Okay, we've got a lot to run through about meniscus to share with you. These are my disclosures. So, you know, how does it happen? This is my favorite running back of all time. That jump cut is hard to reproduce, right? That flexed knee and that sudden twist. And how do these injuries occur? That's usually the force. It's a closed chain type knee flexion, squatting activity, or rapid acceleration or deceleration, or meniscus tears obviously can occur with our ligamentous injuries. Important to understand, again, the load-bearing function of the meniscus. It's a gasket. Its job is to distribute the load from the femur to the tibia to turn the compressive stresses into our hoop stresses, circumferentially. The loading pattern, 50% in full extension, 85% in 90 degrees of flexion. Remember, the posterior root bears the biggest load in flexion. Fact, Cox showed this a long time ago in 1975 in an important canine study. How much meniscus tissue was removed correlated with how much degenerative change is going to develop. So if you take the meniscus out, eventually that patient's going to get arthritis. So our goal should be preserving the meniscus. So we need to talk about restoring the anatomy, function, blood supply, adjunctive measures, where do biologics fit in, stability of the knee, and post-operative protection obviously is important. Vascular anatomy, we're learning the importance of the meniscal chondrocytes, the capillary plexus as Arnowski showed. Also, don't forget about what's called the synovial fringe that can help our healing repairs. And diffusion is how the nutrition is provided to the inner aspect of the meniscus. This is Arnowski's famous slide showing the outer third, blood supply kind of in the red, red, red, white zone. And then the synovial fringe is shown here in one of my patients. This exists, and I think this also helps our healing process intrinsically. What can we do extrinsically? So we can do a notch microfracture, which is an easy way, hopefully, to maybe get some of the bone marrow stem cells into the joint. We know that, in general, that repairs with ACL reconstruction heal better, so maybe an isolated repair can be helpful. And biologics and PRP and others may have a role. This is one of my cases, lateral meniscal repair is done. It's very simple and easy to come in and make your microfracture here. In this particular case, actually, the tourniquet was up, but once the tourniquet's down, you get some good bleeding into the notch. Easy to do. What about PRP? What's in the literature? This was published in 2019, a big study out of Ohio State. Had 550 patients with and without PRP. Some had ACL reconstructions as well. Bottom line in yellow there, isolated meniscal repairs, PRP had a greater statistically significant less risk of re-tear or failure. With concomitant ACL reconstruction, though, PRP didn't matter, right? So you already have the PRP in your joint because you're drilling those bone sockets. Another meta-analysis, small number of patients in this study, only 274 patients, published a couple years ago. PRP augmentation had lower failure rates, 11% versus 20% for meniscal repair in isolated cases. But the gist of this study was they needed more higher quality studies. So PRP may help our repairs. How do you do it? What do you do? You've got different options. You can use an all-inside device, Capsuler-based. You can use a meniscal suture passing device, which I would term more of a meniscal-based repair. And don't forget our gold standard inside-out long needles, which are still in play. This was a study that I was involved with just to kind of help me determine what I use. This was published last year. And we looked at different devices for an all-inside technique, TruSpan, Fast-Fix, AIR, and FiberStitch, and compared them to passing long needles. This was our model. You can see where we have the meniscus pulling and our cyclic loading. What we found out, first of all, was all-inside was actually better in our study for fixation strength than inside-out suturing. And of the devices that we tested, the FiberStitch turned out to be the best in terms of primary internal fixation, gap formation, highest stiffness, and highest ultimate load, comparing to those other devices. These are a couple of descriptions of the meniscal suturing devices that you can do to pass all-inside sutures, where you would tie an arthroscopic knot. Do not forget, again, about the inside-out technique. Just have to know your anatomy. Posture medially, you want to avoid that infraterior branch, the saphenous nerve, and, of course, laterally, the perineal nerve comes into play. So I still do this at times, depending on the type of tear. I think it's super important to understand this concept of circumferential compression. We want to make sure that we get these meniscal repairs as stable as we can, with usually vertical mattress sutures, but always think about putting a suture underneath the meniscus, which I'll show you a bit later. What's our dilemma in football players? So suture it, they're going to be out a lot longer, right? It's going to take longer to recover. You know, if you excise it, they get back quicker, but now you've increased that risk for degenerative changes. So you know, this concept of shared decision-making with your athlete, giving them their pros and cons, you know, obviously, in some players, they decide to take it out, and it is what it is. They're going to have to deal with that later, but I think repair is always my preference and what I try to recommend to our players. So this