I'm Jackie Breede from Portland, Oregon, at OHSU. And I'm going to just start with a case. Here, I'll take this thing off to present. So SW is 15, and we're dealing with her right knee. Her first episode of instability was when she was 13. She dislocated when she got clobbered playing softball catcher. She had five subsequent events, most recent two months before her presentation. She'd done a year of PT. A lot of these patients will come just sort of demoralized about PT and prospects there. She had a steroid injection, didn't seem to improve her symptoms or her instability. On exam, she had neutral clinical alignment. I did a rotational hip exam that was unconcerning. Her Baton score was high, so 7 out of 9, pretty stretchy. And her range of motion was good, so she's out from under the acute inflammatory phase of her injury. She had no lag on straight leg raise, her quad is firing, no J sign, no crepitus. Very apprehensive, though. I can't tell you her patellar translation on exam because she wouldn't let me do a lateral translation. So here are her x-rays. You can see those closing physes in this 15-year-old. I measured her Catan de Champ at 1.12 and her du jour A trochlear morphology, so mild dysplasia, no super trochlear spur, no double contour. This is her merchant view, so no excessive lateral tracking there. And on MRI, she had a lateral trochlear contusion consistent with a relatively recent instability episode. Her proximal trochlea looked nice in terms of having an actual groove. A little bit shallow, but no major convexity. And if you look at the patellar tendon tracking relative to the condyles, it's nicely centered as well. On sagittal alignment, you can see the patella on the slice with the ACL and the views. That's always a good sign in terms of lateral tracking or lack thereof. And then, oh, I should also mention good articular overlap between the patella and trochlea there. You can also see that closing tibial physis on its way distal femoral physis. And I measured her TTTG at less than 5 millimeters, so definitely not in the range of the abnormal 15 to 20. So options here, and Dave, do you want me to stop and have them discuss? I think this is good. So let's just discuss at the tables. I've got some options, including lateral release or lengthening. Medial retinacular imbrication has been popular in past years. VMO advancement has gotten some lip service in distant years. And then MPFL repair versus reconstruction, would anybody add tibial tubercle osteotomy? All right, sounds like some great discussion happening in the room here. But for the sake of time, let's bring it back and we'll finish out this case. Did anybody's table vote for isolated lateral release in this ligamentously lax teenager? Got no takers. Did anybody vote for MPFL reconstruction? Most folks in the room? OK, anybody vote for anything else want to shout it out? Anybody are going to repair this thing? Yeah. On the x-ray? Here. Yes. OK. Yeah, so on the standing AP, a lot of these patients actually, well, two things. One, the patella looks like it's actually sitting a little bit medial. It might be that the limb is slightly internally rotated. But very frequently, these patients, the patella will be resting laterally. The second is, it looks like there's an exaggerated flare on the lateral distal femur, that metadiaphysial flare, and that the medial side's straighter. So even though there's not, by report, there's normal axial rotation. I guess for some of these where maybe something seems a little bit off, I would have a lower threshold to do a CT rotational study. So I really wondered why this patient dislocated. Yeah. Do you have any thoughts about that? Yeah, great points, great thoughts. And especially if there was a J sign, I think the J sign's been shown to be associated with rotational abnormality. And so you really want to have a low threshold, especially in youngsters who dislocated early. It does make you wonder. I think maybe her laxity is her one major factor. Her one major factor, and she had enough of a traumatic injury to disrupt those soft tissues and really tip her over the edge. Because she really is remarkably sort of normal anatomically for a patellofemoral dislocator. So yeah, we proceeded with MPFL reconstruction. Here you see the classic location of Schottel's point. And I wanted to talk a little bit about how to pick your fixation points. This lateral x-ray is a patient of mine. Real signs of struggle there on the images of the previous attempts at MPFL reconstruction. So on the patellar side, you've got options ranging from proximal patella to distal quad tendon, and even quadriceps autograft itself. As the sort of periphery of the circle, the patellar fixation, or the extensor mechanism fixation is a little more forgiving in terms of location. Adam had some really good data on exactly what you're stabilizing and in what range of motion. So in that early range of motion, you might not have as powerful a stabilization if you're picking the MQTFL. But if you have a patient like this, who's had many, many holes in her patella, you don't want to add more, that's a good option for you. So here's Dr. Fulkerson's MQTFL. He weaves that into the distal quadriceps tendon. And if you look at where that is relative to the superior pole of patella, that does have a downward curve. And so you do end up sort of parallel with patellar bone there to some degree. So you want to suture that into place. And then here's Christian Fink's quadriceps autograft option, where you can turn down the quad and suture that in place as well. On the femoral side, the fulcrum of this circle is much more important in terms of room for error. So the common mistakes are too anterior and too proximal. And if you look at the most egregious of these attempts here, the MQTFL is going to be much shorter in extension and stretch or fail with flexion or cause pain with flexion, right? And so you want to use your X-ray to locate this thing, but check your isometry. So I've got an example of this here. I've got the middle of a hamstring graft secured to the patella with two anchors. And I've got the two limbs wrapped around a pin. That's my shuttle's point on X-ray. I don't use a tourniquet, apologies for the lack of clean field here. I'd kind of made the AV guys nauseous last time I uploaded this thing. But you get the idea that I've got a clamp on those two free ends. I've got it wrapped around the pin and I've arbitrarily marked across those limbs, right? So you've got this sort of level start point and then you're taking the knee through a range of motion. And if those marks move, then that means it's an isometric. And if they stay parallel to each other, which you can see in this image, they're staying pretty parallel. Nothing's really moving. That's a nice isometric graft. So I'm going from zero to 90 and I like that isometry. I'm going to buy that position for my femoral fixation. If you want to fix to the femur first, then you've bought your isometry, right? This is the fulcrum. Then you've bought it. You want to identify any anisometry in the system. So you do the same thing. You do a provisional fixation to the patella and then you see at what degree of flexion of the knee is your graft tightest. So that if you fix it at that degree of flexion, it will only loosen. This is Dr. Fulkerson's preferred technique. So there are options here. And so once you've picked your spot, you're going to set your length. Patella femoral surgeons hate the word tension when it comes to MPFL because it's supposed to have minimal tension. So you see us dunking this thing. This is a pull through technique, pulling those sutures tight. Now we're too tight. We're going to let go. And I'm going to take this knee through a full range of motion to let this graft set its own length. And then I'm bringing it to full extension and checking my patellar translation to make sure that I haven't over-tensioned that graft. So we'll fix it in flexion here. The MPFL reconstruction can be safe in the growing patient. So the physis is undulating and the central undulation decreases in size as patients age. I think you'll hear a little bit more about this from Lee Pace, so I'll be brief here. But there is a safe zone to get distal to the physis. The MPFL should originate from the femur distal to the physis. So you can either angle your socket or you can do a pull through safely. So if you look at that Blumenstats line on the lateral there, there is a bridge of bone that you can follow across. And then if you want to spare the physis without a femoral socket, there are many options that are found. The MCL sling, you can wrap a graft around the MCL. You can wrap it around the adductor magnus. You can harvest adductor magnus itself as your graft. You could use a suture anchor instead of a socket or tunnel in the femur. You just want to think about what that's doing to your isometry. Because as I said, this is the fulcrum of the circle. So you want to be sort of conscientious about that, okay? So with that, I will turn this over to Dr. Schubenstein. Oh, sure. Okay. Okay, thank you. So I'll let you guys chat a little bit and dispel any myths or controversies. Thank you, sir. Thank you. Good, good job.

Dr. Jackie Breede

15-year-old patient

right knee instability

ligamentous laxity

MPFL reconstruction