So, well, in fact, it was not simple to complex, it's only complex on this morning. We have seen a lot of very complex cases. So this is a woman of 24 years old, left knee dislocation, both knees since 10 years. She has a high apprehension. She is not doing any sports activities and she would like to play basketball. And she had some family antecedents, and it's a question that you should ask every time. On the clinical exam, both knees, a little bit of valgus, three degrees, range of motion, hyperextension, 10 degrees of recovitum, very painful and she has a great apprehension. What is patellar-specific is apprehension, yes, the tilt, you test the tilt with your hand and you will be able to know if you are able to reduce or not the patellar tilt, and this is something important in the decision of doing a lateral release or not. The quadrant test is four on four, and there is abnormal patellar tracking, like a jumping J sign. I call that abnormal patellar tracking. This is it. And you see, when you flex the knee, the patella relocates. So it's a relocation in, reduction in flexion, which is different from your case that you have seen before. The abnormal tracking is always a sign for me for high-grade trochlear dysplasia. So this is what we should start always with imaging, AP, sagittal and axial, and what we can look at that. On the AP, definitely there is a rotation problem. On the sagittal, we will measure the height of the patella, and there is a little bit of patella alta, 1.2, and the trochlear dysplasia is a trochlear dysplasia type D, because you have all the three pillars with the supratrochlear spur, and you have seen this morning how important is this bump, and look at this bump, because this is the key for picking up the high-grade trochlear dysplasia. You have the double contour, and you measure the bump on the x-rays, but also you can measure that on the MRI. And it's very important to quantify it, because this is one of the big, big, big risk factors that you need to correct if you don't want to face a failure. X-rays, you have the flat trochlear, you have a flat patella, Weiberg number three, and you will find again that on the slides imaging with lateral trochlear inclination, six degrees, the tilt of the patella, and this is the same patient, x-rays and MRI, so you see the patella is tilting all the time because the patella is on this lateral convexity of the lateral facet. So definitely x-rays and MRI doesn't give you the same information, and you need to use both, and this is one of the messages that we should remember. Then we do some measurement, always do measurement, even if your PAX is not able to make it, try to make it, export your DICOM images to a software which will allow you to do measurements, so important. So you quantify the TTTG, you quantify the rotation, and then you will be able to know exactly what to do. You list all the risk factors, trochlear dysplasia, patella height, the excessive TTTG, the tilt, and you list the secondary risk factors, femoral interversion on this patient, the valgus, and then you make your decision, and you do le menu à la carte as you know. So this is, we have time for an open discussion about that, or I go ahead? So what I did, when you are in, this was the patient, and this was the trochlear dysplasia, and you see, when I removed the bump, this is the preeminence, and this is what you need to correct by doing a trochlear blasting, and if you are not able to correct that, every time you want to correct that, you will have to over-correct, over-tight your MPFL, over-correct your TTO, well, you will not correct where you have to correct. So this is exactly what you have when you do total knee arthroplasty, you will never accept that when you do a total knee arthroplasty. So what I have done, I did a trochlear blasty, the goal is to make the trochlear flush with the anterior cortex, not to deepen it too much, the goal is really to be flush and to decrease this pressure, it's like an anti-Mackay effect, so you can do an anti-Mackay effect on the trochlea, or you can do an AMZ, whatever, but you are able to make your choice. You realign the trochlea to the anatomical axis, exactly, this is one of the goals of the trochleoplasty also, it's to do a proximal realignment. This is the post-op, I did the deepening trochleoplasty with a 4mm proximal realignment, I did a TTO osteotomy medialization 10mm, a mild destabilization because of the patella alta, and of course an MPFL reconstruction, which is mandatory. This is a 2 month post-op, you see that the trochlea is flush with the anterior cortex, the TTO healed, the MPFL has a pretty good position, and the sulcus angle is back to almost normal, and this is the x-ray 2 years later, and you see that the anatomical result is really good, CT scan control 2 years later, the TTTG is corrected, 15mm, no more patella tilt, and that's it, thank you. So there is some discussions. Yeah, and I know time is short, but you have more experience and wisdom when it comes to trochlear dysplasia than anybody in the room, so many people here aren't doing trochleoplasty yet, but they want to know when should I find a person to do it, or when should I maybe take that plunge. So what about a patient, most makes you think that I probably need to do a trochleoplasty, is it the shape, is it a combination of risk factors, is it how large the spur is, is it a convex shape, what is it that you kind of look at and you say, I really need to change that? Two things. The first is the abnormal tracking, inflection or inextension, this is clinical, and then you move to imaging, and you have to look at the bump, the proeminence of your trochlea. This is the key. Every time you have a proeminence more than five millimeters, you have to correct it, because this is the reason for the paternal instability. What if it's prominent but flat, would you still correct it, would you feel strongly about that? Yes, yes. The proeminence is the key indication for the trochlear, for the trochleoplasty. I'm not pushing for trochleoplasty all the time, and they ask me how many trochleoplasties I'm doing per year. I'm doing 30 to 35, so it's a low number, and I have a very specific recruitment. But each time you have this bump, do something. You have seen this morning all the cases, and also something abnormal on the trochlear side, and this is what you need to correct, and it's not so tough to do it. Yes? I agree about that, and sometimes you can do an engagement trochleoplasty. It has been described, and it might work, especially if you have a little bit of arthritis, but as I've seen on your case, probably you can make an engagement trochleoplasty, I call that. I'd like for you to tell us the percentage of TTOs that you had in combination with your In those patients which are really high-grade patella instability and when every time you have such high-grade trochlear dysplasia, I, most of the time, I do medialization of the tibial tuberosity, destabilization or not, but I feel that the proximal realignment that we are doing in the trochleoplasty, most of the time, is not enough and you have to do something on the tibial side. I think that's a fantastic point and I agree and the longer I do this, the more important I think that is. You've got to somehow address the vector. If the vector is still pulling it sideways, you're going to potentially have problems. You can't fix it all with the trochleoplasty. So increasingly, you're doing something to correct realignment as well. So that's great. The other thing I would just share is I look also as just a shape and if it's a large bump but it's convex, I think that's pretty important. That's going to create that problem with the patella just wobbling. to visibility and that rotation is highly associated with appropriate displacement. So the question is, is that moving rotation being dynamic? Good discussion. I think any other points? If not, I know we've already run over. I just really want to thank the faculty. I think it was a great discussion of the tables and thanks to everybody for coming. You guys enjoy the meeting.

knee dislocation

trochlear dysplasia

patellar tracking

trochleoplasty

MPFL reconstruction