one is a tough one in football. We all see it. This is a really bad actor, the radial tear of the lateral meniscus. Very problematic to deal with. If you take this out, they're going to get arthritic change very quickly, we find. A lot of these patients have a valgus knee to start with, and then they have this radial tear of the lateral meniscus, it's not going to go well. This has been shown in mechanical studies, Lee showed, that a radial tear is equivalent to a complete meniscectomy because you're cutting across all those hoop fibers. So you can't convert those axial loads into the hoop stresses. So this is a bad deal. I think it's really, really important when dealing with this injury to be very flexible with repair. You know, sometimes I'll use side-to-side, all-in-side, sometimes I'll pass inside-out needles. You don't have to worry about the perineal nerve at this location because you're well anterior to it, and I'll do all-inside sutures as well. So here's an example of this tear. Obviously, it's avascular, white-white, but this thing goes back almost to the capsule. You clean it up and look at it. You know, can you fix this thing? So I just start and I see what I can do. Sometimes I've done it where I put some sutures in, it doesn't look very good, I'll end up, if I have to trim it, I will. But this one came out pretty well. And actually, since it was pretty avascular, I added some PRP to that one at the end. Post-op, I think it's super important, radial tears need to be protected weight-bearing for four to six weeks. I let them move past 90. I only restrict my root repairs to 90 degrees early on, but this one, I want to get them moving right away. And I use a lateral unloader brace in my football guys once they start weight-bearing, and initially when they return to play, to protect that repair so it doesn't re-tear. Sometimes these tears, you know, are complex, and I think, again, they have to be flexible. In cases, I'll show you here, sometimes I'll do a partial mastectomy and then I'll do a repair. I'll do as much meniscus as I can, and you have to be creative. Here's an example of a, this is a high school soccer player. I didn't think I could put that flat back, totally avascular, but underneath there, there's something else going on, you'll see in a second. So this isn't that big a piece to take out, so you think, okay, everything looks good, I'll just trim that out, I'm all done. But you clean it up, and now you've got this tear. So now you've got this cleavage tear, and those can lead to meniscal cysts on the lateral side very commonly, or re-tears. So I'll do this so-called hay bale suture here. I try to avoid the papateous tendon on the lateral side, I don't really like to put sutures through that. So in this particular case, I ended up putting three sutures in, and he went on to do fine. So hopefully he didn't lose that much to where his risk of arthritis comes up. What about our medium meniscal tears now? Vertical posterior horn tear here, I think it's really important for preparation, isolated tear, so I use this little meniscal rasp, almost treat it like a non-union, I'm trying to stimulate that capsule to heal. Here's my all-in-side device, I'm going to place a vertical mattress suture here, which again I think gives us that best compression. So we put a couple of these in, as you see here, nice all-in-side device, I think these work very well, and as long as you can see, so I put a couple of those verticals in, and this is the thing underneath. I think this particular tear has to have that additional compression to heal. Posterior horn is a really stable structure to begin with, you want extra mobility there, so I come underneath the meniscus now and put my last suture underneath to get that ideal compression on top and below the meniscus. So now you see as this knot's deployed and secured, now that posterior horn lays down very nicely with those three sutures. Again, in some cases you just can't repair it, I mean this particular tear I'm going to trim, right, and it'll come back really quickly, there's no way I'm going to fix that. I think in general, and this is, you know, being an older guy in the business, I think medial mastectomies tend to do pretty well in athletes, as opposed to partial lateral mastectomies. So what about that risk of knee osteoarthritis, this was a registry study that looked at eight years in Sweden, 2,500 patients basically, and they just looked at what's the risk of developing arthritis over that time frame, and that risk after partial mastectomy, you can see here, was 17%, was only 10% after repair. So overall in this particular registry study, there was a 25 to 50% less chance that a patient presented for knee osteoarthritis if they had a meniscal repair compared to partial mastectomy. So in a longer term registry study, looking at this, repair was better than partial mastectomy. I need to touch a little bit about root tears, roots are really important and you will see them in athletes, they maintain the contact pressure across the tib-fib joint, they're the anchor point for those circumferential fibers. So if you have a root tear, you need to fix it. Total meniscal root tears are very common, more common than ACL tears, medial meniscus roots, you can see them, and I'll show you a case in a second that I recently had. A layer showed us that if you have a medial meniscus root tear, it's like a total meniscectomy in the lab, but if you repaired it, it restored function back to normal, so we need to fix these tears. Again, we just increased tibiofemoral contact