I'm going to talk a little bit about atrocoloplasty. This is a little bit of a different talk. I want to talk a little bit about perspectives across time and borders. A little bit of the United States' history, which is a little bit of my history from Minneapolis largely to Central Europe and Lyon in particular. I want to just talk a little bit about my trochleoplasty journey. As many of you probably know, the first trochleoplasty was actually by a general surgeon in the United States, Fred Albert, who did the Albee procedure in 1915. This was in our literature, in our instruction books in the United States. Campbell's Operative Orthopedics in 1935 listed this. It had many concerns and issues. It was not largely embraced. And by 1980, it was gone from our orthopedic books. And was not included. Talking about trochleodysplasia, we really didn't see this term too much in the American United States literature. Dr. Merchant used the term patellofemoral dysplasia in the late 80s in describing different patellofemoral pathologies. But we did have something that happened, and we began to take axial views. Now the first axial view was actually by a German in 1921, but it came into our existence mainly through Jack Houston in the mid-'60s. And he did it in a prone position, in a deeper degree of flexion. But it did give us an opportunity to see the position of the patella in the groove in early flexion in a common clinical setting. For patellofemoral pathology, we believe low flexion is more important. And the two more common ones are Lawrence, who is a Canadian, and Merchant, of course, from the United States. And these are the two most popular ones used for looking at the pathology of the patella in early flexion. But what happened is that we became very focused on patella position. And in fact, that term patella malalignment came into existence in the United States. And there's many examples I can give you. But I will just point out that in 1971, John Insel felt that patella malalignment was the major cause for anterior knee pain in young people. And there was a lovely article by John Fulkerson and his good pal, Dr. Dupont from France, that did talk about the trochlea and trochlea dysplasia and the patella position. But he felt that that was more confirming patellofemoral malalignment. And it was difficult to know exactly what we meant by this term. And so we did have ways that we could look at the patella position through slice imaging and then have surgeries to correct the patella position in the groove. Now meanwhile, in Europe mainly, other places as well, but they began to look more at the trochlea. And they described trochlea dysplasia as looking at the true lateral X-ray. And when you had the crossing sign, which is the evidence that the groove is more anterior, this was the example of how you describe trochlea dysplasia. And as you might know, that became part of the four patella instability factors that were laid down for the Manuela CART for patella instability surgery done by Henri Desjardins and John Walsh, which was introduced in our English literature in 1994. And so I think that what was happening in Europe and other places is that they were concentrating more on the trochlea. And in the United States, we are concentrating more on patella position. I do think that we've had many contributions in the United States. The clinical utility of the axial view, how we used it, of course, is important. The soft tissue envelope of patellofemoral function. Thank you, Scott Dye. And of course, MPFL anatomy and surgical reconstructions. Of course, we weren't the only ones doing it. But I do think that as a group, we did contribute this to the patellofemoral literature. But I do believe that this patellofemoral in general is poorly taught in our orthopedic educations in residency. And thankfully, courses like this improve the CME. And John's course helps to improve that global education. I do believe that there's still concern for cartilage health, despite the American appetite for cartilage procedures in other places of the knee and other joints. And I do think that the surgical treatment of trochleoplasty continues to be a rare event. So what's changed? I really do think that there's been an explosion of knowledge, largely based by our international connections and our ability to do things electronically. Although these aren't the only sites, there have been many great sites internationally that have added to international knowledge of the patellofemoral joint. I also have to credit the International Patellofemoral Study Group, the IPSG, for helping to meet John and to promote this international collaboration. I do think that as John has tried to state, that the spectrum of trochleodysplasia is quite broad. And the one that we're really concentrating is the one with the big supratrochlear spur. What we're really looking at is that convex trochlea. And we have come to recognize this. We can call it a supratrochlear spur. I'm not sure that's the best language to use in English. It could be a ventral prominence. You could call it a boss. But we can measure this. And typically, greater than 7 might be an indication that you could be reducing that because it's quite a big prominence for the patella to glide over. And we do know that this dysplasia is primarily in the central part of the groove. Now what has changed me? Why did I change? Well, two things. One is this, jumping J sign. Although you can have some surgeries that will improve it, it's really very difficult to make better without doing something to the bone. And primarily, that's doing something to the trochlea. And this combined with seeing all of the cartilage restoration that was being done in my center by my other sports surgeons made me say, I want to try this trochleodysplasia and trochleoplasty correction. So for me, at least to start, I wanted to see this jumping J sign in the patient. You needed a ventral prominence greater than 7mm. And you needed that convex trochlea. I'm going to say no significant patella alta because there still is the thought that if the groove is normal below and somewhat deep in mid-arc flexion that we can bypass the bump by doing a TTO distalization. I will say that that does help. It's not always helpful. And I think we still have to do more analysis on the trochlea as to when a distal TTO might help. I think that the main goal of this is to flatten the convexity and try to improve the groove. But it is difficult to take it to a complete change in that groove anatomy. You can use a flexible flap if you're able to get it that thin. And you can use one with an osteotome. And I believe that when you use it with an osteotome, you have a better chance of recreating a groove. I think that the concern for cartilage is less important. I think we've got plenty of good studies. These are my own views of second-look arthroscopies. And I've seen certainly not in my early period of trochleoplasty any harm to the trochlea. And I did my first trochleoplasty in 2007. And I do now have almost a 15-year experience. So in conclusion, I do think that trochleoplasty is a valid option. And for me, I look for high-grade trochlea dysplasia with a supratrochlear spur or ventral prominence with satisfactory cartilage surfaces. A J sign is helpful, particularly in my early experience. These are the patients that I mostly gravitated to. And I do find that they have significant improvement primarily in quality of life and sports. I do believe that it's important and it's a necessary tool for people who do a lot of patellofemoral surgery. And although cartilage health has been a concern, I think that more literature is supporting that it's related to the trochlea dysplasia rather than the surgical intervention. And although this is clearly Level 5 evidence, John's already shown that we can lead to cartilage wear both on the patella and the trochlea. And I would say to do nothing might also not be the way to preserve cartilage health. Thank you for your attention. And again, I want to emphasize Issicus in Munich in 2025.

trochleoplasty

patellofemoral surgery

trochleodysplasia

international collaboration

cartilage health