So I'll talk about some treatment updates, how we apply all of this. So I have no pertinent disclosures. So Mark and colleagues had published this kind of outline looking at treatment of OCD, and I think this is a really good algorithm when we're treating these patients. Really we'll move from kind of determinants of stable and unstable surfaces today and really talk about treatment in terms of whether the cartilage overlying this is salvageable or unsalvageable. So we think about our operative treatment pathways, again, kind of the immobile lesion, intact cartilage. We'll talk briefly about drilling techniques. And then most of the talk is more about the mobile OCD and deciding is this salvageable or unsalvageable cartilage and what repair or salvage techniques do we have. So first the immobile OCDs. So these fit into the rock classifications of being a cue ball, shadow, or wrinkle in the rug. So this study was mentioned earlier, looking at Ben Hayworth's randomized controlled trial of transarticular versus retroarticular drilling. There had been a prior study to that that Lucas Moynihan had led a systematic review. And both of these together show us that whether you choose to do transarticular or retroarticular drilling, either of these are very reasonable techniques that result in good overall outcomes and healing in the long term. Perhaps transarticular drilling in the RCT showed slightly faster healing, but at a long term two year follow up, similar healing rates between them. So I thought I'd give you just a few pearls. It sounds very simple. Just drill the immobile OCD. But a few little technique tips for this. So I like to do these in a leg holder. Really especially for the medial femoral condyle OCDs, you've got to be able to give yourself plenty of space and whoever you're working with to be able to drill this. So I find this much easier to do in a leg holder as opposed to just supine on a flat top table. So maximally abduct the well leg again, giving yourself as much space as you can to work on the medial side. And then the mini C-arm I have enter from the lateral side for medial femoral condyle OCD drilling. This is a three by three drill guide that I use and typically place a first K-wire within the epiphysis in a center center position in the OCD. And then I assess the coronal and sagittal plane orientation of the OCD with the idea that I'm trying to move perpendicular to the OCD, specifically in the lateral plane. So you can see in that kind of middle image, basically established what is kind of perpendicular directly to the OCD. And that's that as I move anterior and posterior, I'm covering the whole lesion as opposed to being oblique to it. And so I typically keep two K-wires in place and then drill with the third. If you've done these before, you'll find that you do get a little bit of metal debris going through the guide. And so kind of wipe down the K-wire each time to maintain it nice and cool as well as not to tattoo the skin. And then in our clinical practice in Atlanta and others, we've looked at kind of supplementing this with any kind of bone grafting. So we may or may not use BMAC, depending on the age of the kid. Now I'd say really criticize your post-op radiographs. You can actually see these drill paths pretty well. So this is a kid kind of on the AP view. You can see the shadows, making sure have you covered this whole OCD and then again making sure that I'm fairly perpendicular to the OCD with drilling on the lateral and have covered it. Post-operatively, typically people keep these kids touchdown weight-bearing for six weeks and a neomobilizer for four weeks. They start PT post-op day two, working on range motion and kind of non-weight-bearing strengthening. I do typically check their vitamin D levels. You'll be amazed at these kids, at least even in the South, who come in with vitamin D levels of nine. So check those typically and then supplement them depending on their level. You can also do weekly supplementation, which I would say in the pediatric population may be a little more reliable than daily supplementation and tell them return to impact sports is typically four to six months pending radiographic healing. Then you monitor with serial x-rays, looking at nice overall healing. You just showed several great examples of that. So then we move into the mobile OCD, and I think this is really kind of the hard treatment algorithm is deciding what is best for these kids and what is ultimately going to have the greatest rate of healing. A word of caution, I would say, about debridement and marrow stimulation. Although it's technically simple with good early results, the fiber cartilage lacks the integrity of hyaline cartilage. Really I feel like in the discussion of OCD, there's really limited application for marrow stimulation alone as a typical OCD size is more than two centimeters. There's typically a fair amount of deficient subchondral bone. There are also single stage cartilage restoration procedures. Again, I would say there's minimal application for these in the setting of a failed OCD given the significant bone loss that's typically present. So amongst these, I have to kind of divide them into what we think are salvageable cartilage or unsalvageable cartilage. So we'll start with a case. It's a 15-year-old male soccer