly touch on the three most popular. When we talk about axial plane alignment, we need to look at femoral torsion or aversion, both retroversion and anaversion. Tibial torsion is almost always external, at least in our patellofemoral world. But I think that what we need to also include is this through-knee rotation, or the rotation between the femur and the tibia. I'm not sure if I'm moving this or not. Maybe. Okay. So, there are many ways to measure anaversion. You should become familiar with a technique that you want. It should be the same, and everyone in your institution measures it the same way. Talk to your radiologist. In our institution, we've agreed on a way, and only one of two radiologists read it. If it's over 30, we have both of them read it. Or you can do your own. But I figure radiologists get paid for something, so have them do it. So, this is a little bit controversial. The tibia is a little bit different. There's a couple of different ways to do it, but most people use the posterior. It is moving. Can you take the timing off of that? Sorry. Most people use the posterior tibia and the transmolecular axis. So, I'm so sorry. We did look with Al and our institution at a systematic review. This is normal, about 10 to 15 in the femur, about 20 to 30 in the tibia. And through knee rotation, again, is not much, but we do know that all of these are elevated in a patellofemoral joint or disease population. Gait analysis is helpful because it detects static and functional alignment, and it has no radiation. Hence, it's popular use in children. The negative part of it, it has a little bit lower accuracy for the hip. And of course, the cost is high. In our city, it's between $300 and $3,500. And the availability, of course, universally is not in every city. EOS is sort of the new kid on the block. As David Parker mentioned, it's a low-dose 3D imaging system primarily used by the spine surgeons. It allows for an AP and lateral upright image. And then you can model the 3D analysis as you want. The biggest advantage is that it has less radiation, less than 80% over standard. And it's something that you can use in your clinical practice. It's a costly machine, but once you have it, it has a lot of help. Now, excessive limb torsion, the classic person is this kissing kneecap. Just to bring a little bit of history into it, the Stan James was the one that first reported this in the United States, a very famous sports medicine book by John Kennedy, published in 1979. Now, I think that this kind of helps people, because in the literature, you're going to see femoral anaversion as well as femoral internal torsion. And you can see that in a normal situation, you have the toes and the patellas and the hips line up. But when you have increased anaversion, that forward-facing femur, to bring that femur underneath the pelvis, you have to internally rotate your femur. Then you've got a choice to either walk with your toes internally rotated or externally rotate your foot, and then bring your foot or your tibia, I should say, and then bring your foot to the ground in a pronated stance. That's why the miserable malalignment syndrome, which is more commonly seen in women, maybe because they show their legs more, I'm not sure, but we have femoral anaversion, squinting patella. And I put this in parentheses. It's apparent genuvarum and apparent tibial varus, and then, of course, the associated external tibial torsion and foot pronation. Here is an example of on the patient's left, you can see that you have that genuvarum and maybe mild, I should say, tibial varum and mild genuvarum on the left. And once their alignment is corrected, they have neutral alignment. I want to also mention that in long leg alignment views, I'm sorry, this is moving on its own. So you can see excessive limb torsion. Now, Christian talked about this. So if you have a long leg alignment view, you can see in our institution, we take it with the toes pointing forward. You can see here you've got the hidden lesser troch. You've got the tibia, the knee rotated such that you have the spine touching the lateral femoral condyle. And you can see that your ankles are pretty normal. Same patient with their patella is forward. You can now see the lesser troch. You can now see that the knees are more normal. You see those lines of the intercondylar notch. And the ankles are kind of funky. So I think it's important to have a consistent way to do long leg alignment view. And I like the long leg alignment views for everyone. So for me, when I talk about version of the tibia, it's excessive external tibial torsion without patella femoral instability. If you take a literature review, most of the time that you're doing derotation tibial osteotomy, it's for anterior knee pain. And then the second is patella instability. And less common is for a gait dysfunction or cosmetic deformity. In our own institution, this is just a brief two-year data. I'm so sorry. We had 23 patients. The CT measurements were between 32 and 50 degrees. Average correction, 22 degrees. And only three of those were for patella femoral instability. And I do have a fairly large patella femoral practice. Where to make the osteotomy? Everything is all over the place. I've been tutored not to do it above the tibial tubercle. We can talk about why. But the advantage for some is that it changes the TTTG. The negative is that it's limited in the degrees of axial correction. And you have to be a little bit concerned about, thank you, if you can stop the timer. The timing is on it. Yeah, can you take it off? So I can disable them. Yes, please. Transfer this past me. Thank you. And so you're limited to the degrees of axial correction. You have to be a little bit worried about trifurcation of the vessel and the peroneal nerve. And I think it's a little bit more difficult fixation. But these osteotomy guys might say I'm crazy. But just as Seth mentioned, that very first variable that you think you're changing the tibial tubercle, who cares about the TTTG? It's a worthless measurement. And the reason why is that it's made up of three things. The medialization, wow, so sorry. The medialization of the proximal femur in high-grade trochlear dysplasia, the through knee rotation, which we've learned about a long time ago by Settler's article in 212. OK, he's going to change this. Thank you. And so we do know about this through knee rotation. But we never really knew what to do about it. And we didn't pay too much attention to it. And the third variable is actually what people think they're measuring, which is the lateralization of the tibial tubercle, which, if you look in a patellofemoral population, is not statistically significant than normal. So I think the TTTG is correlated with patellofemoral instability, but it's not because of a lateralized tibial tubercle. Can you get me back on track? Mr. Audio guy, can you get the x-rays back up? Oh, here, he says yes. OK, and so I think, and then, so where do you do it? You can do a proximal above the tubercle. You can do it in the middle of the shaft, and you can do that with an IM rod. The advantage of it is that it's rather easy. The disadvantage is that you can get some irritation from the pins, and it oftentimes needs to have a fibular osteotomy. And then the third way is distally, and you can do it with a plate above the ankle. And this is often done in kids because you can do it without violating the growth plate. We can just go back on track, too. Can you get them back up? OK, so then, OK, there we go. That's the, so this is a lateralized tibial tubercle. So this is the midshaft with an IM rod and distal, which is often used in kids. Disadvantage is the plates nearly always are removed. Just a brief case presentation. This was a 22-year-old female, was told she had twisted legs, came with anterior knee pain. You can see that she had not significant internal rotation. The internal rotation of her hips was 60, external rotation 50. Everything else about her kneecaps were normal, but she did have kissing kneecap. And so here we have sort of briefly what I was showing you before. So she had the, you can see it really clearly at the knee level that they're internally rotated. When you put the toes externally rotated, they're better. And here you can see the ankles normal in one and sort of abnormal in the other. Everything else about her patella was good. This was her CT scan for version. You can see quite high in the tibia, not normal on the femur. And she underwent a tibial derotation osteotomy of 20 degrees with a fibular osteotomy. I just show this really early coup scores because they get better fast. So this I think is pretty remarkable. The quality of life in a lot of patella femoral issues is quite low, and she had great improvement in all. So for me, for anterior knee pain, I think that I start to think about it over 30 and definitely over 35. For instability, I really don't do it routinely in isolation unless I feel that they are having anterior knee pain that is unrelated to instability. Maybe a little bit hard to know. Now I'm just going to go on to about the femur. Again, just Seth, that's actually Dan Green's image that we borrowed from each other. We do know more about torsion now, done a lot of good work by Huan Feng, the late Huan Feng and his group. And we do know that it is associated with a J sign. If you don't correct, and they gave us a number, femoral version over 30, they don't do as well. Where to correct it, I'd like to have some discussion about it. I think that for most people, it's at the level of the surgeon comfort. We do have now several studies that show the version is at different places in the femur. I personally don't think that that matters per se, that you don't necessarily have to correct it at the site of the largest deformity, but maybe others will prove me wrong. One quick case, I'm just going to show a 13-year-old with recurrent left instability. She had what you'd expect at the knee for patella instability, no obvious valgus, sort of bad x-ray, I'm sorry. But you can see that she had femoral torsion that was more on the left, and her left was the symptomatic side, and tibial torsion to 39, femoral torsion to 34. And she was treated with a derotation osteotomy of the femur and tibia. And I'm just going to end with one quick one that showed the same thing. This was a person with hard J-sign, relocated at 15 degrees. Baten's was 4 over 9, but not at the knee, so no knee hyperextension. But she did walk with her knee in a flexed-knee gait, like a crouch gait, because when she went into full extension, she had the J-sign. And so this is very common that they kind of walk in a crouched-knee gait. You can see here that she had quite high values, including her patella alta. And so what we did was a derotated the femur and the tibia, and we did a distalization of the tibial tubercle. This, I know we can talk about different ways to do it. You do have to worry a little bit about how to get those screws in around the rod, but it does work. I've done it several times. And again, tremendous improvement in her KUS scores. So take-home message, axial plane alignment is an evolving risk factor in patellofemoral pain and instability. Consider femoral axial alignment when a hard J-sign is present. And for those surgeons with a complex PF practice, the role of complex osteotomies is growing. Thank you. Sorry for the mix-up. Can you answer a question? Sure. This is for everybody. Can you answer what percentage of your practice, patellofemoral practice, involves rotational osteotomies as your treatment? 