talks, hopefully we'll rise to the occasion here, but we'll talk about root tears, just a little bit of our journey, where we're at, and maybe where we're going. My disclosures can be found in the program. So I think we've, you know, just like all these meniscus things, nothing happens in a vacuum, and we've certainly been on a journey over the past 10 to 15 years. Particularly with roots, it was just recognizing that they actually exist, how we diagnose them in our patients, trying to define what the natural history of the untreated knee is. Certainly we've had an explosion of technique innovation, looking at results critically, widespread adoption, and, you know, where are we now? So first of all, just understand the natural history. So this was an MRI study we did of patients treated non-operatively, and you can see we looked at their cartilage grade, just on their femur. Within five months, you know, they went from kind of that grade two chondromalacia to grade three and a half, so very rapid progression in some of these knees. When you look at them clinically overall, this was our original five-year study on 52 patients, and if you looked at the conversion to total knee arthroplasty and just how they rated their knees, you saw an 87% failure rate with a lot of arthritis, and we saw worse results in females, which we feel is probably due to overload of the bone, maybe some proximal tibial osteopenia. We just updated those results. They were published in AJSM this month, and at 15 years, unfortunately, you had a better chance of being deceased than you did a successful non-operative outcome. So why not just perform a partial meniscectomy? I still get questions about this, and, you know, we looked at our clinical results, and they're very, very poor. They're actually much worse than non-operative management. You know, just removing more of what's not functioning is just not going to be a successful strategy. So I think when you see these patients in clinic, you have to understand is the meniscus tear, you know, kind of meniscus negative symptoms, meaning they're having symptoms for the meniscus not functioning. If that's the case, then removing any meniscal tissue is, in fact, going to make them worse. Sometimes you'll have meniscus positive, right, mechanical symptoms, a sharp pain with twisting where you go in and maybe take out a flap, and they're feeling better. But again, here we saw risk factors again, everything for bone overload. So females, BMI, meniscus extrusion. So should we repair any of these? Well, of course, and we really credit our colleagues, you know, in Asia, particularly in Seoul, Dr. Professor Jin-Goo Kim was really a pioneer, did a lot of early repairs, you know, starting 20 years ago. I know he spent some time at Pittsburgh as well, which really, I think, got the thought process started here in the U.S. Here's our work just on 47 prospective kind of all-comer patients. When you look at them overall, you see substantial improvement in clinical outcomes. So, you know, your IKDC improved almost four times MCID, which is great. But when you look at their MRIs, although they had a high rate of healing, we saw about 97% healing with their trans-tibial techniques, we didn't solve extrusion. Extrusion actually increased from baseline pre-operatively to six months post-operatively. And then when we just looked, we did a deeper dive just into all our root repairs that had two to five-year follow-up. You can see in these 51 repairs, the patients that did better actually had less extrusion. So if you had four millimeters or more of extrusion, you didn't do so great even with the repair. Maybe a little bit better, maybe bought a little bit more time, but just, you know, we're starting to really peel back the layers and see, you know, who really responds and doesn't. And it's these ones that have a lot of extrusion that aren't getting as good a benefit. And that's really echoed by Dr. Professor Kim's work as well. He saw that extrusion had a 1.5 times risk of total knee arthroplasty when he's repairing the roots. So sometimes you think you're at your goal, and sometimes you recognize that you're not, and there's another mountain to climb. So just backing up and talking a little bit about extrusion, Dr. Flanagan mentioned in his talks, but it's just simply meniscal displacement beyond the tibial plateau. And this is not a new concept. There's been papers published in the late 90s showing an independent predictor of both cartilage loss of subchondral bone edema. Obviously, if that meniscus is extruded, it's not biomechanically functioning. So how do we measure it? You know, some people are using dynamic ultrasound, and that certainly is, you know, a very convenient option. But, you know, when you're in clinic and you're an hour behind in your patients, it's not really feasible, I think, in all of our clinics. So really the gold standard is MRI, recognizing it is non-weight-bearing. However, we seem to have zeroed in on three millimeters as kind of being clinically significant. More than three millimeters, probably not having the ability to resist those hoop stress for the meniscus. So is it correctable? Well, I think it depends on the cause, and we can theorize and debate a little bit on why the meniscus is extruded. But this study of high tibial osteotomies, all