And can they see the instrument trays right now, if you can see this? So I'm just going to point out, for OCD fixation, most of the time, if you don't need to bone graft by opening the trap door or debris bone, you can put the screws in arthroscopically. And there are some nice retro-articular bone graft delivery devices where you can put in BMAC, demineralized bone matrix, behind these lesions without opening them up. But in lesion, let's assume this is a stable OCD, intact articular cartilage. We've already placed one screw that we're going to change positions on it, but we're going to show you the steps of this screw. I'm going to talk you through the screw sizes. They're typically 25, 30, 35, or 40. This Arthrex, I have no disclosures or conflicts, but this size, this is an Arthrex company. There is a 25, a 35, and a 40 diameter. The advantages, obviously, is size. I really like the size of the 25. The downside to the 25, it's an Allen driver instead of a star driver. And sometimes in harder bone, especially in the femoral condyles, the screw will strip, that Allen screw will strip. With the 35 and the 40, it's a star driver, a torque driver, and so it's almost impossible to strip that, even with metal composition. So just be careful if you're using their micro set that you can strip it in soft bone or hard bone. So once again, you've got a micro for the smallest 25 Allen driver. You have, I'm sorry, micro is the 35, the standard is the 40, and then over here is the mini compression set. The mini is the 25 with an Allen driver will strip. Each set has everything you need for drilling, depth gauge, all in the same set. One other tip about these is sometimes there are three different guide wires, all of different diameters, and sometimes they get mixed between the sets by the sterile processing team. You want to make sure you get the right guide wire because they're not compatible with each other. The next size up is too big for the next size down, so keep that in mind. So we're going to use for this one, here is the standard one, excuse me, we are going to use the mini one, not the micro, and that's over here. Here are the choices. This is 35 set. I think everyone in the room knows how to put cannulated screws in, but here's just some tips for arthroscopic placement. I typically try to place the screw and my portal such that I'm pretty normal to the joint surface. Now, I can't flex and extend the specimen, so I'm not going to get it perfectly normal, but I try to pick a portal such that my screw and my guide wire are pretty normal to where they're in. So I've sort of picked a portal here. You can see the first screw is pretty normal, but I can't move this knee. So we're going to put a screw a little bit higher, and in the perfect world, I'd flex this knee just a little bit. Maybe Henry can flex this knee, even though it's not cooperating. And finding a portal, getting your guide wire in the right spot, and so let's say we decided to put another screw there, and we kind of look at it from multiple different planes, and at this stage, I look pretty normal there, and so I'd probably accept this. I might flex the knee a touch more. I'm going to have Henry hold the scope for a sec, and I'm going to advance this wire. Usually, I put these in about 26, 28 millimeters. If it's an open growth plate, I'll kind of plan with my preoperative plan not to get into the growth plate, and the same thing with my screw size. So we're going to put that one in a wave, and there's a depth gauge and a dilator, and they actually both work equally well. This is just the blunt dilator, and it'll actually expand your hole, and it'll make a little bit easier when you're putting your drill down, and you'll be able to see there. So you can see the dilator. It's kind of a soft tissue dilator, and in addition to the soft tissue dilator, you actually have a depth gauge, which is right here. It's very similar to the dilator, and I usually just go right to the depth gauge because I can dilate and get my depth gauge, and so this one is showing me I'm in... Looks like I'm in about 20. So that's in about 20 millimeters. I'm going to advance that in just a little bit further because I don't want to back it out when I'm putting my screw in, and my next step then is going to... Next step is going to be to over-drill this a little bit. And Henry, I hope we didn't bend the guide wire when we were bending our knee. Okay, drill. I usually just go through the cartilage, and the first mark on this one is 12. You see that first line? It's a 12-millimeter. See right there? It's got a 4-millimeter mark, so I'll go into 12, and that's probably far enough. Now, this is soft bone. It may pull my guide pin out. Yeah, there's a lot of friction in this system. I'll need a clamp to... You got a clamp to pull that out. It's stuck in the drill. So when you're putting these screws in, and you're near the physis, do you rely solely on your preoperative planning, or do you ever bring Floro in to check your trajectory or the length, the depth, or position within the lesion? Yeah, I have the mini C-arm in the field, and so I use the C-arm a lot, but I definitely preoperative plan, and I've got my images up in the OR, so I can look at my preoperative plan, and I can also do exactly what you're saying, is I can check the