So now this is an 18-year-old male. Pain began one year prior when the patient jumped into a shallow lake impacting his knee with a longitudinal force. I think understanding the mechanism of injury is important. And he was having loose body symptoms. No effusion. Again, tenderness palpation over the site, in this case the lateral aspect of the medial femoral condyle. And no other pertinent findings. Here's our T1s, T2s, from the coronal view. And bone windows. Oops. All right. I'm going to stop it on that one. Hopefully I'll stop. Okay. Panel. Again, Yuta, you want to make a quick comment about the imaging? Grab the mic. »» Yes. So I'm going to start with the bone windows. I'm going to start with the bone windows. This is an unstable lesion. Can you guys all here in the back grab the mic? One sentence. Unstable lesion. There's fluid at the interface of the parent bone and the progeny. Progeny is largely ossified. There's violation of the articular cartilage integrity. This is your patient closer to the beard and mustache. And so this is going to be tough non-operatively. We want to address all the principles that Crystal addressed. And typically, there are times when things can be done arthroscopically, but you need to prepare the patient that this could be a small surgery first, which means that things are not salvageable. It's like a cotton ball rather than a cue ball, and you have to remove it and then do something later, which is either ACI or osteochondroallograft, or now MACI or osteochondroallograft, or it can be the big surgery first, which is an arthrotomy and either suture bridge or screws, and then you come back arthroscopically, and that can be to remove either the non-reservable sutures or the screws. Yeah, so unstable lesion, going to be probably a loose body sitting in situ. You can't put a probe behind it, the whole thing plunks out. You know, this looks to be fairly small, 15 by 15 or so. In my hands, I haven't been super excited with my repairs on lesions that are this small. I think it's not compression over a large enough area, and so I've seen some of those repairs fail. So for a relatively small, unstable OCD, I would be probably planning scope, look at it, but then I would probably do an OCA for this, and alignment x-rays to assess if you need the numbers. Real quickly, nothing else to add about the technique. My only comment is setting expectations with families from the start about, you may need a minimally invasive procedure, you may need the full ACI or osteocondylograft, so setting that stage with the families from the beginning so that they expect it might take two or three procedures to solve this is really important. Awesome. Excellent comments. Thanks, everybody. So this patient underwent curettage, proximal tibial bone grafting, and O production internal fixation with headless screws, very similar to one of the cases that Crystal showed. Here's the images. You can see how this is clearly an unstable lesion. Without even probing it, you can see it. Here's what it looks like on the inside. So this is that tissue that, we've used a lot of different terms for that tissue. I tend to think of it as like a cartilage onlaga, something in between that articular epiphyseal growth cartilage versus normal bone. So whether it's necrotic, whether it's still sort of a cartilage, it's hard to say. I'm going to stop there. But I think it's important to know it's not normal tissue. It's not going to support the overlying bone and cartilage. And it's something that is going to make it hard to heal across that area. So I think it's super critical. I think this is a big point of what we've learned from all of our basic science stuff, both with the animal studies and with our MRI studies. I think a really important key is just getting that stuff out and then filling it with good, healthy tissue that not only provides structural support, but provides that healing active bone. And so I think, not published data yet, but we're working on it. We have had really good luck at the University of Minnesota in following these patients with subsequent post-op MRIs and getting these to heal. Another important thing is to note, you can see the articular cartilage. Obviously we're puncturing the articular cartilage with our screws, which I would love to not do. We do it, whether we do it with a suture bridge or with screws, we're somehow affecting the cartilage. At some point, hopefully we'll figure out another way to get this to heal and protect that cartilage. But otherwise, that's normal cartilage. And if that thing heals, that's better than anything else we can do. And so we have been very aggressive with trying to save these fragments as much as possible. So here's the post-op. I'll skip this stuff so we give you guys time for questions at the end. I think one thing that's really important and why we also feel that the MRI is very helpful, it is not uncommon to see this on x-ray. So this is actually a patient with no symptoms, but you can still see that OCD lesion there. The screws and everything look fine. We don't see any evidence for loosening. So we take the hardware out and then we take them back and get imaging. And you can see how there's already some bridging here at four months. And we use this as part of our protocol in terms of thinking about going back to activity. So not only do we do the physical part, but this part as well to make sure. And then the patient came back for another reason, or I think maybe in this case we had him come back just for a routine follow-up. And you can see the difference on what it looks like on the bone windows at 1.5 years. So that can continue to fill in. So this patient now has normal articular cartilage, except for the area where I poked some holes in it to put screws in. I think that's probably better than anything else that we can put in there, so for whatever that's worth. All right. Thank you very much, everybody. We have about five minutes maybe.

knee pain

injury

unstable lesion

arthroscopy

healing