15%. I would say that I don't get a CT scan on everybody. I don't use MRIs. We could. But I do CT scans on most patients. When they're younger, I do a gait analysis. So I probably get rotational alignment in about 40% of them. And I actually treat about 15% of them. So not a lot, but less than my trochleoplasties. Okay, and in addition to that, how many tibial tubercle osteotomies are you doing, say, now versus 10 years ago? Tibial tubercle osteotomies, more. I actually came into my patellofemoral world doing femoral de-rotation osteotomies. And this was the way I was trained, really taught by some of the Seattle pediatricians, the Seattle pediatric orthopedic surgeons. But with all of our concentration on hip and hip, you know, learning more about strengthening of the hip, et cetera, that went way down. But then I just started seeing more. And the reason I started in 2016, I would say from 2016 on, I've seen it. Maybe it was seeing me, but I've seen it more. So I would say in the last 10 years, a bit, but not so much before that. Thank you, that's great. All right, we're gonna have case presentations. And we're gonna do the same format. Maria Tuka is gonna present the first case, and then we'll have the group discussion and then group presentations. Great, thanks. So this is a case of a 15-year-old girl that's an amateur field hockey player, otherwise healthy, and that has a recurrent patellofemoral instability more than three episodes. Those are the x-rays. And the highlights of the physical examination, she has a neutral coronal and axial alignment, an increased Q angle, a Baden score of 409, quite marked apprehension until 40, 45 degrees of flexion, patellohypermobility, and a subtle J sign, not really a jumping J, as has been shown in the previous talks. And then now the imaging study. So trochlear dysplasia in this case, as we can see there, we have clearly a crossing sign, a double contouring, and maybe a little bump or offset. And we know this is quite controversial. The inter-interrater for this classification is pretty bad. So we could spend the whole afternoon discussing what degree it is. We grade it as a dysplasia type C, but we're not gonna talk about trochleobasis today, so this is not very important for the case. Anywhere I always measure the anterior offset or the bump of the trochlea, this is at the point that we see the ACL, but also if we go to the most upper and anterolateral part of the trochlea, there's no offset more than three millimeters. This is the Gatton de Champs of this patient. It's 1.51. And we always also measure this more functional engagement in the MRI, the patellar-trochlear overlap, that it's 38% that lies on a normal. So this is gonna be a topic that we can discuss also. The TDDG measured in the CT scan is of 21 on the left, 20 on the right that was asymptomatic so far. Remember that this is not interchangeable with the millimeters if we measure it in an MRI. That's always lower. And we also measure the TDPCL to see like sort of the true lateralization of the tubercle, that's 37, definitely high. Anteversion is 20, tiltortion 21, a 30-degree tilt. So a summary for the pre-op planning and to go for the discussion in the small tables. This is 15-year-old, so recurrent paraphernalia stability. That's the highlight of the physical exam as we've shown. And imaging, we see a high-grade trochlear dysplasia, a patella alta of 1.5, and a TDDG of 21. So the first round of questions, let's try to discuss about the indication. So do you agree that it's a good candidate for MPFL plus or less lengthening and a trivial tubercle transfer? And what will be your thresholds here for distalizing and medializing? And also let's discuss about the technique. So what type of osteotomies are you doing? What do you think are the advantages one or the other? The direction and magnitude of your transfer and the number and diameter of your screws. And here's like a little reminder of the probably most common options of doing your osteotomy. So that is the shingle that goes like flat at the end. This is with a transverse cat. And this is like the more new osteotomies that Seth showed are interesting to analyze. They are like a wedge. So let's go into the small groups. We'll have like three to five minutes. Just sensibility. No pain in between in the episodes. I believe that I do the tracheoplasty, subtraction. You do tracheoplasty? Yeah. But just for to do the congruence, not to do dip, because the cartilage problem in the future. But it's necessary, because if you just put the TTO and the ligament, it's not so congruent. That's a problem. I do the tracheoplasty for the congruence. Even with that small degree of anterior bump? Yeah, just not just the exam. You must look in the surgery if it's congruent or not congruent. That's a problem. Yeah, because if you put the patel in the normal position, OK, here, but you don't have the congruence to do the movement. Because it's so young, and for the trochlear to do the formation, you keep the patel in the correct position. That's so young problem. But you have three times, three times the pre-epsiles, you don't have more MPFL. Because you have three times, you have a long... It's just to protect, not to put in the articulation, you know? Because this, if necessary, if you put, it's not so good because it's not so... Thank you. Okay, everybody. So ready to wrap up. Yeah. Al, should I move forward? Great. So let's start with your table. So Al, what was the summary for, let's go for the question. So regarding the indication, did your table agree that it's a good candidate to add a transfer? We had absolutely zero agreement here at all. We pretty much had a massive fight. No, I'm joking. I think we, well, clearly there was some discussion about the trochlea dysplasia, and whether that features into our treatment algorithm. And I think we all agreed we'd look at the trochlea dysplasia and consider, but I personally wouldn't do a trochleoplasty. Maybe some of the other members would. TTO for sure was a distillation, and also because of the increased TTTG. Now, obviously the TTTG is increased partly because of the trochlea dysplasia, but also it does have an increased TTPCL. So probably medialization, distillation, and no pain, no chondrosis that you'd mentioned. So it probably doesn't need an anteriorization. And then the guys all said that they would recheck after doing the TTO to determine whether or not they would do the NPFL at the same time. And I think that would be worthy of discussion as to whether or not you always have to do an NPFL reconstruction in these cases, or you do it in select cases. Great. Seth, what did your table? Yeah, I think we came to a bit more consensus, it sounds like, than the front group. Obviously recurrent dislocator needs surgery. We felt that we need to do more than just the soft tissue balancing for the points that we made earlier that you brought up in your clinical exam. We clearly all thought that TTO medialization plus distillation, mostly distillation, makes the most sense. We didn't talk about it, but my personal bias is that we should add NPFL reconstructions or MQTFL reconstructions to these. I understand that now that we've fixed the bones, we can restore the resting length of the medial side and get away with repairs. It's probably worth revisiting, but I don't know that we're there yet. If the lateral side's tight, we do a lateral lengthening. We wrestled with the trochlea. In this one, we thought we could bypass it and not do a trochlear dysplasia surgery. And so we would save that lay crepe and save it for potential salvage if they fail. Excellent. And on the other side, so Rachel, your table there, so on the technique, what type of osteotomy would you prefer or like? You want to do a wedge? You want to shingle? Over the value or the lack thereof of the TTTG. And I'm sorry I monopolized the conversation because I just don't think it has much value. So that's what we were talking about. When do you medialize? When do you distillize? How do you use values? Sorry, didn't answer all your questions. Okay. And David, what about our table? What technique of osteotomy and how many screws so that we can move forward to the resolution of the case? We had variable techniques. We talked about a standard coronal plane osteotomy. We talked about a wedge-shaped osteotomy, which is what I tend to do and remove that distal fragments of technique that I saw Al do about a year ago in the lab. And some people fix it with two screws. I tend to use a little three-hole plate for the distalizing, not for the straight medializing, the little one-third tubular plate. And one screw goes distal and two through the fragment. And then I use a soft tissue anchor to put the patella tendon into the bed approximately, based on the French literature a long time ago talking about patella tendon length itself being an independent risk factor. So you reduce the length of patella tendon. Otherwise we agreed with, I guess, the general opinions around the room. Great. So we'll move forward so we have time to discuss some of the rehabilitation and imaging afterwards. I think it's interesting. So this is what we do. We distillize. Probably as Seth mentioned, we have shifts our threshold to 1.4. In this case, we aim to distillize 10 millimeters. That would leave a catondrochamps of 1.1. Same with medialization. Probably those that have more than 20 millimeters in the CT. In this case, we aim only to medialize 6 millimeters to get a TDDG of around 15. And also noting that distillization, because of the shape of the tibia, will also always have a small medializing effect. This is our preferred osteotomy. But the fixation, I do it with three 4.0 millimeters partially threaded bicortical screws. So we do compression with the partially threaded screws that go bicortical. And there are many studies I have tried to address how many screws we put in. Probably many of you use two. We use three because there's some studies that show that there's less sliding and gap formation and secondary displacement. So in these cases that I distillize so that we lose the distal hinge, I prefer and I feel safer in moving them around with three screws. So this is the result. So we did an MPFL reconstruction, lateral lengthening, and the distillization. And we achieved a catondrochamps of 1.1. So something interesting to talk on a second round of questions that we can have like maybe just a couple of minutes is how does your rehab protocol change if you add a tibial torus to the osteotomy compared to an isolated MPFL? And what I want to get to is how do you assess healing? So are you all taking x-rays? Are you using CTs? Are you using CT scans in some patients? When will you allow them to return to sports? Because sometimes we see this is a different case, but what if at six months your osteotomy looks like this? Would you feel happy of making them back to sports, contact sports? And how do we avoid a case like this one? So let's take a couple of minutes. I think that's what David just mentioned, yeah, that you're doing it, right? I am not, but... Yeah, that's what I was saying there. I do that because that's basically what Philippe Naret told me about 20 years ago based on their studies showing that the length of the patella tendon is an independent risk factor beyond the patella height. Does that prevent these complications? We have absolutely no data to back that up. No, I don't see how it would really. I mean, let's just take the stress off it. But I think the fixation here is critical, and the fixation dictates your rehab basically. But I think it does take some stress off the tubercle fixation, you know, doing the tinnitus, so I think it works. Yeah, that's a good trick. And what other tips or what other considerations would you have like on the rehab? Do you take a CT scan to assess healing or...? I think that's a good idea. I think it's hard to assess healing. Al, what are your thoughts on this? I like to avoid step cuts, so I don't like to have that cut because you'd be looking at a dreaded black line forever, so I basically feather it off. I also make a wedge sort of trapezoidal type cut, so I'm getting down into metaphyseal bones, so I'm not looking at a flat shingle. And that way, then when I take my radiographs, the film's never parallel to the plane of the osteotomy, so you never see it. And if I don't see it, I don't worry about it. Seth, do you feel like with the wedge osteotomy, you have faster healing or you feel more safe for the return to sports? I agree with Al's points. I don't tinnitus proximally, and I think there was a biomechanical study showing possibly aberrant increase of pressure, but I definitely think proximal buttress is critical, whatever you want to use, autograft, allograft. And I still am pretty conservative, more conservative with distalization than green stick AMZs or medializations as far as early weight bearing. And return to sport, they fall into line once I feel like radiographically they're healed. I don't get CTs, so I