Reducing osteotomy, yes, we will speak about osteotomy, but also about ACL, and the bony morphology is definitely very, very important in ACL deficient knee, and I would say it's mostly fundamental. So when you speak about ACL, you speak about AP, arterial-articular translation. We also speak about an excessive internal rotation, and when you walk, when you go on the stance phase, you will put some strain on your ACL, and you will increase the strain on your ACL. So this is probably one of the biggest primary interesting factors for an ACL tear is a slope, the posterior tibial slope, and this is correlated to the static anterior tibial translation, and this is very important to link the two of them because more you have an increased slope, more the strain on your ACL is high, and more you will overload your ACL or overload your ACL graft. So when we speak about the static anterior tibial translation seen on the monopedal wake-bearing X-rays on the lateral view, it is directly correlated to the slope, it is correlated to an increased graft stress and increased to the graft failure, definitely, and this is something very important, and we are looking at that because when you walk, you will increase your strain on your ACL. And definitely, when you have done just your ACL and your graft is a little bit weak, if you have a high static anterior tibial translation before surgery, you will increase the strain on your graft, and maybe this will lead to a graft failure by fatigue. So this is important. We know that there is a threshold, 12 degrees, using the proximal tibia method to measure the tibial slope. It is very important to be specific on the method that you are using, but for sure, you have to look at the meniscus also because there will be a soft tissue tibial slope also, which is correlated to the increase of the static anterior tibial translation. So there are many, many articles now about the relationship between the slope and the ACL rupture, the pivot shift, and we have shown also that when you are doing an ACL graft alone, it will not correct your static anterior tibial translation. The graft is not strong enough to correct it. So speaking about the osteotomy and deflection osteotomy, we have to acknowledge the fact that in 1992, the vet world discovered this surgery and used it for ACL rupture. This is the surgery for an ACL rupture in dogs. So the sequences are, first you do, we're talking about revision this year, first you do your tunnel placement, your meniscus management, then you do your tibial deflection osteotomy, and then you pass your graft and you fix your graft. These are the sequences, one-stage surgery, of course. And this is the video that you will learn about how to do this classic deflection osteotomy. You do a skin incision according to the graft that you will harvest. So of course, you have to go about four centimeters below the dog line, and you will have to expose the proximal tibia. The first is very important to mark the patella tendon insertion, as we will not do a TT osteotomy for this surgery. It is definitely not necessary. You will see that later. Then you release the MCL and the fascia latae and the tibialis anterior. And you know then, when you are doing some total knee arthroplasty, that you can release all the deep MCL all around, you will never get any laxity. So it's very important to be confident. It's very important to show perfectly the upper part of your tibia. And then you will have the two retractors. You have a very nice exposure on your proximal tibia. Here again, the patella tendon insertion is very important. This is a landmark for your first key wire. And this key wire reaches the posterior part of your tibia, one centimeter below the joint line. You put the second one just parallel to the first one and parallel to the joint line. And then you will mark your osteotomy. We consider that it's a one millimeter for one degree, and we just published the fact that the target is four to six degrees for the final tibial slope, if you want to correct the static anterior tibial translation. So you put your two key wires and then you will follow your key wires with your sole. Of course, you have to be careful of the posterior part of your tibia. You just knock on the door and when you do that, you will never be in trouble. And it's very easy somewhere, but you have to go slowly and knock on the door. This is the key that I can give you. So you go first under the key wire just to prevent going in the joint. So it's good. You do that the same for the second cut. And while you are doing that, you will see progressively that your wedges are moving. It means that you did a very nice cut and you see the wedges just start to move. You do a biplanar osteotomy because you have to go just behind your peterotendon insertion. And then you test your hinge and you see the hinge is moving. Perfect. Nice. Very nice. And then you remove your wedges with some tools, with