player who plays on an elite team who has had two months of knee pain. And he walks into your clinic and plays soccer seven days a week and is on a pro trajectory at this point. And this is the x-ray you get, which is a little disheartening. And you know you're about to walk into a room with a really long conversation. I'm really amazed at the number of kids we're seeing with more than multifocal kind of OCDs. They have a big trochlear lesion and a medial femoral condyle. They have medial femoral condyle and lateral femoral condyle. So you can see kind of large lateral femoral condyle OCD as well as medial femoral condyle OCD, certainly with impending instability, large cystic change, fluid signal behind the lesion. And so this is his scope image. His lateral femoral condyle was actually intact and got drilled. His medial femoral condyle, you can see here, so large unstable lesion. Those are scope pictures, and this is with it open. So large cartilage. There was some bone on the back of this fragment. And so this is an example of what I would kind of term OCD repair. So in the top left-hand image, you see obtaining distal femoral autograft. So this is a nice way to obtain bone graft within a single incision. So even in the skeletally immature kids, you can get a C-arm image, make a cortical window just proximal to the physis, and harvest cancellous autograft there. You debride back, and this is the most important part, is debridement and preparation of the surface behind the OCD. So there's typically a ton of fibrous kind of nasty material back behind the OCD. You want to debride all that back to good bleeding cancellous bone. And so you'll always be amazed. It's more bone grafting than you anticipate after you've removed all that kind of necrotic bone. And then in this example, this is using a kind of metal headless compression screw to repair this, again, with a sizable piece of bone on the back of it. And so this is him two years post-op. His screws had previously been removed. His lateral femoral condyle and medial femoral condyle OCDs are healed, and he went back to playing, and certainly an ideal outcome for a difficult problem. When we think about fixation strategies, I think we're certainly evolving. We talked a little while ago about suture bridge fixation. Kind of metal headless compression screws are a good option, but they're dependent on osseous structure. And a lot of these OCDs may not have a big progeny bone component to them. They typically necessitate hardware removal, and they have the potential, if a little bit prominent, to cause adjacent condyle injury. And then bioabsorbable implants, I think, certainly can have some applications, but we know that we've seen lots of consequences of those as well. They can loosen or cause synovitis or cyst formation. And so really the question is, is there an alternative fixation strategy for these? So this is a 15-year-old cheerleader with knee pain and swelling. You see she has OCD, which appears to have good significant signs of impending instability. There is a large progeny bone fragment on this. And so here's her scope image. So overall, what I would consider to be salvageable cartilage, but failing around the periphery, you can easily stick a probe in it among this and just lift it up. And so here are her scope images. Again, a large condyle injury here. So she had a similar OCD repair, but rather than using headless compression screws, instead did a suture bridge construct. So taking, in this case, bicorral suture through suture-based anchors, and then passing those, and then compressing across the lesion. And this has the benefit of not needing to go back to take these sutures out and providing good compression across the area. This is a kid I did recently. He's a 12-year-old who had a stable lateral femoral condyle OCD, but a large unstable trochlea OCD. And so you can see that in these images. And this is a big problem when you're 12 years old that I don't think we have great solutions for. So you can see his big trochlea OCD, where the medial margin of his trochlear OCD, the cartilage, is present but unstable. You can stick a whole probe under that. On the lateral half of the trochlear OCD, you can see his loose bodies in the lateral gutter. He had just recently developed mechanical symptoms, and so this is the kind of gross picture of it. His lateral femoral condyle was intact and got drilled. And so this is another one with that OCD repair. So again, preparing, elevating the cartilage, debriding all of that, getting down to good cancels, bleeding bone, taking distal femoral autograft. And then given the size of this, I used a non-absorbable tape-based sutures, which will ultimately go back and take out. And then we'll move on to unsalvageable cartilage. So what do we do in those cases? And typically, these tend to be a little bit of our older teenagers. So this is a 17-year-old female who came to me with four to five years of bilateral knee pain, slightly overweight. You can see she's nicely in varus alignment through her medial femoral condyle OCDs. And she has large, unsalvageable, once we got in with the scope at least, determined unsalvageable OCDs. So as compared to the previous x-rays where I showed you kind of disruption of the cartilage all around the periphery, but good overlying cartilage