don't think there's a major difference between the osteotomy types for my late return to sport. Obviously, if I saw that X-ray, it would be different. I'd get a CT and have to start doing other things. So Maria, can I ask you on that X-ray, were you worried about the posterior aspect of the shingle healing or the inferior aspect of the shingle healing? We can see. I don't know how to show that. I'm worried about more the distal part of the shingle. And do you think that that's happening between interop and postop because of what? Do you think it's migrating? I heard somebody say you think it's sliding. You mean this one or the other one? The one on the third, the image. This one, right? The second image on the left. That one has actually fractured. It's a case that I borrowed. What I feel is that the immediate postop, you can see a sliding. So I imagine that intraop, they tried to compress the distal part of the shingle. I think so. So maybe from the immediate postop, I think that osteotomy has been sliding proximally. Why wouldn't you see that in the screws? Besides that, it has a fracture at the end because it never healed. The fracture's unfortunate. Minor trauma. It's like a fracture, a stress fracture. Difficult to know. I guess I'm asking, do people think, because that gap that you see distally happens often between the interop and the postoperative time. I don't think it's sliding because I think we see it in the screws. No. I think. And I think that it's some form of osteolysis just maybe because of the saw blade or something. Yeah, it might be. I'm just curious. This one's not such a good example because I can't tell for sure two of the three screws aren't bicortical. But I'm just wondering because I heard you say sliding. I'm not sure that that's why I think the gap exists in most cases. It might be that they'd never compress it really properly or that there's some necrosis. I really don't know. Only one comment. Look that lateral view. When you go with the distal cut, you go so perpendicular. It's not so good. It's better to go, you know. Flat. Yes. More flat for the interocortical because that's the problem with this fracture. The good thing about going on a transfer cut, as Seth shows, is that then you can transfer that part of it onto the proximal part. That could be making a bad choice, but I agree. So, well, we think this is a procedure that has low complications, but as this article lies, it's very interesting that we have a lot of complications in this procedure. It's like 9% bony complications, meaning fracture, loss of fixation and union, delayed union, and 10% of fibrosis that requires surgery. So I think it's important that we work on a rehab protocol here and we allow patients to return to support when we have evidence of healing. This may be x-ray or CD. And regarding the fractures that we have talked through, I try to make sure stability with three screws and compression technique in the osteotomy site and also in the district part of my osteotomy. Avoid thermal injury and make sure we have bone healing before we return to supports. Thank you. It means that I use a brace. I don't let them stay like in 030 for all the time, but since many of these patients are young patients that are not very adherent to your indications, when I do desalizations, I make them ambulate with a brace to make sure that the fractures we've seen in our group, it's because they have falls and during the rehab, fall on the stairs, and having them on a brace for ambulating, of course, doing passive range of motion. No, no, not logging it in extension, but maybe like a progressive, you go increasing degrees progressively, just as a protection for falls or like home accidents in this, they're usually teenagers. Okay, thank you. This case is a recurrent patellar instability with cerebral torsion. It's a female of 34 years, recreational sport woman, chronic patellar femoral instability and knee pain, and of course failed the conservative treatment. Physical examination and anterior knee pain, stress positive, big squat, no locking, some sign of it is good mobility and patellar femoral instability, but more pain than instability. Here, Q-angle is, as you see, as I can just see now, patellar instability is okay, and G-sign is positive, apprehension negative, slightly test negative, and please see the patient walk. This is the, the problem is in the left knee, this is the Q-angle, and I prefer this, the extend Q-angle to see the ankle, and the foot. The style is negative, no problem with the femur. Oh, sorry. I have this, this is, oh my God, I have my hair. This is the patient in the office, as you can see, the left knee, the left leg. Studies, x-ray, CT, MRI, here you have the x-rays. Sunrise view. This is a lateral view of the trochlear dysplasia. It's 162, I think, I don't know, perhaps a C. They have a 45 and tibial extra rotation, the left knee. No big problem with the height of the patella. It's a normal anteversion femoral. TTTG, yes, it's 26. And here, the circumference angle. MRI, you can see some osteochondritis. And then, in summary, it's the left knee, femoral anteversion is 5.8. The extra tibial rotation, 45. Circumference angle is 161. TTTG, 26. Patella, at this, 1.34. Certification. Why don't you finish the case and then we ask questions? Okay, perfect. Yes, yes. You're just behind. Okay, this is the possibility, the rotation of the tibia, TTTG, or the trochoplasty. We decide this. This is a picture of the scope. And we perform a tibial extra rotation. First of all, opening the proximal tibial femoral joint, as you can see in the picture. And then, we make all the osteotomy, and with the Y, go to the posterior cortical. Then we measure the rotation. When we have the rotation okay, we fix the rotation with this key wire. Then we perform the TAT, distalization and medialization of the TAT. And we go with the scope and see inside the knee if everything's okay. Here, the view of the anterolateral portal, pre and post. This is the view for the anteromedial portal, pre and post. And then this is the view of the patient, pre and post. And then fixed with a block plate. This is some view of the x-rays. And this is the final fixation. Here we have a video pre and post to see the configuration of the joint. That's all. Yeah, I think it's always an interesting one. I find it difficult sometimes to determine whether or not you should do a full rotational correction on the tibia or just do a TTO. And I don't know the right answer. And what I'd love to maybe do, I think, is to maybe get Christian to present his case, which is more rotational associated with pain. And then we're just going to have, and Liza's not going to present her case. We are running a bit behind. But then we're just going to have a general discussion about torsional correction. And really, we can then sort of do a little bit of a breakout, and we can talk about fixation and indications and everything else. Great. So, next case. I'm not on here. Let's go back. Oh, that's OK. It's coming. OK, so this is a case with patellofemoral joint pain and rotational issues. And Elizabeth and I, we haven't actually concluded on this case. But anyhow, it fits somewhat to her talk. And I've erased a couple of slides already to just win back some time as we run a bit late here. So, this 17-year-old girl, patellofemoral pain, since years actually, walking on crutches for years, having had issues a long time, has even been advised to see a psychiatrist and now sees the general physician for a fourth opinion because of her patellofemoral pain. That's her long leg axis. And obviously, that was taken because of her valgus alignment. And that's her CT scan showing a 45-degree external rotation on the left versus 22 external rotation on the right side. That's her gait. So, obviously, she seems to be nuts and was sent to a psychiatrist because of that, because she wasn't avoiding this kneeling in all the time. So, this is actually the measurements on the long leg standing film. So, you see all green figures. We've gone through that already. 86, 86, 88, 86, all looking good. The same as a table here. So, obviously, there is no malalignment as far as the frontal plane is concerned. So, what next? Conservative treatment, psychiatrist number two, anything else? So, we've concluded that we actually run through and don't open that for discussion now. So, obviously, there has been plenty of attempts to put everything into one big solution, like the missing link or puzzle piece that fixes everything. And in patellofemoral problems, obviously, as it's multifactorial, this is really an issue. So, this is a classification by ACOTO from the Hamburg group, and we've seen some other slides from them where they've put everything into stability issues, then morphological issues like soft tissue, patella alta, TTTG, genivalgum. Even the joint line is included into this classification. But, obviously, that adds lots of complexity and makes things sometimes even worse. So, I guess we can all agree that patellofemoral stabilizers are either static, passive, or active. So, bones, capsule, ligaments, or muscles. And, obviously, when we talk about osteotomies, then we can only affect the static environment there. And, obviously, we've spoken about tibial tubercle osteotomies already and so on and so on. And, well, the only one that actually affects the torsional deformities is the rotational osteotomies that we have here. So, you can address the patella height and TTTG and all that with tibial tubercle osteotomies. But, for this, we need rotational osteotomies. If we want to rotate something, first we need to know what to rotate. And, therefore, we need an assessment. And the problem with this rotational plane is that these deformities often go unnoticed because it's difficult to assess. The valgus you can see. Recurvatum you can see. But this is really hard to measure. So, you probably need imaging. But the first thing that you obviously do is you do your Staheli assessment. You look at it. You look at the gait. You look at the foot progression. You look at, in 90 degrees, knee flexion. Look at the mobility and the torsion and versional aspects of the femur. And then, obviously, of the tibia. So, and this is my good friend, Jörg Hara from Germany, who has these nice videos on the physical examination where you see these inwardly pointing knees here. If you straighten them up, then the feet point outwards. Obviously, you can do the same in sitting position. So, you have the knee flex at 90 degrees. You see that the patella tip actually here is marked. So, everything is marked there. And then, obviously, you do the same in prone. You can check for the rotation in the hip and the version in the femur. And you see the foot progression. And so, therefore, have an indicator in a fixed knee position on how the tibia looks. So, going further, this is a tibial exotorsion that caused the pain. Obviously, you've seen that in the measurements, 45 degrees on the left side. And the treatment for her was an internal rotation of her left tibia, completely normalizing her gait. So, unfortunately, the psychiatrist now is unemployed and has nothing else to do. So, there is the technical aspects of it, but I have a later talk on that. And so, we go through it in this later technical talk. Thank you so much. Thank you. It's funny. I guess the more complex the indication becomes, the more often that appears. And as we just mentioned, in this rotational plane, that happens quite often, that patients come to you after seeing three, four, five other physicians or surgeons. And the more obvious it all becomes and the more easier the indication is, the fewer that happens. So, frontal plane deformities are treated quite generously in Germany with osteotomies. These ones actually are tough because you first at hand don't see it. Second, you don't know how to treat it. Then you don't do a lot of those. So, this is why you don't have practice in those cases. And this is why these patients, actually, they kind of fall through the treatments. Your osteotomy was a little bit more distal than Rodrigo's. Well, we've spoken about the technical aspects. Actually, you've raised that also, Elizabeth, so that there is obviously different heights where you can do proximal tibial osteotomies, depending on