It's a great group together, it's a lot of fun, learning a lot from everyone. So we'll just get right into this, this is a 21-year-old college soccer player, female, had an ACL tear, and then we're looking at the lateral meniscus here on the sagittal and axial views, you can see the posterior horn, lateral meniscus, some abnormality. I'm gonna give you the coronal view here, I think that left coronal view is a very good one to focus on. And then the question is what's the diagnosis, I'm gonna give you the scope video here, and the video's totally not working, wow. It was just working in the speaker ready room 25 minutes ago. Well let's just, I guess we can discuss at your tables while we work on getting the video up, but I think this is kind of the money shot here, what's the diagnosis and how would you treat this in this college soccer player with an ACL injury? All right, we'll take five minutes, is all the faculty comfortable with what the tear pattern is? Oh, there you go, just somebody clipped it off. The point we're making is lateral meniscus root detachments are uncommon, typically it's more of a radial split adjacent to the root, this oblique tear, and as Sharon will talk to you about, the options are do you put sutures in and repair the main body down to bone like a root, or do you side to side this? Would anyone have taken this out in this soccer player with an ACL? Any of the tables, talking about taking it out? Maybe. Maybe? Yeah. We had this conversation at the table, the one thing is these actually love to heal, like sometimes if you delay your ACL reconstruction you see how these things are starting to heal on their own, like with the fibrin deposition, so I have a reasonably high level of confidence that this will probably heal if you do something to it, but sometimes you get this little pointy flap that's just sticking up in the air and sticking towards the ACL and they'll get almost missed. I've taken those out and I used to take them out for years, you know, so lots of ways to answer that question probably, like all these cases, but anyway, I do think these love to heal because you get examples when you get a delayed ACL reconstruction, you see it heal, which is pretty telling, without anything in it. So I think the group correctly identified this, this is a lateral meniscus oblique radial tear, so for me, I think it's important to go in and identify that kickstand fragment first, these often, if they're large enough, will kick up into the notch, so it's important to look for them. It's also important to recognize that they can scar into your ACL stump, this is one that's just very mildly scarred, but if you see a piece of that lateral meniscus missing, go check your ACL stump and hopefully your fellow hasn't put it in the shaver tubing already, but I think over time we probably have shaved out some of these unknowingly. So then I think, you know, it's dealer's choice. I think here you have to do some sort of all inside repair, inside out, it's just too central. I prefer this self-retrieving device just because that fragment is very mobile, so it helps control and stabilize it, it creates a very, very small perforation, and then I think by not tying instead of going through the capsule, A, it's a little bit more safe in terms of the neurovascular structures, but B, you also really maintain the normal mobility of the lateral meniscus. So occasionally when we tie two knots, and occasionally we'll over-reduce these, and that's 100% okay because if you just cycle the knee a little bit, they'll actually find a pretty significant anatomic reduction, so go drill your ACL, come back, take a look at it, and these will reduce very well. The question is, do they heal, to Brian's point, and here's an example of a second look arthroscopy in one of Mike Stewart's patients, showing good synovialization and healing. If you look in the literature, there's a series of 29 of these on second look and MRI, and they do heal very well, they do re-synovialize. So these are relatively common, about one in eight of your ACLs with a pivot shift will have them, so definitely need to look for them. We did some biomechanics work that I'll just go through very briefly, just on the effect of how it, you know, basically the meniscus is a secondary stabilizer for the ACL, and when you look, these type threes and fours, which are nearly complete or complete, they will show an increase in translation, really at all flexion angles. So what happens with treatment biomechanically, if you leave it, if you debride it, or if you repair it? Well, if you debride it, you actually increase translation about two millimeters, even with doing a well-performed ACL reconstruction, and if you take it out on your pivot shift, you lose about a millimeter and a half, and I don't know about you in the room, but I'm not a good enough ACL surgeon where I can just give up two millimeters at time zero by taking out that fragment of the meniscus. So I would encourage you, at least biomechanically, definitely repair, restore the secondary stabilizers. And then finally, I'll just show you the extrusion measurements. This is the native ACL meniscus. What's interesting, if you just create an ACL tear and you load it in the lab, you actually will see some extrusion of the lateral meniscus. When you reconstruct the ACL, it goes back in. When you create that LMART4, that full-thickness oblique radial tear, you will see extrusion. If you repair it, it goes back. And then if you take it out, that's the worst case. You get about four millimeters of extrusion at time zero. So I'd encourage you not to take these out. And then clinically, we just looked up our results of repair at an average of five years, compared that to a group without a tear, and basically saw no difference as if they didn't have a meniscus tear. So I would just say, look for them. They are very common. They do have negative effects on instability and extrusion. So our preference would be to restore them, if at all possible, in order to regain meniscus function and knee function. Any questions? Yes, sir. Yes, I have a training device. What size suture? I like these things bigger, but I worry about the... Good question for the group. I typically use 2.0 in suture, and I typically use permanent suture. Now, when you look at case studies, particularly out of Asia, they'll use absorbable suture for their meniscus repairs. But I think here we tend to use permanent suture. But I don't want to go over the 2.0. I think it's just too coarse for the meniscus. So that's what I use. Any difference in the faculty? Do they use any 0 or number 2 for this? I use that mini suture tape. That 0.9 millimeter is nice. Yeah. Good. Yes, thank you. Okay.

ACL tear

lateral meniscus

abnormalities

diagnoses

treatment options