pressures, altered kinematics, meniscal extrusion, which develops into later arthritis, and they're not that uncommon, 10 to 21% of all meniscus tears are roots. I have a low threshold for doing what's called a superficial MCL lengthening, or a pie crust technique. You can see this tear on the left, hard to see, after we opened it up with the needle, we didn't see the root much better. I will do this, not only root tears, but if I have a medial meniscus tear, and I can't see it well, I would much rather protect the articular surface and do a good repair than bung up the surface by putting needles in, or have my fellow bung it up with doing that. So we'll do a very superficial medial claro lengthening, and this study by Mark Miller looked at six studies where the release was done, and they found that there was minimal grade one laxity, no residual valgus and follow up. So I think it's safe to do that, and I'll even do it in an athlete if I have to. I want to protect their articular cartilage. This is a case I just had recently. This is a non-contact injury in a high school football player, medial meniscus root tear, ACL tear, and I looked on the lateral side, and his lateral root was torn. I've actually never seen this in my entire career, on a young kid, non-contact. So the question here is how do you fix everything? So I passed my channel for my lateral miscus root, I passed my sutures here, pulled that down, didn't fix it yet. I went ahead and passed my medial miscus root sutures first, then I created my ACL socket so I could not avoid convergence. Then at the end of that I drilled my socket for my medial root. So just kind of a sequential how do you handle this with multiple sockets with two roots and an ACL. So I passed those sutures, fixed his ACL, and then at the end you'll see here, look back on the lateral side. So the lateral root's repaired and secured, and then the medial root's down as well. So pretty unusual case for two root tears and an ACL on a young guy. It can happen. What about our outcomes of meniscal repair? What's in the literature? This was published a few years back, looked at 664 patients, comparable pre-injury and post-op Tegner scores. Return to play was very good in this particular study, and that was within four to six months. Pulled failure rate, and this is generally the number you'll see, about 21%. In this particular study, though, it was less in pro-athletes. This was a more recent study published last year, a big number of patients, 1612 patients. Follow-up minimum was five years. Overall failure rate was 22.6%. But the early generation all-inside devices was 30%. The later devices that we're now using was almost 16%. Notice in this study, medial tears retore more than lateral tears. And so I think that's important. All-inside versus inside-out was about the same. And they did not find a difference in ACL reconstruction versus isolated, which is unusual because other studies have shown that ACL reconstruction helps our meniscal repairs. But medial were greater than lateral. So this was a comparison that, a study that came out from Andy Williams in London, looking at elite athletes in his practice, which he takes care of most of the elite soccer players in England, and they've showed a 21% failure rate in his study. All medial meniscal repairs had an eight-time higher failure rate compared to all-inside lateral meniscus repairs. Again, medial, there's something going on with medial meniscus tears. They have a higher failure rate, and it's been shown in his study as well. And at one year, 8% lateral meniscus failed, 16% at one year failed in the medial meniscus in these high-level athletes. So keep that in mind. One other thing I want to tell you, be aggressive with lateral meniscus tears. I have several cases like this. This is what we call lateral meniscus oblique radial tear, a type four that we've categorized. Big flap of meniscus, looks awful, right? How am I going to get that back? I would just tell you, just try it, be aggressive. So I'm looking at this, and I told my fellow, yeah, I'll fix this, we'll see how it comes together. So I'm passing an all-inside device here, end up passing basically a spanning suture just to pull it over to see if I can get it over. And you'll see in a second, it's not my best work. Looks pretty junky. Fellow's going, doc, what are you doing here, bud? How's that going to work? So I want you to look at this at the end. So that's the repair, a couple of spanning sutures there too. Fixes ACL, and now look at the repair. I've seen this several times. The lateral meniscus can reduce itself, so be very aggressive and just try to fix those. It's amazing how well it can look later on when you finish your ACL surgery. So in conclusion, repair the meniscus whenever you can. I think you need to be flexible, all-inside, inside-out, with different techniques for different tears. I think the role of biologics right now is not clear, and that's microfracture is easy, so that's what I typically do with my isolated repairs. I think, again, be very aggressive, especially with lateral meniscus. I think the literature shows lateral meniscus tears heal better, number one, and from a clinical perspective, I think lateral meniscus tears that are removed, partial lateral meniscectomy, have an increased risk of OA, especially in athletes, compared to the medial side. So I think a trim in a medial meniscus is not, in my mind, quite as bad as trimming a lateral meniscus. Thank you.

meniscus injuries

tears

load-bearing function

repairing meniscus tears

aggressive repair