whether you want to move your tibial tubercle with you or whether you want to detach it completely, whether you have an ascending or inverting cut for your tubercle. So, there is multiple options for that. What's the downside of going super-tubercle or proximal? Well, if you go proximal, actually, then you can rotate, leaving the tibial tubercle there. The question is, how far can you rotate? So, for some of those cases, you need to have a secondary wedge osteotomy for the tibial tubercle. You can go all the way straight for the biplaners. If you go upwards all the way, then you can freely rotate whatever you want. The problem there is, obviously, that you may have issues with the peroneal nerve. I will show you a technique for solving that issue because it's mostly not the common branch. It's the superficial peroneal nerve that is actually entrapped, not at the tibialis anterior, but at the extensor digitorum longus. There is the septum that divides those muscles, actually, and you have to incise that, and I will show you a technique in my technical talk. But, Christian, could I say that in the past, people were saying going suprapatellar because they thought that the tibial tubercle was so important. Yeah. But what is the advantage of going proximal? Because when I was being brought up in the osteotomy world, we were cautioned never to do it because of the potential trifurtication of the vessels, and if you did do it, it should be less than 10 degrees, maybe 15 degrees taps. So, what is your typical? Well, as I said, I just look at the position of the tibial tubercle. I shouldn't say typical. What are you comfortable derotating proximally, or it doesn't matter to you? It doesn't matter. So, if you have technical issues, then you actually need to tackle those. So, if you have a nerval issue, then you just need to know where the issue arises from. Or maybe you don't go proximal. I mean, I guess what I'm trying to say is... Well, you can. I mean, if you're going to go proximal, and then you have to release the nerve, why not do it at another level? Well, because maybe you want to have an influence on the position of the tibial tubercle and keep it there. You can obviously take it off. There is other advantages. The higher you go, the better the healing is. So, you can debate on many levels there, and obviously... What do you think? I'm just curious. How many people do derotation tibial osteotomies? Okay, and how many go proximal? How many go other? So, more than one. Well, I think it's really... You should have all of these treatments in your armamentarium. It's not like one technique fits all of your patients. No, I guess... I mean, this is a group that we're trying to bring... For me, I'd like people to be aware of tibial torsion. And if they see it and they want to treat it, maybe some of the pros and cons of how to treat it. I don't know why we got into IM rods. I was thinking of it earlier, and I think that it's because I'm highly influenced by trauma. So, you know, actually, Saheeli and Mark Swentowski from Seattle came in, and he's the one that got me off of using a lateral blade plate on the femur, and we started using IM rods. And then, I don't know why, we just started doing the IM rods on the tibia too. In the recent times, actually, and Matt, obviously, you may have a comment on that, you started to actually go to the distal tibia now more and more. Yeah, this was exactly my... I was trained by him doing Proximal and by Ronald Van Leeuwarden, removing the tibial tubercle, refixing it. And in fact, I just... Now, I really focus on the TTGT. If I have an abnormal value and I want to correct, I need to go Proximal to derotate and to have medialization of TTGT. But really often, they don't have any TTGT issues, so you just go to the ankle. It's a 10-minute surgery. No risk. Tiny plates, like ankle plate that you throw in the eye, you just derotate by 20 degrees. It's very easy. You never have to address the fibula. No, you don't have to address the fibula. Immediate weight-bearing. Compared to a crazy Proximal osteotomy that is very complex, I would say, for me, it's a game-changer to go to the ankle, if possible. If possible. So, Henry Ellis, do you do them? Where's Henry? I mean, this is what our pediatric guys always do. Well, I would say I like to go distal as well because of that exact reason. You know, to me, if I'm going to derotate, I'm going to go distally. If I'm worried about the tubercle, I'll do a tubercle transfer. So, I just haven't thought that it's worth the Proximal osteotomy. So, Liza sort of smiled there when Matthew talked about TTTG. And so, I'm getting from your talk that you don't think that TTTG is actually important anymore. And that even though you said that by 50, I don't know, you're doing more TTOs than anything else, which is probably distalizations primarily. But it still has been the workhorse of patellar instability surgery. It's still a big part of treating anterior knee pain. And so, you know, if you're dealing with someone who's got external tibial torsion, and you do have an increased TTTG, particularly if you've got an increased TTPCL, so it really is focused on the proximal tibia, surely is that not a good indication to rotate at the proximal side or the proximal end? Maybe. And I think that honestly, Al, because you've been doing it and you have done it safely, that has made me more confident that that may be okay. But to me, a medial tibial tubercle osteotomy is still an unloading operation. And unless there's something to unload that they have some form of lateral patellofemoral overload by MRI or x-ray or both, then I don't think it's so important. That's all. That's all. I think the more important thing in the derotation of the tibia is to open the head and diagnose the pathology. Then you have proximal, distal, in my experience only proximal. For me it's easy, it's not so difficult because you have in incision you have the tibial fibula joint very easy to take with a brush or whatever to separate only and then perform the osteotomy. The derotation is not so difficult. The more important thing is to diagnose this pathology, not refer our patient to the psychiatric. That's probably it and just a word, the last one and we just shared that thought, I never understood why there is absolute figures as a value for the TTDG actually because it should be an indexed value based on patient height. Once again, we come to the example of Shaquille O'Neal who probably has like 25, but for him it's actually normal. I remember there is a multifactorial pathology because in Argentina many surgeons only perform MPF reconstruction or TATs, no, the patient is a la carte. All right, very good session. I think we're going to go on to the next session. Thank you. Okay, one more before dinner. We're going to go on to have some surgical demonstrations. The first one is by Seth Sherman, he's going to show us a TTO. Are you there, Seth? Hi, Liza, can you hear me? Yes, we can. Excellent. Fire away. Can you see? Yes, we can. No, we can't. Okay. Yes, yes, we can. All right, excellent. I'm going to show you, hopefully we'll make up a little bit of time here, but we've had a lot of theoretical discussion, now we're going to take it practical using this system that I've used for over five years. It's designed by Al Merchant and what I like about it is that we can really do multi-plane correction with the same set of instruments and principles. So we'll start off just looking at saw bones very briefly, if you could do the overhead view. The way this works is either doing a primary wedge cut, which includes the patella tendon, or doing both the primary and a secondary wedge cut, and I'll show you that in a moment how we template the width of the secondary wedge. For the primary wedge cut, there are guides that I'll show you that we can basically make this kind of a configuration, and you can start to see how if you're just doing a pure anteriorization, how we can just take that bone out. We can use your bone graft substitute of choice proximally. We can put the bone wedge back in and we can get what I typically would do is like an eight millimeter or so anteriorization, and you can measure precisely, let me see if we can see the measurements, and we can rotate, so I can see exactly how much anteriorization that I may want to get, and then I can fixate this. So I think versus what I showed from that biomechanical study, that's a lot easier way to do anteriorization. Similarly, of course, you can do this type of cut. You can do any of the coronal plane osteotomies that the group talked about earlier, and then you can put the tubercle proximal or distal wherever you may choose. I think the most beneficial and what David DeJure was most impressed with this system or this concept is for distalization, basically that same primary wedge cut. You can take off only two or three millimeters or so of the distal cortical bone. You can widen what Al calls the kerf distally here, and that's essentially all that you need to do to create your distalization, and you can get up to that centimeter of distalization as we all talked about. We need to bone graft proximally. Here I'm using Play-Doh. In real life, I'll use synthetic bone graft substitute, but you can see how nicely this looks, and then when you look from the side view, as Al was talking about on our radiographs, one I think it's a stable construct, and you could wait for it earlier, and I think it heals reliably, at least in the series that I'm reporting on actively, but also the x-rays obviously in that lateral view look quite good. So that's the anterior primary wedge. We do the same thing if we're going to do intermedialization or AMZ plus distalization. We take the primary wedge out, then we create that secondary wedge cut, and basically we can just swap those positions, so the secondary wedge goes lateral. The primary wedge goes medial. We can measure precisely the amount of medialization. We can measure precisely that amount of anteriorization, and if you so choose, you can measure precisely the distalization. So I like that you can measure and adjust in real time in the operating room. For that one, you need to use this kind of a guide and the pretty standard typical ones and what we'll show in the demo. Basically if we have a TTTG, I know we've talked about this, that this may not be the best metric, but let's say it's 22 and our target is 10 millimeters of medialization and we want to enterize for chondrosis five, then the width of that secondary wedge is seven. We can also add distalization to the plan. When you distalize, it also medializes. So I think more important than this is your final assessment looking in that TT sulcus angle and making sure that you line up the putt before you leave the operating room. Hopefully that overview made sense. Lee, let's transition over to the cadaver and I'll show you a few things here. Liza, let me know if you can't see well. Focus Lee, distal here. So mostly on this part, maybe tilt a little if you can. This is a right... Can I just ask a question as you go through this model? So if you're going to do a medialization, you have to predetermine what that secondary wedge will be. But if you use a tubercle sulcus angle, you have to decide that before. So do you understand what I'm saying? And I know that you've said in many talks now that you use a tubercle sulcus angle. So how do you do that when you're deciding what... Yeah, I think I'd rather under medialize and feel like I've under corrected with my templating. And then I can always add two more millimeters medially and then check it again. So that's the way that I've compensated and I'm trying to figure, you know, right now we're whittling that away with a saw blade, but I think guide system for that extra two millimeters will be very helpful and hopefully will be coming soon. So does that answer your question? Yes. Excellent. So this is a right knee. This is lateral. This is medial. I'm not sure we're seeing. Yeah, I got it. Okay. The aerial view. You see it or not? No, no. There we go. Yeah. Now we see it. Good. So what I'm doing here is anterolateral, you know, obviously you can make a more limited invasive approach over the tubercle itself. That would be probably anywhere from six to eight centimeters. Most of the