quality, this was kind of fragmented, frayed, not ideal salvageable cartilage. And so then we really have the option of what are our techniques. We'll kind of talk about two, kind of osteochondral allograft transplantation, and then cartilage-based procedures with bone grafting. So this is an example in her, given the size, did an osteochondral allograft. I would tell you, looking at alignment is really critical. We didn't talk about this earlier with drilling cases, but in the standard workup of OCDs, I would encourage you to get standing alignment x-rays on all of your patients. You'll be amazed at the number of kids who may look straight, that they're perfectly in varus right through the middle of their medial femoral condyle OCD. And in these skeletally immature patients, you have a unique window that you can consider guided growth through epitheliosis, whether with plates or transficial screws. And so unloading that area can be important. And certainly when you're looking at salvage procedures, similar to you would with osteochondral defects in adults or medial lateral compartment arthritis, unloading osteotomies are critical to the success of these. And so she got a high tibial osteotomy to unload her to the base of the lateral tibial spine. And this is her one year out from her OCA and HTO. This child's a little bit different. So this is a 16-year-old who's had one year of knee pain and mechanical symptoms. And so you see this large OCD, nearly the entire width of the lateral femoral condyle. He is, of course, in valgus. And so when he got in, this is a fragmented OCD, the multiple pieces we took out. And he had a really large bone component. You go back and look over here, you see how such significant depth. And so my concern was with that amount of depth, even doing an osteochondral allograft is going to become a really deep plug if I did that. And so instead elected to bone graft him at this stage. So you can see we've done an open approach, debrided out the base of the lesion, packed that full of bone graft, that's fiber and glue that's over the top. And then came back, given that we had solved his bone stock problem, came back to do a distal femoral osteotomy to unload him. And this is using MACI as a technique to restore the cartilage then. And this is him two years out from a DFO with bone grafting and MACI. A little bit about MACI again. MACI with OCDs is very different than MACI, perhaps, with a pure chondral defect. And so you really have to treat the bone component, as we've talked about, with the definition of an OCD. It's that subchondral bone problem that starts first. So don't neglect the bone component or everything else will fail. You really have two options for treating this. You can do what we just showed in the first image, which is a two-stage bone treatment where you bone graft initially and then come back to put a single cartilage implant on. Your other option is to take a cartilage biopsy and do it in a single stage later with bone grafting or MACI sandwich technique. So people often ask, well, how do you decide? Who gets the osteochondral graft? Who do you bone graft and then do cartilage treatment for? I think it's really a discussion with each patient and family. Sometimes patients have preferences. Sometimes I have preferences. And so I'll kind of guide the decisions, what we do based on that. I think MACI with a cartilage membrane is a little less tolerant of the less compliant teenager. So if I'm concerned about compliance with weight bearing, then I definitely move more towards osteochondral allograft. If I think I'd rather do this all in a single stage, certainly an OCA is reasonable. If I have a really deep, unstable OCD, though, then I'll consider a two-stage technique. Ultimately, in the long run, the return to support rates, I tell the families, are the same. So what do we take away from all of this? So drilling of the immobile OCD, I would say, sounds simple. It is a simple technique. But you really want to make sure that you are careful to ensure complete coverage. I've certainly seen OCDs of my own, OCDs I've seen from other people who it's really well healed in one area. But if you go back and look at the images, kind of the posterior aspect of the lesion wasn't drilled. And that isn't completely healed. So just being careful to drill completely. OCD, debridement, bone grafting, repair is a good technique for the mobile OCD with salvageable cartilage. So I think the big takeaway should be that the native cartilage is ideal, and we want to preserve that at all costs. So if you have good native cartilage, considering a repair technique to preserve that. But however, sometimes with these OCDs, fragment salvage is just simply not possible. And so considering a chondral resurfacing, using chondrocyte products in conjunction with debridement and bone grafting, or treating both the bone and cartilage with osteochondral transplant. And then lastly, I would just harp on again, standing alignment x-rays are really important. So make sure you're getting those any time you're treating an OCD. And consider guided growth versus unloading osteotomies in the treatment of these patients. Thank you.

OCD treatment options

drilling techniques

repair techniques

native cartilage preservation

osteochondral allograft transplantation