All right, our last demo for patella-femoral instability is Todd Lawrence from CHOP and Chetal Parikh from Cincinnati, and they are going to go over their version of the tibiotubular osteotomy. Todd, can you hear us? Perfect. Yeah, we can hear you. Great. Thank you. All right, so we've already done a little bit of dissection here. Our patient had a previous all-epiphyseal ACL reconstruction, but we think we're going to be able to work around that pretty easily. We've done a little bit more of an extensive incision here than we would normally, just so you can kind of see a little bit of the anatomy. And then we've already taken down or released this anterior compartment fascia here and stripped the musculature off here. We are superperiosteal, so we're not below the level of periosteum over here. And of note, here in this dissection, Chetal, can you put a retractor right there? There's almost always a little leash of vessels right here. Those are your bad ones. Those are the ones you want to definitely make sure that you cauterize as you are doing this release. Here we're just going to, since there will be minimal blood loss, we're just going to make sure those are completely cut there and released so we can do that osteotomy appropriately. And so our next step is to identify the proximal, medial, and lateral borders of the patellar tendon. So in this specimen, that was already done for us as part of the alpha seal reconstruction, but normally we'll just kind of make a little slit in there and spread. And what you'll find is that distally here, there's a beautiful little space that you can get a hemostat into. If you're not in that easy space there, you're not in the right position. But once you've identified that space, you want to go distally here, as far down onto that tibial tubercle as you can, and then identify the lateral border of the tendon. So I will just kind of roll from on tendon to off, or off tendon to on. You can see, I don't know if you can see or appreciate the tip of that hemostat there, just poking through, and we'll poke through and we'll spread widely. And that'll define the medial and lateral borders of our tendon. We want to do that because we want to make sure that we get all of that tendon off, and then we're going to use this landmark over here, which is our medial attachment point of the patellar tendon onto the tibial tubercle as our starting point for our osteotomy. I like this guide system because it helps to ensure that I'm exactly where I want to be, my angles are pretty good. This guide system comes with three different angles that you can cut at, but the shallowest is a 45 degree angle. Sometimes I find that even a 45 degree angle, however, is a little bit too steep for my liking. And so, as we're putting the guide pin in for this system, which is put in with this little T-handle guide here, instead of having that be straight up and down, and I'll get my rotation based on where it is on the knee with just a slight little bit of knee flexion, I will offset this pin 10-15 degrees to kind of drop that 45 degree angle down to about a 30 degree angle sometimes. And then we put that guide pin in and that basically sets the rotation for our osteotomy. Then we've preset this, this is kind of like your organic chemistry set where you're building your outrigger onto your tibia. But if we can kind of zoom in here, we'll internally rotate so everybody can kind of see what we're looking at, what we're going for here. What I'm looking to do, our fixation pins that are going to hold this guide in place, one goes here, one goes here, and one goes down here, we want to make sure that those are not in our osteotomy site. And this is the cutting guide for our osteotomy. And I basically want to make sure that that osteotomy starts right there at that posterior aspect of the patellar tendon as it inserts onto the tibial tubercle. So that's where I'm going for first. And I take my first pin then, and I'm going to set that along the trajectory of this in there. And I'm going just to the far cortex but not really all the way through. And at this point, we can then dial this up or down subtly to make our osteotomy shingle a little bit longer or a little bit shorter. And so Chital and I were just discussing how long we like to make our little osteotomy shingle. I think we both agreed that we would shoot for it to completely taper out somewhere around seven to eight centimeters in terms of being able to, that's where it would come completely out the anterior cortex, but maybe not cut all the way that long. We're going to talk about some modifications of this osteotomy towards the end that we can do in terms of how we would change it if we're going to do a distalization or even a slight distalization. But for now, we're just going to put a second guide pin in here