they did is correct the varus alignment. They didn't touch the meniscus. And you can see here, at two years and four years, the extrusion improved. So clearly it was malalignment causing overload, leading to the extrusion, that once they corrected that, actually it improved. So it is reversible if you can identify a root cause. What is the primary cause of extrusion? You know, going back to anatomy, I'm just gonna talk about the medial side. It's clearly the meniscus tibial ligaments. And we look back through our MRIs, and we try to ask ourselves, in knees without arthritis that do not have a meniscus tear, you know, does extrusion exist? And it did, but a hundred percent of those cases had abnormality of the meniscus tibial ligament. So clearly the meniscus tibial ligament is a predictor of extrusion. Now again, you can think of five or six different reasons why the meniscus tibial ligament would be abnormal, whether it's increased BMI, malalignment, cartilage loss, etc. But I think we have to really pay attention to it. Why does it matter? Well, you know, we debate about condom protection, and I think we'd all prefer an intact meniscus. I think we all up here recognize that a repaired meniscus probably is not a normal biomechanical meniscus. And this study, a long-term study of meniscus transplants, showed that, you know, it was all about extrusion. So if you had less than three millimeters of extrusion, that transplant was chondroprotective, and beyond three millimeters of extrusion, although it helped clinically, radiographically, it really lost all of its benefit for chondroprotection. So the question is, you know, do we ever improve extrusion after root repair? So we had, I showed you the six-month MRI data. We went back and looked at one-week post-op data, and that's our current protocol. I get MRIs on one week and six-month time points for my root repairs, and the answer is no. Even with our techniques of release and different things, just never pulled that meniscus back in. So this got us to thinking, you know, the dogma used to be root tears cause extrusion. We all had these patients in clinic that, you know, had an injury a week ago, they got up off a couch, they felt a pop, and you get this MRI, and you get these long-standing changes. Cartilage wear, bone edema, you know, how is that possible? So we went back and looked at 63 serial MRIs in patients that were treated inoperatively, and there were some that presented with extrusion with an intact root that then developed a root tear. So really we think this is the pathology now. You know, you get failure of the meniscus tibial ligaments for a variety of reasons. That places increased stress on your root, and then these patients, you know, the degenerative roots, you know, they step off a curb, they're getting up off a low chair, they feel the pop, and that's kind of the terminal event, if you will. So they're presenting with this MRI, you know, that already shows cartilage wear, tibial edema, and that's the problem is they've been brewing in the background for a long time. This meniscus has been failing, and now we see the root tear. Put another way, I just like visual images. So, you know, this is a normal meniscus, so if you're walking on that suspension bridge, that's a bridge that can resist the hoop stress and keeps you suspended. This is one where this meniscus tibial ligament is failing. It's starting to extrude. Not sure I want to walk across that bridge for a long time, and then finally when the root fails, that's your terminal event, and that meniscus can no longer support any resistance to hoop stress, and you get increased loads. So the question is, can we, you know, change this with arthroscopic centralization, the concept being addressing the meniscus tibial ligaments, trying to bring that meniscus back in with root repair, and for, you know, I'll steal this from our shoulder colleagues. They've done an excellent job of, you know, educating us. When you look at the Bankart versus the ALPSA, so the ALPSA lesion, of course, is that displaced capsule labral tissue, and what are we taught? We have to re-tension the system. We have to release, retention, and repair. I think it's the same thing in the knee. It's just the difference is here, it's the meniscus tibial ligaments rather than the capsule labral tissue. So this is our current algorithm looking at extrusion. So you will see that patient that has a painful extruded meniscus that maybe has some intrasubstance signal, but doesn't have a root tear, doesn't have a cleavage tear. We will perform isolated arthroscopic centralization in that patient, and they actually do quite well. When they have a root tear, of course, we're addressing the root tear and centralizing if they have more than three millimeters of extrusion. And then, of course, you have to treat the malalignment. Don't undertreat the malalignment in your patients. So here's just an example. You can see our root repair, and you can see our centralization sutures. But the key is, you know, we need to change the position of that meniscus. So we're developing ways to measure this intraoperatively in terms of extrusion, but you really want to change fundamentally the position of the meniscus. So does it work? We're just publishing our biomechanics data. We presented them at ORS, and