time I'm doing this for combined procedures. And so I'll come up to the level of the patella. I can do lateral lengthening through this approach. I can access for patella cartilage through this approach. If I need to do my MPFL reconstruction as well, then I will do the medial approach to the patella through the anterolateral incision. You can see how easily you can access that. And then I will also do a secondary smaller incision for the femoral MPFL. So with those kind of parameters, that's typical, but usually anterolateral for me. And so we'll go through the skin, subcutaneous tissue. Tell me if you can see the lateral side here. Let me try to rotate for a second and maybe get a retractor down here. So what I wanted to show you, Liza, is you have the IT band running in this plane. And then we have the superficial oblique fibers lateral retinaculum coming up. And basically if I'm doing that lateral lengthening to access the joint, I peel that superficial oblique layer down along the lateral border of the patella. And I've already done this. I'm going to release that. And I stay outside that second layer, which is the deep transverse layer, and the third layer, which is the capsular layer. And I can dissect down between those layers for about two centimeters. Maybe we can see here, this is my deep transverse and capsular leaflet. And then I basically, at the end of the case, I can suture those edges. So I can do a very easy two centimeter lengthening. As I said, with the tubercle unhinged, I can access the joint in its completion for any cartilage restoration type procedure. So I encourage us all to practice that tomorrow in the lab. In the interest of time now, we're looking down at the tubercle. So let's center Lee maybe on the hardware. We actually do have an increased Q angle or a lateralized force vector. We can also say we have patella alta here. We've gotten full control over the patella tendon. I like to be able to put my finger from one side to the other. I need access up above the tubercle in order to do this type of procedure. I don't want to mess with the fat pad too much. I release it from the back of the tubercle and let it float down posteriorly. And then what we did here, now I'm going to show you how to make that primary wedge that I showed in the saw bone. And so we have a guide that makes it very easy. Basically, I don't use a lot of fluoro for this technique. The maneuvers this side here is a lateral cortical finder. So I put that up against the lateral cortex. I push with my thumb and I keep my second finger above the tubercle. And that's how I set the primary guide. And so I can see here that it's lining up with my patella tendon. I don't have any patella tendon lateral. We can see that it's aiming down along the spine. It's not going too lateral or too medial. And so once I've set it with that lateral cortical finder, then you can use the primary wedge cut guide. And we'll see it here. And this, as you can imagine, can slide percutaneously under the skin. So really all the action is at the tubercle. And we don't need as big of an incision distally. We'll put this guide on. And as long as your patella tendon width is inside these guides, then we're good to go and we can start our cuts. If the medial side of that patella tendon is too large, then we can use an outrigger extender on that medial side to cut the medial aspect of the primary wedge. So we'll take that off. We did our saw cuts. I like to do the cuts with the larger striker saw, and then we'll go. I like to kind of use the TPS. Maybe we'll get the hall power back on. I'll use the TPS in line with my cuts just to make sure. And this really tapers distally to a nice triangle wedge cut. So I always kind of go over my initial A to P cuts with the TPS just to make it much easier for me. Now we're going to template, which we've already done, for the secondary wedge cut. And so we'll put on this outrigger. There are now very nice ways that we can see how big the width is. And so for this one, we templated eight. And we can place it once again. And then again, in the interest of time, we've made this part of the cut as well. And hopefully you can see that secondary wedge cut here. And it tapers down to the apex similarly. So we'll rotate around just a bit. You can see the primary wedge cut and the secondary wedge cut in that view. And so at this point, we're ready to do what we haven't done yet, is turn our attention more proximally. And so I don't know if this hall power is snapped in. Maybe we'll get it. Okay. So let's get an Army-Navy. This one first. So I think before we kind of start this part, I like to go over my tracks. You can see how we're inside lateral cortex. And I've dissected almost none of that anterior compartment. So I think that's a huge benefit also to this technique versus coming all the way down around the bottom and the back. I use the TPS, and I'll just kind of come up to above the tubercle. Just hold it like that, please. Not that crazy. Yeah. Good. So I want to come up just above the tubercle, envisioning in my mind's eye where I'm going to come across perpendicular. I'll do the same thing on the medial side. So I've kind of already set the foundation here, but now we're good to go. With smaller approaches and incisions, this obviously can be a little more challenging. This guide has some tracks in it. It's sort of an Army-Navy that rests just above the tubercle. We can use it to put our osteotome in the slot right above the tubercle. So someone will hold this guide just nice and steady, and hold the tibia, please. So I go in, and then I'll go across. Once I get most of the way across, I can look from the medial side, and I want to go to but not past that secondary wedge cut. So I'm pretty happy. Maybe I went slightly far on this one. We can also kind of backtrack the other parts of our osteotomy, and we should be ready to unhinge here in a moment. I'll take the larger osteotome for this portion, just make sure things are nice and freed up. Take the regular Army-Navy as well. I tend to use a bigger osteotome for this. Yep, let's use that Army-Navy. Here we go. Let's come just to the anterolateral aspect, hold that bone. So I'll go nice and gentle, just kind of trying to free up the top above our patella tendon. And we can see our patella tendon nicely, and then we'll come and work the anterolateral edge here, and try to just easily kind of separate that and get it to come out of its defect bed, and it'll be there in just a moment. You can see the lateral cortex is looking good. We try to preserve as much cancellous bone as we can deep. Can you see what I'm... Watch your hands, guys. So let's rotate around. So I basically just worked that anterolateral corner, and I brought this piece up. So now I have my nice tibial tubercle wedge. In this technique, I don't mind amputating it like this, so now I have a really nice tibial tubercle, pedicle, which is the primary wedge cut. If I have some bone in the bed here, that's fine. I'm going to use that. I'll just shift it over immediately. My secondary wedge cut can come out very easily. What is the length of that approximately? That's eight centimeters, and some don't like that length, and that's the way that it came. If you want to, you can use that guide up top, and you can taper it more abruptly, so you don't have to come that distal. For me, it hasn't been a problem, but that's something to talk about and to think about for sure. I think it's longer than our standard AMZ or other osteotomies that we're used to. At this point, we basically can clean things up, and then we're ready to change our positioning. I think one thing that's interesting, if we start here with this kind of vector, and we bring it medial and anterior, and we have our measuring so we can measure precisely, this osteotomy itself is not the pure translational. It seems to me as a rotational. I'd like to look more into that and see, especially with regard to the previous conversation, if it can compensate for some of those rotational aspects. I'm obviously not going to solve all those world problems, but this is a pretty straightforward thing we just did in five minutes and the morbidity profile sound, and I'm scared of some of the things I saw 20 minutes ago. Here is what I like about this. We can, again, measure precisely. This allows me to measure the anteriorization. At this point, I have six of anteriorization. I can go to eight if I need to, whatever my pre-surgical template is. I can measure precisely the amount of medialization. In this case, I have that 10 millimeters of medialization. In real time, one thing I don't think we touched on, you can peel up the periosteum distally and really minimal, cutting a lot of irrigation here. Let's take the ronger. I can take off a couple of millimeters of really just that cortical bone. Let me see the saw very quickly. So just widening that distal curve. Just a touch. The cortex is completely intact there. With just those little maneuvers, I can distalize basically eight to 10. I would have to work this a little bit more. Let me have that back. There's a little ridge here. Are we doing okay on time for the moment? Yeah, but maybe... Another minute or two. Well, at any rate, you can make that distal aspect. Let me have the ronger. Working this just for a few minutes, you can get the amount of distalization. Right now, I'm probably about six. I can get it to 10 and I can fixate it. So the next step will be to just use a K-wire fixation. So I get that you can do the distalization pretty well, but when you're doing an anteriorization, what's keeping it anterior? It's the screws that you're putting in? Yeah. So I think that's a clear drawback with cost concerns here. The technique that Al made mandates bone graft substituting, and Al went through a lot of different types, and for AMZs, there is a bone void. I think you can see it best here. Can you see this? So that's the primary wedge, that's the secondary wedge, that's a bone void that needs to be filled. So if you're doing a straight Elmslie triot with this, if that's something that you do, and you took a big secondary wedge, you can switch spots with the primary wedge and not bone graft. If you're doing an isolated distalization, you can just bone graft that proximal buttress. If you're doing just an enterization, you bone graft just behind it with your bone graft of choice, but with AMZ, that's something to think about, and that's really why we're kind of going head to head and working with John Fulkerson and seeing for that particular osteotomy, pure AMZ, if this is superior both in the OR and in long term, or equivalent or superior with more cost because of the synthetic bone graft. So that's certainly something that we need to be fully, fully aware of when you're considering this technique. Obviously, we can put also, see the secondary wedge does go in and provide some autograft bone as well, and then you bone graft the void here with your bone graft filler of choice. I tend to K-wire fix this. I don't know, Drew, if you want to do that. Just straight through. Hold the bottom. So once I get this K-wired, then I'll bring in my fluoro. So I really have only fluoroed at the front end. Go through that cortex. I've fluoroed at the front end, and then I fluoro at this part. I'll look with an AP. I'll look at my lateral view. I'll check my patella height. I'll look at my clinical Q angle, if I can detect that closer to extension. I'll bend the knee down to 90 and see that the patella tendon is kind of straight up and down. So in this case, it looks to me like it's looking pretty good and that we haven't over or under medialized, and then we'll use the bone graft. I tend to use two 5.0 headless screws. We don't have those here today for these cases, and that's reduced my rate of hardware removal. I know Andy Cascari and others have talked about three 3.5 screws. I know Maria talked about three screws, and certainly distalization is something where our radar is, you know, where we're thinking of more fixation. However, I think with the distalization here, that amount of distal stability gives me more comfort that I fix it very similar to my other techniques. So I think that's where we are, unless you have any other questions. Just a comment that you do have accelerated healing. I