That was my segue. Ankyloses, so there's an unclear instance in the general population. The etiology, a lot of the osteochondral or osteochondral lesions occur for acute or due to acute or remote trauma, about 6% of patients have a history of ankle sprain, obviously common with patients who have fractures, and as I said before, about 16 to 23% of patients undergoing lateral ligament construction have a true osteochondral defect. There's a number of reasons that patients can get this, including repetitive microtrauma, there's a genetic predisposition, osteonecrosis, vascular dysfunction, alcohol abuse, and lower limb malalignment. Osteochondral lesions, the tale is representing 4% of all OCD lesions, they're most common in between the second and fourth decades, and there's a slight male predominance, again in the bilateral, about 4% to 10%. There are a bunch of classification systems, I don't find them terribly useful, other than, you know, you're going to see a variety of different lesions, and I'm going to talk about specifically the difference between osteochondral, like an osteochondral lesion, osteochondritis desiccans, and a fracture. So this is what I would consider a true osteochondritis desiccans, where you have both an osseous and cartilage fragment, and this may be something a patient's had for years or even potentially even born with. I'm not exactly sure what causes these, it may be vascular, it may be congenital, it may be trauma related, but you can see it's a fragment that's kind of sitting here in situ. I would argue there's a difference between that and this, which is an osteochondral lesion of the talus, where here you have a cartilage injury, which has led to a cyst formation. So this could be acute, this could be chronic, but this is, you know, doesn't necessarily involve an osteochondral fragment. This is a cartilage lesion, which has led to a cyst. And then this patient, which is someone different, which is a patient of mine who had acute ankle sprain, and you can see here over the lateral side of the talar dome, she has acute osteochondral fracture. So a lot of times all these three things get lumped together, they're probably three different things in terms of etiology and potentially how we treat them. So what generalizations can I make about them that you might get asked? So medial lesions are more common, okay? So they represent 62% of the total. They tend to be deeper, larger, and cup-shaped. Only about half of these patients have a known history of trauma. They tend to be less symptomatic, and the true incidence is unknown. And as I said before, these are the ones that are associated with lateral ankle instability. Lateral lesions represent, this one study, 38% of the total. These tend to be the ones associated with the acute trauma, so like in the girl I showed you before, she had an acute injury. So the acute osteochondral fracture tends to be on the lateral side. They're more likely to displace as well. This is a study which basically kind of divided, they had over 400 osteochondral lesions and tried to divide it into these nine quadrants of the talus. Again, the most common is going to be medial, not that they would subdivide, but a central medial lesion is your most common. Again, those tend to be chronic. And then your lateral lesions are less common, and those tend to be more acute. Again, there's no 100% here. You know, these are, but if they ask you most common, it would be a medial one, and again, those tend to be chronic. So what symptoms do you have? Chronic ankle pain, activity-related or intermittent swelling, catching, grinding, clicking, locking, and the sense that the ankle is giving way. So just to kind of reinforce this, so if you see an osteochondral lesion and the patient says that their ankle is giving out on them, you look for a cause. So here's what happens in chronic ankle instability. When they're walking or their ankle gives it out, they end up putting more pressure on the medial aspect of the talus, and the pressure actually shifts medially. So that's kind of the mechanical, a lot of the mechanical etiology of these types of problems. So if you had to address this, or if they asked you what you were going to do, you'd address both. Okay, you wouldn't just say, oh, we'll just fix the instability. This is something that you would probably, like I said, address both the cartilage lesion as well as the instability. Conservative treatment is, again, how you start off with these, particularly for asymptomatic lesions, acute nondisplaced lesions, and this includes rest, immobilization, and activity modification. This tends to work better in younger patients, and healing and resolution tends to be more difficult to predict in the adult population. In one meta-analysis, conservative treatment had an excess rate of about 45 percent. Operative indifications for these include symptomatic and those that have failed conservative management, unstable displaced acute fragments. So again, that picture I showed before with the acute osteochondral fracture of the lateral talar dome in the sprain, that's one I would argue you would fix acutely, because that's basically like a displaced intra-articular fracture. And then, again, you must address malalignment and instability if present. I don't know that they're going to go into too much depth on how to treat these. I mean, we can't even agree on our service necessarily how to treat them. But for, I would say, probably the standard of care for smaller lesions is a microfracture or debridement, which is where you remove any of the cartilage or necrotic bone that has not healed, and you're drilling holes into the bone to get it to bleed. That then heals with the scar cartilage. It's not normal hyaline cartilage. If you do have an acute fracture and it's a big enough piece, you can do an ORIF. If it's a bigger defect, then you're talking more about doing some sort of grafting procedure, whether it be an allograft or an OATS. This was a combo of bone graft as well as some de novo, which is a juvenile particular cartilage allograft, but those are for bigger lesions. They may ask, you know, is there a critical size where you kind of shift from just doing a scope to doing one of these grafting procedures? There's one study that suggests that basically 150 millimeters or a 1.5 centimeter defect was kind of their critical size cutoff where the patients did considerably worse with just an arthroscopic procedure. So again, for ankle OCDs, it's about 1.5 centimeters. Might be something that they ask you. And then if you are going to scope them, things that they do often ask about in the OATs, you know, where are you making your portals and what are the dangers? So when you make an anteromedial portal, you go medial to the anterior tibial tendon, you have to worry about the staphenous vein. The most common injury, though, is when you make the anterolateral portal and the superficial peroneal nerve or branch, but it's almost right over where you want your portal to be. So that's the most common injury when you have an anterolateral portal, and this is lateral to the peroneus tertius. The only other thing I would say in terms of access, if they ask you a question about how you might access it, if you have a posterior lesion, at least historically, if you're going to treat these with a grafting procedure, you have to do a medial malleolar osteotomy to gain access to the lesion. Otherwise, you can't, you won't be perpendicular to the lesion when you're putting your graft in. That's all I got.

osteochondral lesions

ankle

acute trauma

ankle sprains

fractures