it does, when you look at it biomechanically at all flexion angles, it does take both the root repair and the centralization to restore the position of the native meniscus when it has meniscal tibial ligament deficiency. Sorry, this is just in draft form, but I think this is going to be great pictorially. So what we did is we just scribed meniscus positions with load, and, you know, we measure extrusion in the coronal plane because that's the easiest for look at an MRI. We have to remember this is a three-dimensional problem. So when you look at extrusion, the majority of it actually is post remedial. It's sagittal extrusion as well. So this outer line represents, you know, basically the extruded state with a root tear, and then you can see we restore that with the root repair and the centralization suture. So that will be published very, very soon. Clinically, we just have our clinical work accepted. So this is 25 patients, two-year follow-up. You can see these are the patients you see in clinics. So 19 of the 25 were female, 50 years of age, elevated BMI, substantial extrusion, some moderate chondromalacia, and a little bit of malalignment. When you look at how they did, their pain scores improved significantly at two years, both at rest and with use. When you look at their IKDC scores, they did substantially improve. Now you have to recognize as well, an IKDC of 70, you know, is not great. You know, these people aren't running marathons necessarily, but they're substantially better than when they come to you in clinic. When you look at Koos Jr., substantially improved, and again, you can see here a moderate activity level for these patients. When we're looking, we're just getting to our imaging. Unfortunately, COVID disrupted all of our follow-up imaging in our studies, but we'll have some analysis. But we are seeing improvements on that six-month imaging versus root repair alone. So in conclusion, I think, you know, it's important to understand the degenerative root injury includes pre-existing extrusion in a lot of patients. So we really have to take that into our treatment algorithms. Of course, root repairs can be successful in the right patient. We'll probably have some debate about who are the right patients. And, you know, we're very early on in thinking about extrusion and centralization. So I'm trying to cautiously apply it and follow it rigorously and report the science on it. But we really don't know at this point, you know, whether centralization is the answer to address the extruded meniscus. So with that, thank you very much. Very nice presentation. That's great. I'm happy to take more questions if you're all interested. Yeah, go ahead. Hi. That was an awesome talk, Dr. Kritsch. Thank you very much. You know, most of these patients that we see are between 45 and 60 years old, you know, active people, some of them more active than others. And we have the hard decision to make, you know, these people that are still busy in their lives working, to put them through an operation that's going to take them almost nine months to fully recover from. You know, what you just showed is amazing, but you're talking about potentially having to do a high-intensity osteotomy, you know, centralization, root repair. Do it. I mean. Do it. It's not that big of a deal. The reason I say this is because, I mean, I'm thinking of, I had a civil engineer that I worked on that had a great recovery, but it took him nine months. And so he told me, he said, just make sure you sit down and talk to your patients and let them know it took me nine months. So, you know, if you have someone that you have the option of doing a uni and they go back to work in six weeks, comfortable. I mean, it's a hard decision. You have to sit down with the patient and let them decide. You know, give them the options. Because really it's their life. I'm just bringing this up because it's a long recovery for a lot of these patients to go through. You talk about a right knee, they can't drive for a long time. Just something that needs to be, I think, underscored. So Aaron, where do you draw the line then? I think it's the question. Do you draw the line for uni versus the joint preservation? Where? Yeah, so first of all, I really appreciate your question and I couldn't agree with you more. You have to take a lot of time. You know, when I see this coming up on my clinical schedule, I'm like, you know, okay, this is gonna take some time to explain options. And I think you have to be fully transparent with your patients. That being said, you know, patients recover at all different rates. You know, we see ACLs recover at different rates, cartilage, et cetera. So some, you know, can do much better than that. But a lot of these patients come in, I mean, they have more severe pain, more limited physical function than the vast majority of patients that you see come to clinic. And it's been there a while. So I think it is taking some time just to recover from surgery and then recover from all the deficits that they came into clinic with. So I share your sentiments. You gotta have an informed discussion, decision-making. Now, where do we draw the line? For me, if I start to see joint space narrowing on a PA flexion view, unless they have malalignment that can be treated with an osteotomy or these different things, I