some rounder. And as Al Gertrude said, sometimes you can drill your hinge posteriorly so you will weaken a little bit your hinge and you will close it maybe more easily. Then you push down and you see that your osteotomy is closing nicely. We put a staple, a temporary fixation with one staple on the lateral side. So very light fixation. You check with a fluoroscopy. You measure the slope on the fluoroscope and if it's okay, you put the second staple on the medial side. Of course, you have to be careful of the tibial tunnel that you have done. The target slope is four to six degrees. You redrill your tibial tunnel and then you will be able to pass your graft from, we do outside in. So this is the way we do and we fix that with two screws. We fix the graft at 70 degrees flexion. So we overtighten the graft to prevent the hyperextension. And we will use definitely a brace post-op. We close the medial and the lateral side of the knee and the surgery is done. It's really beautiful as we can see. So the technique, we just published this article to show you that it's absolutely not necessary to do a TT osteotomy when you do this tibial slope correction. You have enough bone above the tibial tubercle. The consequences on our series, we have shown that we increase a little bit the MPTA. So be careful. One degree is almost nothing, but it's something. And we increase a little bit the patellar height. So when you do this surgery, be careful to not to be more than that. The slope target, if we relate the tibial slope and the static anterior tibial translation and this is very important to relate both of them. And the 12 degrees threshold is an expert opinion in fact and it's not really true. You have to look at the static anterior tibial translation and you will correct 0.46 mm for each degrees of decrease slope. So the target is definitely 4 to 6 if you want to be good. The results, we have two series, 7 to 15 years follow-up, which is quite a lot. No re-rupture, no new surgeries, no meniscus injuries. Very short series of course, but people were really happy and we feel that you stop the natural history of your ACL when you do that. Arthritis, not so much. We have increase on two, but the follow-up is 15 years, so it's almost normal. We published, and it was in the second ACL revision. We published just this article in CASTA recently for the first ACL revision because we are so confident with this surgery. But definitely we push a little bit the indication for the tibial slope osteotomy. And here again, at 7 years follow-up, no re-ruption, one meniscus surgery, no arthritis. Very good and we are very happy. So what about the primary tibial slope deflection osteotomy in primary ACL? If you have this guy, 15 years old, 30 degrees tibial slope, static anterior tibial translation, 9 millimeter root tear. If you do only an ACL and you see him two years later with a new ACL rupture, you will be very upset. So maybe sometimes you can do that primary. So what to do so? Look at your patient, look about the ACL, but also about the environment of your ACL. It's very important. Take your ruler, measure, and osteotomies is definitely one of the tools that you can use to treat a failed ACL. And if you want to avoid an ACL failure, don't miss your target. You have the AP translation, which is corrected by the tibial deflection osteotomy, and an excessive pivotive, which is correct by an extra-articuloplasty. So the goals are different, and don't miss that. This is my conclusion. It's probably the best way to stop the natural history of an ACL tear. Thank you so much. Well, really, really, really nice. And I've heard your talk over the years, and I can see at the end, all the questions I'm going to ask you, you've started adding slides to it. I still want to get back to some of those, and please, if you have questions, you know, David makes this look so easy, and then you go home, you know, I said this yesterday in a course, but you know the worst day for a patient to come to your office is when you just came back from a conference, right? So this is a quote from Werner Müller. So be careful, you know, you see these things, like, I can do this, you know, and this is basically in real time, what David showed, there wasn't any speeding up. So you understood that it's good to do this to me, above the TBR they did, because yesterday I heard something wrong. Well, I can tell you, this is just my personal experience, you know, I did come home one day from a meeting and started doing this procedure, and it took me a solid two hours. And of course, in the end, everything went well, but for a while, I did elevate the tubicle, and then after 20 cases or so, I get more comfortable, and so I went back above the tubicle. But it's just something you need to figure out for yourself how to do this. I recommend highly to you that you go to this course in October and many other courses, or that you have maybe your own lab where you