down. And this, of note, this harmonica, as I call it, it's about eight centimeters in total length. So we'll put another pin down here. Good. And then our final pin goes right in the center. And because this proximal tibia is not quite 45 or even 30 degrees and this pin is threaded, sometimes it tends to want to drive it in and increase the angle of your osteotomy. I'll just put a little finger behind here. Sometimes we'll have an assistant put a hemostat in there just so that I don't necessarily drive this thing all the way down to the bone or change its angle substantially as this pin goes in. Good perfect. All right, and then this guide can come off And this harmonica thing comes off And these are breakaway pins I don't always break away quite as easily as they should but And then don't forget to remove this pin it makes it hard to cut your osteotomy move that you get to remove that pin So now We're set up to actually do our osteotomy and we obviously want to protect all of our lateral structures over here So she's gonna retract there for us In a scenario where you're got a little bit of a tighter incision You definitely want to make sure that you're taking care to protect Your skin and your patella tendon as well so I normally put a Right there and then you're gonna use a nice skinny blade like we have here and there's a good bit of play In this cutting guide, so you can drop your hand a little bit more You can raise your hand a little bit more you can cut on the bottom side of this. You can cut on the top side of this Really just to kind of fine-tune Where it is that you're cutting? The key here is to make a nice continuous Flat cut without any kind of deviations. And so I'm going to score the proximal cortex I'm then going to go Full thickness cancellous all the way to the other side, but not through and Then I'll start in the center and go distal and the center and go proximal Not cutting all the way through towards the top on the other side. So since this is just makes a whole lot of Noise, I just kind of described it and then I'll just kind of do it for you Looks like we need a new battery I Was better And obviously you can see a little smoke coming off You want to get somebody to basically continuously irrigate during this entire process to protect your cut here All right, so now that I'm all the way to the far cortex I'm going to come through Some full thickness there I Until the osteotomy starts to kind of dip down posteriorly Right there. You don't necessarily want to go all the way over full thickness approximately Once you start I kind of stop once I get to the flare right there. Can you appreciate that? Let me let's bring this Up there and move this Over kind of how we're how we're stopping our osteotomy right there at the flare on the far cortex. We have already cut From a cancellous standpoint all the way across More approximately to here, but from a full thickness. We've stopped right there All right, so that's what we're gonna do with a saw we're now ready to pull these pins out I Mean it's all back one second because it's like we need to continue this cut up just a little bit further So I'm going to use my cut as the cutting block that can slide in here, there we go And we roll in here, let's just show this to peeps just a little bit say not quite all the way up So, there we go Great all right, so then we got two osteotomes Typically do this for quarter-inch osteotomes ones straight And one's curved and my first cut here is to come and say all right We're all the way across we're all the way up there Good And then I'm going to come right down and across Right underneath the patellar tendon Perfect and I go straight across for a standard Osteotomy if I'm not trying to distillize anything at all, and I'm really just trying to get the cortex And I want to go as far as the other side of the patellar tendon I Think we're there I Need a big like 3 quarter inch or 1 inch osteotome Perfect so now we know where we're headed and Then with my curved osteotome. I'm going to come in here. I'm going to find my Perfect and then you have another army maybe Or we can just bring your arm in here, yeah great, so we're going to find this cortical breach And we're just going to kind of do a curved sweeping Break or crack of the cortex coming between GERDES tubercle and the tibial tubercle And I'll usually take a bovie and come through this fascia right through here At this stage, but I think that our specimen is so Osteopenic we're going to have no problem. Just kind of cutting through with the osteotome But that's my goal is to get those two osteotomes to essentially connect And then we can yeah, it's already Perfect. I think we'll be able to use this guy and that can come out all right, so now is the moment of truth Kind of come in here. I do this by hand And it's just a