know you typically weight-bear as tolerates, yes? Yeah, I typically will foot-flat weight-bear for a couple weeks for, you know, just wound healing and just to generally let the knee rest. I come out of the, I brace them, I come out of the brace for range of motion right away, so that's passive motion, and sometimes using CPM depending on the complexity of the case, and then these patients start weight-bearing in that kind of three to six week range. I try to hold them off four to six weeks or more, but they typically do with their brace locked, and then I unlock the brace with quad control, discontinue the brace no later than eight weeks to usually a knee sleeve or a small patella stabilization brace. Great, thank you. Can you just tell me, tell us the name of this again? Yeah, this is the Kinemed MD3T, the multi-directional TTT system. And we do have a booth outside, just so you're aware of it, it's on the long corridor, just past the pop, the soda pop. All right, so we're gonna move on. The next two are going to be videos. The video will be Rachel Frank doing a distalization TTO. Nope, that's the end of the story. This patient's happy after this case, so we can just stop there. So, Rachel Frank, University of Colorado, I'm pretty humbled to be up here with the faculty that are here. These are world-class osteotomy and joint preservation surgeons, so thank you to the course directors for having me join. I actually video almost all my cases, and I do not have a video of my own distalization, so the video I'm going to show you in a minute, I'm going to steal from Dr. Clay Nuoli. Are we on presenter mode? Better, perfect, okay. So, and I did this in a case-based way, and we'll try to get done in under the 10 minutes. So, and you may argue with the indications for this case, as has been discussed in the last hour, because there's a few different ways to tackle this problem. This patient's a 30-year-old female. She came in, I'm sure we've all seen this patient, where another surgeon or two told her there's nothing that can be done. She came into my office in tears, barely walking, almost in a wheelchair, using crutches. She said that her dislocations in both knees started in her second grade, and again, she's 30 years old. She's had hundreds of dislocations in each knee. She's had years of PT. She has both pain anteriorly and apprehension, and she had one prior surgery and a lateral release in one of the knees done 15 years ago, but again, was told by the other docs that had seen her, there's nothing that can be done for your knees. You just need a knee replacement. 5'5", 140 pounds. This is one of those emotional visits. She's very tearful right from the get-go, doesn't want you to touch her knee. Very difficult examination. When you get her on the table, she's got obvious femoral anteversion bilaterally, patellofemoral crepitation with active knee extension, and it's difficult to assess her stability really, quite frankly, due to her guarding. No obvious valgus and no baseline ligamentous laxity. These are her AP, PA flexion, and patellar views, and you can see she's starting to develop some arthritis. Her angles don't look so bad when you look at these, but you can see something's going on on the AP view with respect to femoral rotation. You can see here on the right her patellar height as measured on CDI is about 1.45 to 1.5. On the left, 1.56 to 1.6. And then these are her standing radiographs, and again, very important to get these with appropriate technique with your technician, and difficult if the patient's guarded with standing. It's hard to correct for that. But certainly a concern for anteversion contributing to her patellar instability. So we send her for MRIs and CT scanograms and get a rotational profile. You can see on the right knee, the TTTG we measured at about 20. Her patella subluxated laterally. She's got some mild patellofemoral chondrosis, and for the sake of time, because this isn't supposed to be a case, but I made it a case, I'm going to zip through some of this. The left knee, very similar findings, slightly reduced TTTG, but a pretty bad patella cartilage defect with bone marrow edema, full thickness chondrosis of that medial facet of the patella, and some trochlear dysplasia that you can see. And then we'll kind of zip through her scanogram, but you can see on the rotational profile, she does have elevated femoral anteversion on both legs, and it is something to consider, because you could think about solving this problem with a derotation osteotomy versus what I ultimately did. And if we were going to have a case-based discussion on this, we would break out now and talk about what we would do. But I'll tell you what I did, and we offered her TTO AMZs with distillation on both knees, with MPFL reconstructions, with allograft, one knee at a time, of course. I would never torture her with both knees. On the right knee, because of the lack of significant chondrosis and the lack of significant pain, she did have pain, but it was more pain related to apprehension, didn't offer any cartilage work, but knowing we could always come back and do that. So this is her scope photos. You can see her patella is just sitting kind of outside the zip code of her trochlea. Her trochlea actually looks moderately healthy despite these hundreds of dislocations. This video is from Clay over at Missouri, and I'm going to play this here, and you can find the whole video. Sorry, I can't seem to figure out the mouse. Whoa, let's see if that works. You can find the whole video, I think, on arthroscopy techniques. But essentially, I do this very similar to how he does this, so I think this video is nice. And we've seen some demonstrations here already, and you'll get to play around this tomorrow in the lab. But essentially you center your incision over the tibial tubercle. This is not a minimally invasive surgery. If you can't see it, you can't fix it, and you definitely don't want to stretch the skin in this area by trying to keep the incision so small. That's where you can certainly get some skin problems. I like to make nice full thickness skin flaps, identify the medial and lateral borders of the patellar tendon, identify your tibial tubercle, and it's about a four centimeter to five centimeter V-shaped osteotomy going distally. And then you kind of have to decide how much you want to distallize. While we'd all love to get these patients under 1.2 on your CDI ratio, if they're that alta, you can't distallize that much. So Liza and I were actually talking about this in our group before, how much have you really distallized. For me, most of my distallizations are about 1 to 1.5 at the most, and so that's what we aim for in this patient's case. And then when you distallize, you essentially want to cut, and this is always the part of osteotomies that makes me nervous because I don't like to unhinge that shingle because we all know that that can lead to non-union and potential disastrous complications. But for a distallization, you have to do that. You can do this in a chevron fashion, but if you're going to add anterior medialization, you can't just move it straight down. And this is where we worry about wound healing problems, so you have to get a little creative with your cut. You can take the distal part of that osteotomy, cut it off the distal part, and then use that as bone graft proximally. But if you're doing an anterior medialization, which I was doing at the same time, that's typically not enough bone. And so I will use a tricortical allograft wedge in the proximal aspect of the osteotomy to add stability when I'm fixing this. So again, I think if you're doing a straight distallization, you can just use the piece of bone that you're cutting off so that you can distallize your fragment. But if you're adding anteriorization or anterior medialization, you do need to think about a more structural graft. Andreas and Sabrina and their team just published a paper on kind of doing a Fulkerson-type osteotomy with distallization and not having to add a structural graft. It just got published this year. That's a really interesting study to look at, or a technique paper I should say. And they seem to have good results. So I think there's more to come on how to best get these to heal, but healing is the main concern. Now Clay fixed this with two screws, but in my case I like to fix these with three screws. So this is actually her patient, or my patient excuse me, in this case on the right knee. So I like to fix with three screws. I use 4.5 screws times two for my standard TTOs, and then I'll add a 3.5 screw distally. Again, I really have a lot of fear about this not healing. I have not converted to headless screws. While I would agree with Seth, naturally there's a decreased rate of hardware removal. If you've ever had to remove a headless screw, it is the most miserable thing in the world. So I'd rather sacrifice a little bit of increased screw removal rates for ensuring that if I have to remove them, it's easier. It's kind of picking your complication. For me, I'd rather pick this complication. So you can see here on that first picture, you can see that hinge, and you can see where I've brought the patient down. You can see now her patellar height, her patellar, excuse me, her trochlear dysplasia is a little bit more obvious. And then you can see where we have our starting point for our MPFL. We do the same thing on the other knee about eight months later, seven months later, excuse me. She was so happy with the one knee. I wanted to make her wait at least six months. Number one, make sure we have good healing. But number two, make sure she's happy with the result because again, this could have gone a couple different ways. Could have worked on her from the femur and potentially solved her problems that way as well. In this case, because of her anterior knee pain and the known patella full thickness cartilage defect, we add an osteochondral allograft. This does change for me how I do my MPFL technique. And so instead of doing, I do a couple anchors on the patella for my MPFLs. But in these cases, I'll just do one anchor or do an MQTFL. So lots of different ways, but you've got to be prepared for managing the patella if you're adding a fresh cartilage graft. And again, same thing, three screws, kind of same type of fixation. And again, we changed our MPFL fixation in this case to suspensory instead of screw fixation on the femur due to adjusting how we did it on the patella. And again, these cases can be very rewarding. So this is shared with her permission with her photo there. If you're not familiar, in Colorado there's 14ers, so 14,000 foot mountains that you can hike. This is a woman in her 30s who was told that there's nothing she can do and she was essentially in a wheelchair when she came to see me. And now she's hiking up 14,000 foot mountains and she's super happy. And I think these cases can go well. This might not have been the right choice. If you asked all the surgeons in the front row, maybe they are second row or the whole room, maybe a different option would have been chosen. But this is one way and I think in these cases the distalization and the intermedialization are equally important parts. And that's just how I do my distalization. I think the key take-homes, especially for the maybe less volume surgeons in the room or the surgeons getting newer with osteotomies, you have to have stable fixation. So whether it's a one-third tubular plate, like Dr. Parker mentioned, or three screws or whatever you want, you have to have stable fixation. Because if you get a non-union here, that's a dreaded complication that's really difficult to fix. That's it. One thing I wanted to comment on, if you could go back to the MRI. Yes. You know, I think it's really important to look at where the load is or where your cartilage wear is. And with multiple dislocations, of course, the wear can be medial because we know when it comes back in it can injure the medial side. But then with overload, and she had an osteophyte and perhaps a little bit of lateral joint space narrowing in the patellofemoral compartment, but I thought I saw that the chondro-wear was medial. And so the distalization would have been appropriate, of course, to help with the instability. And the cartilage is