go and try this. You do not try this procedure for a first time on a patient if you have never done it. I will add something. It's a difficult surgery, it's a tricky surgery, as we say, but the key is the exposure of your TBR. And if you are confident to release your deep MCL, to release your fascia lata and your tibialis anterior, it's easy, it becomes easy. So this is why it's good to know how to do sports medicine and also degenerative knees, you are used to release MCL when you do a total knee orthoplasty. So like you have shown, you overcorrect, so if the native slope, you know, on average in a human should be around 7 degrees, when you do a slope reducing osteotomy, your goal is to go to what? The target is, we have no target at the beginning, and we said 12 degrees, we correct the 12 degrees, and my goal was to overcorrect a little bit. And if we are looking back to the different series that we have done, I have seen that sometimes my slope was close to zero or two, and I have a posterior tibial translation, which is okay, but somewhere not really beautiful. So that's why we worked on the last work that we have done, we correlated the static anterior tibial translation and the slope to get the final target. And if you want to have, to reduce your static anterior tibial translation less than 5 mm, the target would be 4 to 6 degrees of tibial slope. Yeah, very, very good. And so when you do a second revision ACL, is there in your practice a scenario where you don't do the slope osteotomy, you just do a third, you know, ACL? Yeah, yeah, sure. Which is that scenario? The scenario is, I use, you have seen that we use a lot of the x-rays, and my, what is most important for me is how much you have translation on the weight bearing 20 degrees flexion x-ray, sagittal view. If you have less than 5, it's not necessary to do anything, because you will not over-constrain your ACL graft. If you are more than 5, you will increase the strain on your ACL graft, you will get a re-rupture. So this is my indication. So my indication is not now only the 12 degrees tibial slope, it's the two things. What do you think is worse? What is? What is more important to you? Static anterior tibial translation. So even if you had a slope of 10 degrees, you had 9 to 10 mm? I do it. You do it? I do it, yes. How often would you expect a slope of 15 in a revision ACL with not having anterior translation? Is it possible? I don't know if it's possible, but it should be rare. As long as it's due to meniscus status as well. Of course. That's very important. The meniscus status is really important, definitely. I would say MRI, the soft tissue tibial slope is not so reliable, but it's clever to think about. We know that if we change slope, we can dampen anterior translation, ATT, and we can make our ACL more stable. Yeah. We also know that some of our outcomes from PROMS is not great. Do you think that we're changing the load on the knee, and that may actually be, although good for the ACL, bad for the chondrostatus? I would say it would be good for the cartilage because you change the contact point and you move it forward anteriorly, and when you have an ACL, the contact point is posterior. Yeah. I mean, we did this in the laboratory with Philip Winkler, and you really unload that meniscus. The meniscus, when the tibia is so anterior, is just squeezed. Yeah. Go ahead. Your static view that you take in measurement, you say it's 20 degrees of flexion? Yes. That's how you shoot that? Yeah. It's like this tense phase, in fact. We do that under fluoroscopy, like that. One last question. You showed one slide for three seconds talking about a primary ACL. I want to hear more. What scenarios or how many? Tell me more about a primary ACL. Would you go there at what degree of slope and what amount? You showed us this one kit that had already in a primary ACL that much anterior translation. That's rare, I think, but if you don't look for that, obviously you won't see it. It may see you. When do you do this? I do some. I do very few of them. This is maybe my next step. I went from the second ACL revision to the first and maybe to the primary. Each time, I do quite a lot of young patients. Each time, I do a patient of 15 years old or under 18 with a tibial slope of 13 or 14. If I do my classic ACL plus an extarticuloplasty, because it would be systematic, but I know that if I will see him again in two years with a re-rupture, I will say, I was so stupid not to have done that. Yes. Really. In all of your patients that come in with the story of the knee had a pop and, you know, there's going to be an ACL, all the patients get a 20-degree flexion weight-bearing x-ray? Lateral? Yes, we do that in my hospital. Yes. This is mandatory. Do you have that? We do that with the telos. Very good. Thank you. Any other questions? Thank you, thank you.

bony morphology

ACL deficient knees

posterior tibia slope

tibial deflection osteotomy

ACL re-rupture