think that might be the cutoff where, you know, root repair or even root repair essentialization may not be enough. And that's really, right, that's an unmet need in our patients. And that's why, you know, if you go to the exhibit hall, you'll see different options that different people are looking at very thoughtfully to treat those patients. But I'm not sure if, you know, in a 52-year-old just putting a uni in them, I mean, time will tell, I guess, but I don't know if we have the, you know, end story on that either. You know, I'm not sure if that's the best option. And honestly, if you discuss most options with patients, a lot of them do choose, you know, their native knee, but, you know, you will have some that have two advanced changes and they will choose arthroplasty. And, you know, I think ultimately the decision is there, so. Yeah, I think your comment is great. You know, the shared decision-making is absolute key. You cannot do a root repair on somebody and not really disclose to them that it's at least a six-month process. And the six weeks of crutches in patients that have these root tears hasn't really been a deal breaker in my practice because they're happy you have something for them where you know the meniscectomy is gonna lead exactly nowhere. And I think when I said to you, do it with the osteotomy, think about you're doing a root repair, so you're already going six to nine months, so you can add that osteotomy for zero cost as far as how much length it will add to their recovery. You know, of course it will have a little additional pain early on, but I would not recommend doing a root repair if there's five or more degrees of varus and not addressing it. It's not addressed to any particular member of the panel. What would you do for torn discoid lateral meniscus? And the follow-up question to that is, would you screen the other asymptomatic knee? So can you say the first question again? The torn? Torn discoid lateral meniscus. Oh, torn discoid lateral meniscus. Yeah, so you're asking would we repair it versus resect it? I think it depends a little bit exactly how and what is torn. I would probably reshape and repair. Do you have any tricks, David? Yeah, I think typically, you know, we'll see a few different type of tear patterns with those discoid menisci. You're gonna see a radial tear that may just be something you need a saucerization, that's all that they need. Or you may see a radial tear that goes all the way to the periphery. And those I would saucerize to make it look more C-shaped and then do your standard radial repair. And I think the other type of tear that we'll typically see, especially as they get older, is that they have a huge horizontal cleavage component through that discoid meniscus from degeneration over time. And then we'll have a secondary tear typically on the undersurface that almost makes it like a small flap tear underneath there. And those you'll saucerize as well, and you'll have a horizontal cleavage component and then repair the horizontal cleavage component. One tip and trick I would really, really strongly recommend when it comes to lateral, horizontal cleavage meniscus repairs. This is one that if you're gonna repair and you're gonna have to use an inside-out or outside-in technique, the sutures definitely need to be underneath the IT band. You cannot have those sutures on the IT band. Well, actually, and you cannot over-tighten the sutures. You'll actually extrude the meniscus if you do that, and you will lead to rapid chondrolysis still on that outside. And this is, again, from learning experience in my early years of doing these type of repairs. So you really need to make sure that those sutures are tied underneath the IT band against the capsule. Mm-hmm. Yeah, I would just agree with everything that was said. We looked at our 25-year follow-up on our local discoid patients, and we have to discuss with those families, to the gentleman's point here, is whatever operation you do on that discoid meniscus is not your last operation. They can go 10 years with interval-free surgery, but if you repair it, it probably will re-tear again at some point. If you remove a little bit, they probably will end up with a meniscus transplant. They probably will end up with an osteotomy. So if you follow these patients out long enough, these are really bad actors. So I think we, as surgeons, need to do whatever we can at each stage to save as much meniscus as possible. Excellent. Another question? Question about your indications for osteotomy combined with a root repair. Five degrees is a relatively small number, and you see a lot of different tibial morphology. Sometimes you have those people who just have that varus-looking tibia versus are they varus? Are you comparing it to the contralateral knee or just looking at the knee in isolation? Because most times they have symmetrical anatomy. I can tell you for myself, and I'd like to hear, of course, everybody's opinion on this. If the weight-bearing axis goes through the compartment that has the meniscus root lesion, I have a short trigger to go after it. If you're saying that somebody has a bilateral five-degree varus, you may not want to address that. People are trying to look for numbers, and I have a failed root of a meniscus transplant with a two-degree varus, but so I gave