little wiggle wiggle What I'm doing so now you can see that we've got an intact hinge distally we have completely Mobilized this proximally And we're ready to Try to transfer it up and over but before we do that. We're going to do one thing here Which is going to greatly enhance our stability of? Our final repair which is to elevate this periosteum Over here, so I've got a key elevator here Normally do this with a small Cob, but we couldn't quite find a small cob I think the key is working pretty well Obviously in a younger Patient this periosteal sleeve is going to be much more robust sleeve of tissue as well I'm just plowing right into the osteoporotic bone and make it work. And I will release this sleeve of tissue pretty far up, definitely up onto the proximal flare, definitely underneath the PES tendons so that they come up as one big complete sleeve of tissue during this whole process. And you'll see why I think that's important. Wow, it's just kind of falling apart on us here. It's an osteoporotic flap. Yeah, well plus we got a tibial tunnel up here which is not making our lives any easier. Okay, so you get the point. Big periosteal flap here. And so our next order of business is to move our osteotomy over. And so if you, if you remember your trig, and I normally just kind of do this by hand. Nice little crack there. If you remember your trig, if you got a 45 degree angle, it's times the square root of 2 as a lengthier hypotenuse. So that'd be for every 1.4 centimeters you move up the osteotomy site, you get about a centimeter of medialization and a centimeter of anteriorization. If you drop that angle to a 30 degree angle to get that same 1 centimeter of medialization, you only need to come up the slope about 1.1 to 1.2 centimeters. So we'll take our ruler here and we kind of set it down against the proximal aspect of the bone. I go to right to that corner and I say how much, how we looking there? About 15 there. 15? Or maybe 13 now. So you dial your osteotomy in based on how far you think things need to go, how far things are lateralized. And then we'll pin it in place. I would normally use a really skinny, like 0.045 inch smooth K wire. But for demonstration purposes, we're just going to use one of our old pins here if we can find one. Here we go. And I normally go very proximal here, somewhere way outside of where we would be. Putting screws in and just kind of temporarily pin it in place. Perfect. And then measure twice, cut once, check again. How do you like it? Yeah, we're 1.2, something like that. So we've done about a centimeter of medialization and then we can check our tracking. See whether you like it. What did you do to your patellar mobility? If you need to do a little lateral release, you can always come up here and release just a little bit of this tissue. If you feel like it's still tethering you. But I don't normally do a big open lateral release with these things. And so now we're to fixing. There are lots of different screw options you have for fixing these fractures. I prefer a 6.5 millimeter Kinsella screw to fix, which I'll over drill with a 4.5 millimeter. And then we'll drill deep with a 3.5 millimeter. I tend to like to not get any closer to my osteotomy shingle than two kind of cortical diameters. And I'm also trying to, as best we can, kind of hit this proximal cortex. Just kind of skimming it. So let's see what that'll do for us right there. I think we're good distance there. Perfect. It's good. And then once we've done that, I normally give it just a little countersink, just to help me get in. Go in 3-2 and then we'll just barely drill our posterior cortex with our 3-2 drill bit. All right, we got our screws here on standby for us. I'm looking not necessarily to get bicortical with this screw, but I'd like to tickle that posterior cortex for sure. A screw set I use comes in fives. We're going to do a four-five just because that's what we have here. That's measuring a forty, we can call it a forty-six, forty-six, give us a forty-six. So I had a question, the reference pin that you put, the first pin that you placed, you told us about the rotation, but about proximal, distal, does it matter, or you can move the guide over it so it doesn't matter? Yeah, you can move the guide over it. If you get lucky, and I always try to shoot to do it, in this case we didn't quite measure twice, cut once, good. Because here's our hole for our guide pin. Yeah. I'd love to be able to use that as a guide pin for this, for like initial hole for this screw. What I don't like, and why I tend to bias that hole a little distal, is that I don't like a stress riser in this shingle of bone above this screw. So you're gonna be, if you're gonna cheat, then cheat distally. Yeah, yeah, yeah. So I'm watching this come down, I don't wanna crush this cancellous piece down