Hi, I'm Volker Muser. I'm from the University of Pittsburgh and today I'll be discussing slope reducing HTO going above the tubercle. These are my disclosures. I am a consultant for a company who produces plates for osteotomies. So I'm going to start by just showing you a case, maybe not the most typical case in an orthopedic practice, but very typical for this particular procedure we'll be discussing. There's a 30-year-old male. He's sort of a laborer, played lots of basketball in his life. Now it's a weekend borea. Had multiple, multiple ACL reconstructions and a lot of allografts, as you can see. So you can obviously pinpoint the whole misery on allografts, yet once you see the images on the right, you can't unsee it. So you see an anterior subluxation. You see a good 15-degree slope and a relatively normal coronal alignment. Relatively normal. They also had a history of infection from some bone tunnel management. So you need to decide whether that shies you away from doing any further surgery or not. To me it's helpful to know roughly what the IKDC is. This is a pretty crappy number. 15 is very, very bad, but it goes along with a knee that's devoid of meniscus, beginning arthritic, subluxed, and unstable. So it does make sense. Before I tell you what to do with this case, I just want to go a little bit through what these osteotomies are like. So anterior closing wedge HTOs are nothing new, of course. This is something that's been used since, I don't know, the 80s or maybe earlier than that in Europe a lot. You should all read Bruce Ryder's editorial in the February issue of, I don't know, 2019 or something like that. And it's used in the veterinarian literature a lot. But we use it currently in second revision ACLs. We consider it if the slope is high. If there's a neutral coronal alignment or a minimal varus, if the slope is greater than 12. You should be careful if that particular patient has the high slope and hyperextension, which is rare. But if they do, you should know that with a slope reduction osteotomy you get a higher number of hyperextension even. You should probably not do this procedure if they have a huge varus deformity and also not in grade 4 by compartmental osteoarthritis. It does not work. Here are just some studies. So this is a two-stage type of study, a report from Germany from Ralf Acoto in 2020. So they did 22 patients. They had about a three-year follow-up, did an HTO first and then followed ACL-LET. They changed the slope from 15 to 9, so they left it in a little bit of a higher slope, but it's a nice number of correction, about 7 degrees or so. They increased the PROs. They had the KT reduced from 7 to 1. And they had no residual pivot and no revisions, which I believe because I have similar experience with it. And they had some unplanned complication for hematoma. So it's a fairly good procedure. Now this is a bit more aggressive. This is from Song in AGSM. This is 18 patients with three-year follow-up. This is done for primary ACLs. But in persons that have a really high slope, 13 and higher, and in addition, not everyone has that, but in addition, this particular patient also had large anterior subluxation. Now I agree that if you see that combo, you may want to think about this. Now I, in Pittsburgh, see mainly acute ACLs. So no, even if they have a high slope, they're not anteriorly subluxed like this. But in chronics, you can maybe see that. So anyway, their slope change was corrected from 18 to 8. I think that's a very reasonable number. They had improvement in lysone-tegna-IKDC. They had the KT reduced. They also had no pivot shifts and no graft re-ruptures. So there's interesting data. So here are your options. You do closing wedge, opening wedge osteotomies. We're talking specific about the slope correction, which obviously you can do for the PCR by creating a slope, or the ACL by reducing it. These are the three different options. I, these days, choose the number one here, which is the juror described above the tubercle. I think it's technically quite demanding, so I started with the one that Sonia Ricote described through the tubercle. I think it's a bit easier to learn. And then there's also the option to go below the tubercle, which you question healing, but it's a pretty easy procedure as well. Here are the instruments that you need. So you need nice, sharp, thin osteotomes. You need laminar spreaders. Of course, you need drill bits, a saw, and then you need whatever fixation in the end you would like to use. Here are some of the plates that you can use, and make sure you look at three-dimensional anatomy. I actually like to print not just a 3D CT scan, but also a 3D print of the actual bone. It's very helpful. You know how long your screws are, how deep you cut, etc. So on this slide, I would like to show you real brief the technique of the supratubicle osteotomy. This starts by a quite generous exposure on both the MCL as well as the IT band side. You really pay to elevate everything off. Then the patella tendon must get exposed very carefully, and guide pins are placed media and lateral to the patella tendon. Then once confirmed under fluoroscopy, which you see on the lower left, you can then start with a saw and finish with osteotomes, and remove these wedges. These wedges need to be symmetric so as to avoid varus alvargus, unless you want to change that. These wedges should be as complete as possible, meaning if you leave too much of a posterior hinge, you won't be able to reduce the osteotomy. In addition, the bone that is posterior to the patella tendon, so the very anterior part of the tibia, you need to remove as well, otherwise it will not close. Now as far as hinge fractures go for this particular procedure, you can imagine that you have a very solid posterior capsule and PCL structure protecting your hinge in the back. So this is a good thing to have. But in essence, once the osteotomy wedges are removed, you can then reduce the joint by hyperextending the knee, and then you can put your fixation on either a staple or a plate, or whichever of your choosing. So here is this first case that I showed you. These are intraoperative pictures. If you start from the left, so these are four guide pins placed with the aim being the posterior insertion of the PCL, so the proximal part of the champagne glass drop-off. You see a retractor in place as well. You see that endobotan party there on the upper, on the femur with three previous reconstructions. After the wedges are removed, these are the postoperative x-rays. So this particular patient we really overcorrected purposefully to almost neutral. Now this is a patient who has a flexion contracture for at least three years or four years, so he's never had the ability to fully extend his knee. So he really enjoyed postoperatively being able to extend. If this is a patient who has previous hyperextension, then do not go there. At three months follow-up, he really had no further infection that he had on the previous procedures. He had healed incisions. He's doing quite well. His IKDC has now jumped to 57. His KT1000, without doing a revision ACL, has reduced from five to three, previously nine versus three. So the big question here is, do you even need to do a second stage and do the ACL? And that question is an open question we can discuss during the live meeting. So with this, I'd just like to invite you to an amazing symposium coming up next year in Pittsburgh, the Freddie Fu Panther Sports Medicine Symposium. We'll talk about osteotomy, complex knee, and everything else you like. I wish you a great meeting and see you soon.

Volker Muser

slope reducing high tibial osteotomy

ACL reconstruction

allografts

anterior subluxation