hard. Sorry, I can't use my mouse when it's on. But you could, and I think that the cartilage is really hard to unload on the medial side, and therefore an osteochondroallograft may be appropriate. But why do an anteromedialization? Yeah, I think it's something I battle in my head all the time when I have especially isolated medial patellar defects, even without instability. And what do you do with those from an unloading perspective? And do you do a straight anteriorization, which patients often hate just because of where that tibial tubercle is? I think there is a potential for overloading that medial cartilage, but I'm hopeful with the distalization that her anatomy now will be a bit more normalized throughout a range of motion. But this could come back to bite me. You know, the good news is short-term follow-up's great, and long-term follow-up crushes all of our dreams. So I'm hopeful that this won't get bad in the future. You could say that stabilizing the patella will help to at least, you know, not for the progressive medial side, and it's obvious that she needs some lateral unloading. But I just think it's important to say, like, to look where your cartilage wear is and fashion your thought process for surgery accordingly. So that's a medial defect. And typically, AMZ unloads the lateral side. So this is kind of both. So I just wanted to kind of point that out. That's all. Any other questions? Okay, last but not least, we're going to have Christian do double duty here and do both a femoral external rotation osteotomy and a tibial internal rotation osteotomy with video. Take it away, Christian. Perfect. So yeah, once again, I erased some slides for the sake of speed. I take over the one from Al as well. He asked me to do that. Maybe we win back some time. And courtesy to Ronald von Herwaden here, obviously, who is a good friend and one of the great guys for rotational osteotomies and taught me a lot, discloses the same as before. Once again, rotational deformities, I've said that. Here's a slide for that. Often goes unnoticed for the named reason. And obviously, it's just a plane which is hard to defy. So what to me is really most important in this topic, it's actually like we have that from Paley for frontal plane deformities, is to really sort our nomenclature here. This is like which version of rotation in this torsion or is this torsion. So this is actually that throws all these words together and actually doesn't help you out a lot. And what it needs is a bit like here from the former speaker of the house. We need a bit of order. And what is rotation? So rotation first at hand is obviously dynamic. And it's an interchangeably used term for torsional deformities. And that shouldn't be as it's an umbrella term. And that makes things difficult because you throw everything into one bucket and then you just pick what you need. So rotation should be used for the dynamic movement version actually is the normal difference in angulation between the proximal and the distal part of a long bone. And it's a static description. And torsion actually is the version outside two standards deviation. And it's equally obviously static. So if we look at this here, then we have a bit of rotation. Hopefully that plays. Yeah, that does it here. So this is obviously rotation. Yeah. Then this here is the torsion within the bone. Sorry, that's the version within the bone and then it torques. And that is what you can see in the last one. So that is the order that we need for that. Yeah. So the problem now is that throughout our adolescence, that equally changes. So there is standard values for antiversion or femoral antiversion or tibial version. And actually that changes throughout your adolescence. And therefore you once again probably have to refer to these standard values. And this is the daughter of Van Herwaden himself. And obviously with this bit of coxa antitorta in the European nomenclature, which is femoral antiversion in the Anglo-American saying, well, that normalizes. And this is his daughter a couple of years later. So he doesn't see any issues with her. But obviously there are patients that have issues, as you can see here. And for those, you have to kind of go for further examinations. And this is what I've showed you before. You need to go into your rotation profile for these kinds of patients. So when you have then your rotation profile and you know where you want to fix it, then you can fix it and you need to equip yourself with some tools, obviously. So you need angles, you need a goniometer, you need some chisels, and so on and so on. And you need shunt screws and K-wires. So we have spoken about different levels of changing the rotational aspect. And there is rotational osteotomies at the proximal and distal part of both long bones at the lower limb. And this is the typical intertrochanteric osteotomy, which has been carried out years ago quite often. And we've kind of abandoned that for whatever reason, probably because of the fact that total hip arthroplasty was so extremely successful. So these were surgeries actually a couple of years ago or two decades ago that were massively used for cartilage issues of the hip as well. So and then there is these distal osteotomies, and that was the one that Al was going to talk about. So this is a technique from Jörg Hara actually, and I like the videos of him because they instruct that nicely. So this is the approach. And we've seen that approach from Al before, so this is why it fits to your case anyhow. So here you see the medial vastus. So in this case, it's a rotation from the medial side, but you can equally carry that out from the lateral side as well. So once you get to the vastus medialis and here the obliquus fibers, you can lift that up just like in the normal frontal plane corrections of the DFO. So that's what we do here. And then you need to get access to obviously the front and the back of the long bone. And here you see the three sisters that Al was talking about. Typically when you do frontal plane corrections, then this indicates the level of osteotomy. You can see those here. For the rotational osteotomies in general, we are a bit like half a centimeter or a centimeter higher because we want to rotate around this bromstick. So this is the LDF of the contralateral side for the medial side used here because it's actually more stable and a bit longer. And these purely rotational osteotomies tend to be a bit unstable. So this is why we seek for the highest stability that we can get. So the first thing he does here is actually he takes a look where the plate fits best. And there is a nice little trick from Mathieu who actually now applies the distal screws and actually creates the holes for those screws, and then takes the plate out and has half of the fixation already prepared. So you can do that if you want. What Jörg does here, he actually places the position and checks in the second plane, and then he fixes it temporarily with a K-wire to actually mark and maintain the plate position in height. And he does that in this oblong hole, in this, well, there goes one into this tiny hole, but there goes soon one into this oblong hole that you can see here, and the compression hole. And this is because when you place your K-wire there, then you can still shift the plate southwards. And this will be the K-wire later on that serves as a guide for the osteotomy. So this is exactly what we see here. And the osteotomy obviously needs to be parallel to the surface of the joint, so to the distal joint line of the femur. So it's not like in the standard DFO is a bit higher. It's obviously uniplanar. There is a technique described in Munich for a biplanar that I would not recommend, but we can discuss that later on. The non-biplanar technique reduces the overall surface of the osteotomy and therefore is inherently, obviously, more unstable. It's generally a bit under risk. For any femoral osteotomy, it counts that the lever arm that comes afterwards is longer than for tibial osteotomies, and therefore there is more strain on the osteotomy in general. So it's more difficult to get these to healing. So this is why a good plate and sufficient plate helps you here. So this one K-wire just stays in place. Then posterior to that, obviously, we need some protection. And what we then need is we need some torsion pointers. That can be done for the femur and for the tibia, or should be done, and it gives us some intraoperative control. And we use shunt screws for that because it needs to be stable, and more stable than K-wires because they bend, and therefore you have a loss of control then. So these work as pointers and not as joysticks. If you try to really rotate on these shunt screws, then you equally may loosen the grip and therefore have a bit of loss of correction of the angle that you applied prior to the osteotomy. And the angle that you apply actually needs to represent the angle of correction that you want to have. And later, after the osteotomy, you don't have to do anything else but aligning those shunt screws and fix the osteotomy. You need to make sure that they don't interfere with the position of the plate that you apply later on. And that looks like this. So approximately there goes one inside. Working equally here, there's a good trick as a retractor. So we go quite close to the anterior margin to lift up the vastus medialis. And then what you can do is you can line this up during the surgery, perform the cut. And once the osteotomy is carried out, you can just correct this so that you have it all aligned. So that is the rotational part of the osteotomy. In case, and that quite often happens, that all becomes a bit shaky, then intraoperatively you can just secure this. And this is why these shunt screws are actually great. So you can use an external fixator to just temporarily bridge this. And then you can safely put the plate on. And in case you have chosen a method where, like in Matt's case, you have already drilled your distal plate holes, then you can just find those holes back again, place the screws there and the plate is fixed. So the next thing you just need to do is to compress the plate here in these oblong holes in the shaft part. And then you just throw a couple of screws inside and that's it. And then you have compression there as you see in this anterior part. And if you like to, you can close the periosteum to seal up everything nicely. So this is then the distal femoral derotation osteotomy. So I've added this one again because we were talking about this. Now we go a bit southwards to the tibia, to the proximal tibia. And obviously these are the different heights and shapes of osteotomies you could perform around the area of the proximal tibia. So you can choose to go tuberosity or under, or you can do it in a biplanar way with an ascending or descending tuberosity cut, or you could just take the tibial tubercle off and fix it wherever you like. So obviously these ones just cover different ideas. Here you see the different heights of that. And it naturally follows the indication that the patient equips you with. This is a nice one as a rule of thumb. 