C-arm, make sure my screw position is okay, and I definitely check the screw position at some time. So I'm just going to pick... We're going to pick a 16-millimeter screw, which wouldn't be atypical. It might do a little longer, but we'll just put a 16-millimeter screw for these purposes here, and I put the screw on the guide wire, and then I add the screwdriver later, and I'll... In some cases, I may power this in, so I've got this on a very, very careful power driver just to get it in quickly, and the final tightening I'm going to do with the manual screwdriver. I have a lot more precise control over that, but these are very fine threads, machine threads, and so it can take a while to put them in by hand. So I'll go to about there, then I'll take the manual screwdriver, and this is a tapered device, so theoretically, you're changing the diameter of the hole as you advance it, and so in theory, you don't want to back this out, because you get maximal compression when you back it out... I'm sorry, when you advance it. When you back it out, you lose that, and so I'm constantly looking here, and this is where I may change the position of the scope, because I want to make sure this is fully recessed in the subcolonal bone, and I'll back out, and I'll look, and you'll start to see eventually a little bit of bone, especially in young bone, it stands out really clearly. Usually, when the flutes are almost completely buried or close to that, you're probably in subcolonal bone, so here we're on the medial form of condyle, the average thickness here is probably about three to four millimeters, and you can see right now where the flutes are, I look like we're starting to get into the subcolonal bone. So I like that, it's seated, I prefer not to have these in the cartilage. Occasionally I'll do it in a thin piece of cartilage that I fix, but usually I use a different fixation device if I have to anchor cartilage to bone. If I've got no CD with a big piece of bone behind it, I think these screws can be countersunk into the bone below the cartilage, but obtain adequate purchase in the fixation. So I left this first screw over here intentionally proud, because that's too high, and Henry's doing a nice job of showing this from a couple different angles, and I'm going to try to slowly back out this other K-wire, and if I can, we'll just put it right up that other hole. Henry, if you can give me just a sec. Maybe back out, give me slightly, there we go. Now drive in, and we're going to put this up the hole again. And this is a different hole. And you can imagine if you would flex and extend the knee an arc of 20, 30, 40 degrees, you can get the guide wires and the screws more perpendicular to the cartilage. But this one was intentionally left high, and if you look at that, it's too high. And I may go back and make a few adjustments or have the resins kind of go a quarter turn at a time, half turn at a time. Look at it, still a little proud. A little more. Getting closer. Still a little proud. But getting close to where we can see the subconval bone. And there I think we're just seeing that subconval bone. The color's starting to change between that whiter cartilage margin and the slightly yellower. And clearly we're in bone there. And so now I just take a final look at all the screws. And this is where I think the C-arm's really critical. You like every view on your C-arm. And there we have it. Another tip, these are very flexible thin wires. And most of the time I have the resins grab them with a needle driver and unwind them and take them out. Because if you bend them just a little bit, they'll shear off inside. And so you see I've grabbed this with a needle driver. Because if you put the power driver on here and torque it too quickly, you can shear the wire. Even a little bend on this, it'll be a weak point, it'll shear the wire. So I usually grab a needle driver and just have the resins slowly unwind it with a needle driver. And gently apply a little traction and unscrew it and pull it out. Because even there, I might even put a little hair of a bend on that. So it's pretty easy to shear those off if you're not careful. So, Henry, any comments or suggestions? So does the actual thickness of the lesion you're fixing affect your decision for which screws to use? It does. Sometimes there's not enough bone, I think, to use these screws. I think I have to have at least 3 or 4 millimeters of bone to get these screws in. Because if it's a millimeter or two of bone, I worry that the purchase on these is going to be limited. And I might have to leave them a little more proud than I might want. But if I've got reasonable OCD bone, you know, significant 3, 4, 5 millimeters or more apparent, or rather progeny bone thickness, I think these are a great fixation tool. You know, we use these and we talk a lot about the utilization of compression for osteochondritis desiccans. But will you use this technique for both traumatic osteochondral fixation as well as for compression for an osteochondritis desiccans lesion? Yes. And I think these work very well on the patella and on lateral formal condom when you have those sheared off injuries. And occasionally, you know, we see them in other locations on the knee. But this can be a very nice screw for the patella. The one challenge with patella sometimes