in there too much, but, in this, for this bone, I think that's a decent bite. Yeah, that's pretty good. So, perfect. And then, last little kind of closing, so we would put a second screw in there, I don't think we need to take the time necessarily to do that today. This would, this comes out. Because you've got a lot of exposed cancellous bony surfaces there, I like to put something on there to try to, one, get a little bit of hemostasis, but also to help with the healing. And so, a lot of manufacturers make this demineralized bone matrix stuff that you can, we'll just kind of inject in and around here, so I'll put some stream in down there, kind of smooth that into place. Some of these even have reverse phase carriers, so they actually harden when they get to body temperature. And then, all in and around through here. Perfect. Perfect, irrigate, irrigate, irrigate. It's already healed. And then, the last piece of this puzzle is, do you have a runger anywhere? Perfect. Is that there's almost always a tiny little sharp corner to your osteotomy right there. I like to take that off, just because it makes me feel a whole lot better, and I think it makes the tendon feel a whole lot better too. And then, here's our thing, and we have the suture. Perfect. So, I don't know how well we're gonna be able to demonstrate this, given how shredded our periosteal sleeve is over here, but I think a nice periosteal repair, from this periosteum up onto the side of here, dramatically increases the strength of your fixation. And I'll typically start distally, and sew this up, but I just wanted to show up here, at the very top, one thing that you can do, like if this osteotomy has crushed down, or if you didn't feel comfortable quite moving it over as much, is that you can grab a little bit of these tendon fibers, and kind of pull them over the top of your osteotomy site, in an attempt to kind of spread out that patellar tendon attachment distally. If you need extra length, in terms of that repair, you can do what's called a pie crusting. Do you have a knife? I know we had one before. Yeah, there we go, perfect. That looks great, Tom. You can do a pie crusting, which would be, boom, boom, boom. And a bovie on cut works really well for that. So, I think that's about all the tips and tricks we have. Any other thoughts or questions? If you have to do a distalization, how is it gonna be different, your cut? Yeah, so that's a great question. It's a great question. So, there's two types of distalizations I'll do. One is a minor distalization, and one is a major distalization. And I'll kind of break those down into, I wanna go three or four millimeters distal, or I wanna go eight to 10 millimeters distal. If I wanna go three to four millimeters distal, obviously, you have to taper your cut out completely, down here. You see that we didn't get our periosteum at all, but we also didn't even complete our cut anteriorly. We just kind of cracked it. Or sometimes you can just kind of plastically deform it. But if you're gonna distalize just a little, you have to kind of skim that all the way out. So, you skim that all the way out. And then the next piece, and this is kind of a tricky thing, is that instead of coming straight across with this initial kind of osteotomy here, I'll actually angle this up just a little bit. And what happens is that then, as you slide your osteotomy over, it's forced to come down. It's forced to come distal. So that this far corner up here kind of is now against this more distal corner there. So I think you can- So you're sliding down when you're sliding. Yep. So the osteotomy, instead of just doing this, is kind of doing one of these. And then if you gotta go eight to 10 millimeters distal, I will, instead of tapering this out towards that eight centimeter mark, I'll taper it to a stopping point at about nine centimeters. I'll cut my periosteum. You have a... Oops. I'll actually cut the periosteum here. Like I'll cut the periosteum like at eight centimeters. And I'll reflect that periosteum down so it's still attached distally. then I'll come in with our saw and make a step cut there and then however much you want to distillize take out a piece that big and that's it it's a really thin shallow two three millimeter sliver that I'm taking out I'm really not even full thickness through the cortical bone you just this is a as I say this is a attending only non-delegatable task because you don't want to go you don't want to plunge just down to where you've made this cut and then I'll take that piece of bone and as we pull this shingle down we'll slot it in up there and it'll help help to stabilize so that's a great question awesome any other questions or thoughts great okay

tibiotubular osteotomy

patella-femoral instability

dissection

cautery

patellar tendon

osteotomy

fixation