20 degrees of internal rotation will lead to a medialization of seven millimeters. It's a nice publication once again, but as you've heard already before from me, I think this is strongly related to height of a patient. If you throw around with angles and metrics, then it doesn't work for everybody. It's just a rule of thumb. So you've seen that patient before. Obviously this is post-operatively, and now I show you what and how to do there. But I emphasized already that we need to focus on one particular structure if we carry out these cases at that height. And that is the superficial branch of the common peroneal nerve that actually underpasses the extensor longus digitorum. And that is what you see here. So this is the area where the extensor digitorum is. You obviously gain access to the tibia by peeling down with a corpse retractor. The tibialis anterior. And so far that seems to be easy. And then you perform the cut and rotate. And you just miss the fact that this little septum here compresses the superficial branch. So it's good practice to find that and incise it. And there is a brilliant video that I've never seen that spectacular before, but it's from Jörg Harrer from Bamberg, who worked with Strecker and now is in Lichtenfels, all in Southern Germany. So this is once again the area where you need to get to to do your osteotomy. So you peel back the tibialis anterior. And that is obviously clear so far. And now everybody obviously would have taken, and the same counts for me, would have taken some blunt retractor and try to place it in the back of the tibia to perform the osteotomy. So, but he's a bit smarter than me. So the idea is actually to find the nerve. So this is the main branch of it. And here you can see it coming up. In the very back of the extensor digitorum, you need to perform this little fascia incision. And here you find the superficial branch. And at this height, at this particular height, where this underpasses the extensor digitorum, what you do there is you just incise that fascia. And I'll follow this because it's actually a great video. It's very instructive. And if you want to have it, just come to me. I'll share it with you. I asked Jörg. So this is now what he does. And now you see this little, little flimsy thing here that you can grab. And that is your enemy. So if you rotate, this will have a chance. Not in every case, obviously, this happens, but this will have a chance to compress your superficial branch. And obviously, I mean, your patient will not be very happy with a drop foot after the surgery, so as you. So you better try to tackle this one. And once this is transected, you free the muscle, as you can see here. And once you have the muscle elevated, you can go ahead with the procedure, shoot your K wire, perform the osteotomy, and rotate. And the rotation obviously goes just like in the distal femoral aspect. So you have your pointers, and then you rotate. Once again, you make sure that these don't interfere with the plate position that you have later on, and then you'd simply plate it home. So the same is possible for the distal tibia, and we have spoken about that as well. So actually, it's two long bones with proximal and a distal derotation level. And well, the methodology or what kind of derotation osteotomy you choose, obviously, is depending on what the patient provides you with. Sometimes it is important in miserable alignment cases to do this at two levels, as you can see here. We've spoken about that. This is now a case that we don't have to run through. It's just to illustrate that sometimes you have to do it at two levels. And if you master each and every of those single derotational osteotomies at a single level, then obviously it's nothing else but putting frontal plane corrections together for a double level osteotomy. So Christian, I know that we don't like to have a specific number, but do you have a threshold number that you start to think about a derotation on the femur and the tibia? Yeah, well, it's actually everything which is under 20 degrees of rotation I would not address probably. But it's a highly individual question because cases differ. And for this lady with the inclining knee, with a click to the medial side, actually she had 45 on the affected side, whereas 25 is normal, or up to 25 is normal. So we've seen those values and you could refer to those. So it's actually exactly 20 degrees. And then what do you aim for? Well, I try to normalize it. I try to normalize it. But for those cases where you have one affected side and one non-affected side, the same counts like for tibial tubercle assessments that you actually check the contralateral side. And if she's having 30 there, then you would probably say a rotation, derotation of 10 degrees should be enough. If you just normalize what the other side deals with and doesn't have any issues, no clinical findings. How often do you find a high femoral anaversion without, with normal tibia? Well, that actually works either way around, but I know what you wanna talk about. It's actually the typical situation where you have these miserable malalignments often in female patients as you raised already, 30 years of age. And it's very common there that both go together. But if you, when you derotate the femur, you have to externally rotate it. So you could take a normal or semi-normal tibia, but you're actually pointing the foot more external then. And so it's often hard that to do both when you start with the femur. Yeah. And particularly when you know that obviously external rotation of the tibia is known. It's not external rotation because when you just rotate the femur, then you don't rotate naturally the tibia. So the tibia remains at that position. The only thing that you create is an outwardly pointing foot. So, but foot progression to the lateral side, to the outer is actually quite well accepted, whereas inwardly pointing feet are not accepted. So it's a gate disturbance. So you have to ask yourself, is it reasonable to do that, to correct at both levels? And do you need that for your clinical success? And in case of doubt, it's never wrong, I guess, to do that staged. Yeah. So let me just finish off with this one because I'm done then. And take-home messages is check for rotational deformities. Obviously, we have learned that the Staheli profile is important, but equally CT and MRI scans are important. And also the clinical assessment and check the gate abnormalities. Analyze the deformity thoughtfully, as we were mentioning all the time. This is a very, very tricky plane to analyze, and therefore it remains difficult. In fact, Ronald van Herwaden always says, this is expert surgery. Please refer those patients to me. That's a quote, it's not my statement. And sometimes it goes together. And obviously the patellofemoral aspect is always some part of this enigma. And that's a problem because it's multifactorial. And then it becomes even worse because then you don't know, is it purely bony? Is it soft tissue? What plays into the pathology of my patient here? But there is no way around, you just have to analyze. And that was it, thank you. Can I make one comment? That was an excellent talk. Not every patellofemoral patient needs a TTO. That's the point. And recognize there's compensated and uncompensated femoral anaversion. And that's what Elizabeth was trying to talk about, right? If your foot progression angle is internal, your tibia is okay. Just focus on the femur is a home run. But if your foot progression is normal, your body compensated, and then those are the ones you have to consider double level osteotomy. My question to you, Christian, is that we're pretty good, and realize I am a hip and knee surgeon. So I know version very well. We're pretty good at assessing femoral version from a CAT scan basis. We look at all different levels, as you showed very well. The data is pretty good on that, meaning that it's off, not perfect. Tibial torsion, the data is not nearly as good. What's normal tibial torsion? And how do I correct it? So? Stop the mic. Go ahead. Go ahead. I have a very good story, because it's HSS based. When I was a traveling fellow in ESCA, you remember that. So I'm starting to have a lot of PSI from Nuclip, and I asked them to give me the torsional aspect, the value of the torsional aspect. And I look at, and I received tons of them with like 35, 40 degree external torsion of the tibia. And I was like, I asked Roman, I said, what is the normal value of the tibial torsion? And Roman said, I think it's about 20, 25. But I don't know. And we look at the literature, there was almost nothing. So he called Bob Taichi and said, Robert, give me the normal value of torsion. And Robert sent him eight pages of literature review without any real answer. So at this time, I was working off of Striker, Soma database, we have 2000 CT scan inside. And I asked them, measure me the torsion for every 2000 CT scan. And the answer is very clear, it's 31 degree plus or minus six, any ethnicity, any gender, 31 plus or minus six. So it's a very narrow window. So in between, let's say 25 and 35, it's a normal value. So you have a quite clear answer here. 31.2. And I may add, probably the reason for that is that it's just clinical. It doesn't have these implications. Because as we mentioned, the direction of the foot follows a higher variability as the orientation of the knee joint. And that is obviously the next joint that comes after. After femoral rotation, you have the knee coming. And after tibial rotation, you have the foot coming. And there is obviously, as this is still compensatable in the foot itself, probably is not that important. I wanted to make one point about anterior knee pain. Because we have the privilege of having a good gait lab in our city, which is done at the Gillette, the children's hospital. And sometimes, I believe that they have some version, usually external tibial torsion, but maybe not enough to correct. But here's usually a teenage girl, usually a teenager, usually girl, female. And I sent him for a gait analysis, not so much because I think it needs to be correction. But you need to validate that person's pain. And this is a typical person that is OK in ADLs, OK in everyday activities. They just can't. They have pain when they run, especially if they excessively run, especially if you're in soccer or some kind of excessive running sport. So I've had several cases where you have the slightly high torsion, whatever you want to say it is. Then you say what you might need to correct it. Then oftentimes, we say you might not make a comfortable runner afterwards. And they're fine. They're fine to give up that activity. So I think that sometimes, finding just small degrees of torsion and explaining that this may be a variation of why you have pain when you're more active is enough to validate their pain and not send them to the psychiatrist. So not always do I look for this to be to do surgery. Sometimes, it's just to, again, validate this pain in this teenage person and say, you may not be appropriate for everything. You may not do all the activities. Yes, Liz? You mean whether you're doing femur tibia or whether you're doing a proximal on the femur tibia? I don't know that answer because I do it mostly one way Me neither and I cannot Retrospectively say on the individual patient if the other one would have worked But actually when we referred to Matt who changed his practice I would rather say you have the biggest cohort of patients having done both levels. So and and what have you seen? It seems to work for you distal and proximal the question was distal and proximal rot derotation osteotomies Of the picture from such a man. Yeah So so what do you what what is your what is your take on that? My question is what is the party tonight? Yeah, anyway, so do it again, please. So the take on you have the most insight into proximal derotation and distal derotation tibial osteotomies So the question was is there a Difference in gait when you analyze your gait whether you do it and the proximal or distal side Nope, I don't know. Okay No, would you not agree though? If you go proximal that it on table your patella tracking seems to be better on table with a proximal osteotomy Maybe because you you change a TTGT then but apparently that doesn't matter and maybe you don't do it depending on the choice of your Osteotomy, so okay. I think we can continue this on all night, which we're obviously not going to do So I'd just like to give a round of applause to all the speakers and all of you today for it's been a long day And I'll say again. Thank you very much to everyone for in the lab as well Huge help for all of us going through all the technical aspects. We are gonna have a 15 minute break We're gonna there's beer and pizza outside. Hopefully grab a drink We're then gonna have a bit of a confession session because we've we present a lot of complex surgery today But unfortunately, we do have complications and I think it's important that we learn from those as well so it should be a bit of a fun session, but it's a hard stop at 830 and We'll see you back in here shortly

chronic patellofemoral pain

rotational issues

alignment problems

rotation problems

45-degree external rotation

osteotomy

internal rotation

deformity correction

fixation with screws

pain improvement

functional stability

diagnosing rotational deformities

femoral external rotation osteotomy

tibial internal rotation osteotomy

shunt screws