Well, thanks, Al. It's great to be here with everybody this afternoon. So here's this ACL injury in an 18-year-old football player with this tear of the posterior horn of the lateral meniscus. And the question is, what would you do, and how would you do it? Well, what we're looking at is the lateral meniscus oblique radial tear, or the LMART. And once thought uncommon, we published in 600 Knees, this is up to one in eight ACL injuries that has a pivot shift. So why is it unique? Well, it's not a root tear. It exits more than a centimeter away from the root. It's observed only with ACL injury. We're told in the past to maybe leave it alone, maybe debride it. I think we often fail to recognize it. We didn't understand its biomechanical importance. So we started with the biomechanics, comparing knees that had these LMART tears to ones that had intact menisci with ACL injuries. And what we found was that these LMART tears increased both the anterior jaw as well as pivot shift testing for all angles tested. We then looked at the biomechanics of treatment options, including leaving it, debriding it, or repairing it. And if you take it out, what happens is you lose about two millimeters of anterior translation for your anterior drawer. And when you look at your pivot shift, it's a similar story. If you take it out or if you leave it, you lose about a millimeter and a half of pivot shift compared to restoring it with repair. But I'm not a good enough ACL surgeon to leave a millimeter and a half of pivot shift in the operating room. So how are we going to repair it? We think about our ABCs, anatomic reduction, biologic preparation, and circumferential compression. Here, I think it's important to identify what I call the kickstand fragment. So oftentimes, the fragment will flip up into the notch. So you can sometimes see that in the MRI, but it's really an arthroscopic diagnosis. A pearl is that this will often scar into your ACL stump. So sometimes, you get in the knee, and it just looks like there's a piece missing. Well, examine your ACL stump first because you don't want that ending up in your shave or tubing. When you look at the blood supply, this is an incredibly vascular area of the meniscus. It has branches of lateral inferior geniculate artery. So spend a little bit of time rasping and encourage bleeding at the repair site. When we think about fixation, I think for the lateral meniscus, it's important that we maintain the normal stability by intrameniscal fixation. When we repair it to the capsule on the lateral side, we are creating some extrusion and perhaps some stress risers through our perforations. We then consider the anatomic reduction suture first. I like some sort of self-retrieving device because this is a very small mobile fragment that you can completely control with this device. You can place a small perforation very precisely. And then with knot tying, we're really able to control the tension that we can visualize directly, which we really like in this scenario. Once you have your first reduction suture placed, then you can add multiple sutures. This is an early one. Maybe I got a little too enthusiastic about the number of sutures. But you can see it provides very good compression across the repair site. Don't be concerned if you over-compress it. This is an example of a two-suture repair where you can see a little bit of over-compression. If you do that, just cycle the knee or you can drill your ACL femoral socket and come back, and this will settle out to a nice anatomic reduction. With this technique, if you use two sutures, we're also getting circumferential compression. With traditional all-inside devices, you're choosing either the top or the bottom. Here you get 360 degrees of circumferential compression. These are often associated with other tears. Here's a complete L-mort with also a radial tear of the body. And maybe this is a meniscus in the past we didn't think was repairable. But the good news is now we have excellent techniques. This is a tie-grip repair of the radial tear of the body. And then we'll place our two sutures for complete L-mort tear. This is actually quite an efficient repair that doesn't take a lot of time and saves that compartment for that young patient. So you're asking, do they heal? Well, when you look at second look cases, yes, they do heal well. Those sutures resynovialize. When you look in the literature, 97% healing on MRI and over 90% healing on second look arthroscopy. What about clinical results? We're just publishing our five-year functional results on L-mort repair in a match group compared to an isolated ACL reconstruction. In 100 knees, we saw one ACL failure in each group and no reoperations for meniscus repair failure. So the good news for our patients is that if we do a good job on these repairs, it's similar clinical outcome as if they didn't have a lateral tear at all. So in conclusion for L-mort tears, they certainly do have negative effects on knee instability. We recommend all inside repair to restore the stability and remember our ABCs. These do have a high healing rate and excellent clinical outcome. Thank you.

knee injury

lateral meniscus tear

knee stability

treatment options

intrameniscal fixation