basically the biologic adjunct of osteotomy to that root repair. So every case is a little bit different. I think if your weight-bearing line goes through the ipsilateral compartment, you're asking for trouble not addressing this. You at least need to discuss it. What do you think, David? Yeah, so I'm gonna maybe give a little bit of a different opinion. I've really struggled with talking about osteotomies, similar to some of the comments from our people in this room, with someone who's 60 who has a root. I really struggle with that. I just don't know if that morbidity is the right answer. Looking at a lot of our roots, and we're still getting this data, we have not seen a difference in our failure rates for malalignment. Now that might change as we continue to get the rest of our data. I think the biggest argument I have is if they're still young. I still would say I'm young, so I'm in my early 50s, and or below that, I would definitely consider the osteotomy, but I do struggle in some of our older patients of saying you need an osteotomy and a meniscal root. It's just my opinion. Yeah, there's some good data out of Seoul, Repressor Kim's work, that he looked at patients that had between five and 10 degrees of varus malalignment, and they still had significant benefit with isolated root repair alone, but you have to remember, those are patients with BMIs of 23 on average. So if you have a patient with a BMI of 33 that has six degrees of varus, I just don't know if they're gonna benefit from root repair alone. Andy, anything different for you? No, I mean, I think that I was struck, Aaron, by your compelling argument for why centralization is such an exciting thing on the frontiers, because I wonder as you continue to elucidate the biomechanical and clinical implications of this, if the success of our root repair has improved and maybe starts shrinking the indications for the osteotomy. And so I'm excited to see where that goes. Another question, please. For the root repairs, rehab protocol in terms of weight bearing, and are you bracing them? And then a follow-up is, does anybody have an absolute BMI contraindication to doing a root repair? Very nice. Aaron. So for me, I do brace them. A, because I'm releasing the MCL. So, I mean, they really have to be braced, I think. For me, I go toe touch for four weeks, and then weeks five and six, I do let them start weight bearing. I just think six weeks complete, you know, non-weight bearing, I just think it's really hard. They start getting wrist issues, shoulder issues, you know, all kinds of issues. And then my motion, I limit to 90 degrees for the first four weeks, but after that, I let them do motion as tolerated. I think we've just all seen some stiffness, and I think at four weeks, it's probably okay. So a couple things we learned with some of our series. One, we used to never brace people, and this is before we released MCLs. And we found that a lot of this generation in 50s through 60s would get extremely stiff and lose their extension. So I think the brace for our protocol has been really utilized to help gain their extension right away, but we use it for a very short time so that they don't get too stiff with their flexion. The other thing that we realized in our series, we used to never do DVT prophylaxis outside of just an aspirin a day. We had higher incidence of significant blood clots with these patients, and so now they all get Eloquist for their weight-bearing restricted time and then go to aspirin, and their DVT risk has gone down dramatically. So things to consider in this patient population as well. BMI. I wanted to answer the BMI question. Andy, do you have a high BMI threshold in Texas? You better not. Yeah, no, I mean, I think that the nature of my patient population, I mean, we're not talking about root tears typically, the medial meniscus root tears in active duty people, but I still take care of a fair amount of beneficiaries and things like that. So, I mean, I think that if we get north of 35, 40, I start thinking pretty hard about it, and maybe start- 35? 40. 40? That's it? I have no BMI restriction, and here's my reasoning for this. Obviously, they're gonna have a higher rate of failure. There's no other option for these patients, right? So they're gonna be at such a high risk of rapid chondrolysis, and if you can save it, and even if only 75% of those are successful, which is a lot lower than a lot of these other roots, you've done 75% of those patients a benefit. Yeah. So, I mean, I wanna give credit to Chris Harner for coming up with the idea of root repair. We did the same fellowship, Aaron and I, just a few years removed, and in my fellowship, we were cutting out every single root, and they're asking me, so in Pittsburgh, you really repair roots? I'm like, yeah, I don't know if it's gonna work. So coming out of fellowship, I really didn't do root for a long time, because I just didn't think it's a good idea, and then we all learned it actually worked. They're large people. They already have some wear and tear. I mean, if the joint space is gone, you can't really go there, but some wear and tear in the joint, they're all, I mean, they're very few failures. It's a powerful procedure. Anyway.

meniscus root tears

treatment options

diagnosing

meniscectomy

centralization techniques

extrusion