is you may get a fairly thin wafer bone. You may not have 4 millimeters of bone. You may only have 2 or 3. But you tend to have at least 4 and sometimes 5 millimeters of cartilage, 3, 4, 5 millimeters of cartilage. But I'm always a little worried about these being too close to the cartilage. If there's any question about that, I'll go back in and take them out, say, 5, 6 weeks later. And by that time, if it's acute osteochondral end drive, yet to have one not be fully healed at 5 weeks later when I go back and take the screws out. Well, that really goes right into my next question was, do you routinely take these out? For patella fixation, I do. Unless I had a really large piece of bone and I'm convinced they're fully recessed in bone and will never break through the cartilage and score the trochlea. OCD lesions, I usually feel that the OCD fragment parent and progeny bone, the progeny bone is big enough that I can recess them in bone. I never have to worry about them scoring the tibial plateau. I will say that Andy Penick showed me a case a couple of years ago where they had a patient who's healed in OCD and about 14, 15 months later, one of the screws backed out. And so that's made me rethink things a little bit because I think Andy takes most of the screws out when he thinks the lesion is healed. But I don't do that routinely, but Andy's experience has made me think about that a little bit. So it's always great to get good access, in particular to these osteondritis desiccans lesions. But what's your philosophy on whether you graft it behind the lesion? Do you hinge it? How aggressive? And then what's your preferred drilling technique? Yeah, I prefer not to open up normal cartilage, even if it's a bad looking OCD with a T2 high signal. I will occasionally do that, but if the cartilage is intact, but I push on with a probe and it blots like a trampoline, I may go ahead and open that up, remove some of that necrotic bone, put real bone graft in there, and then add fixation. But in cases when the cartilage is completely intact, I like to leave intact cartilage intact. So in those cases, I will put screws in, which does violate. I did drill through the screws to do that. But I will put screws in, but not take the fragment down. But I will, in some cases, do a retro-tick for bone grafting, where you place a guy, a drill, usually a type of a flip-cutter drill, that you make a small little hole behind there, and then you can deliver BMAC, or demineralized bone matrix, or a slurry of both. In addition, you can also add a little radiopig dye, so you can see exactly where your BMAC, DBM matrix is being delivered. And do you ever, what, you know, osteondrostatic scans, sometimes radiographic healing is very challenging to really see, and so many times, you know, I think about MRI, do you get a CT scan? What's your protocol for determining healing? Great question. These are titanium screws. You will get an artifact, but it's not near the artifact. I've used stainless steel screws before, and the artifact is so big that you really can't assess healing at all, I think, in most cases with an OCD. With these, you can get a bit of a representation, perhaps, of the healing. But you are going to get a little artifact, but it's a pretty small artifact, and sometimes the MRI will help you make that decision. I look at the x-ray, is there healing at that parent-progeny interface, any healing bone at all? CT scan, I think, has the same problem, because the screws in there, you may get enough artifact in there that it's sometimes hard to assess that parent-progeny interface. And so I'm not sure what the perfect test is. MRI has an advantage, but CT scan has the advantage of really seeing bone detail better. But the artifact in here is sometimes enough, but the CT scan advantage is harmed, if you will, by the presence of metal in the metal artifact. Last question, but we've had some philosophical discussions about changing in practices, changing clavicle fracture fixation. In the last 10 years, have you changed how aggressive you are, or lack thereof, with trying to provide compression in these lesions? Yeah, I've become much less aggressive on clavicle fractures, and now I've become more aggressive on adding fixation in these. It's rare that I've regretted added fixation, especially if there were signs of instability on the MRI. And the MRI helps me as much as, what does that bone look like? What's the parent-progeny interface? How discreet do they look? And if there's a wider necrosis and a very distinct margin between parent and progeny bone, even if the cartilage is normal, it's not blottable, it's motionless, I'm much more likely to add screws, and increasingly I'm thinking more about adding some type of biological demyelinized bone matrix, BMAC, and a retroarticular replacement without violating the cartilage. But I think the minimally invasive, low risk of these things we do has affected that a little bit. You know, to place screws and retroarticular BMAC through a percutaneous drill hole is, I think, minimally risky in many ways, and I think potentially adds to the biological healing, in addition to the mechanical stability you get from the screws. Great. Thank you. All right. Thanks.

arthroscopic fixation

osteochondritis dissecans

screw sizes

surgical instruments

C-arm