So I'm Andrew Gieson, I'm at the University of Vermont, and as I said, I'll be talking about the meniscal root and ramp lesions. Disclosures are on the Academy website. So recognition of concomitant injuries is certainly important in ACL patients. We can't just think of these as isolated tears. We have to scrutinize the MRI, really think carefully on the exam, and then really evaluate all structures intraoperatively. We recognize the biomechanical importance of meniscal tears and the influence on ACL reconstruction outcomes. Then we have to think about the surgical treatment options as well as how this will influence rehabilitation. We know that young patients are at elevated risk of ACL graft tear and contralateral native ACL tear, and we see a lot of different factors that can contribute to this. On the radiograph here on the right, you see a scaly, immature patient with an elevated tibial slope, and we know that increases risk of failure or laxity in your graft. A recent study in OJSM 2020 revealed almost 32% of female soccer players under 18 years that returned to sport sustained a graft tear or contralateral ACL tear. If you look at MOON data, it says maybe it's 6%, but that's looking at everyone, all ages. If you look at the young patient, we know they're at elevated risk for re-tear. Webster in 2016 reported that 28.3% of males less than 18 years old sustained a graft tear. That's a pretty high rate. And in my opinion, primary ACL reconstruction should be a pretty reproducible procedure. That doesn't mean reproducible outcome or low re-tear rate, but at least the procedure is reproducible, and I think most people in this room can walk through a primary ACL reconstruction and use their graft choice and have a good outcome, at least a good intraoperative outcome. It's where you have meniscal tears and complex meniscal tears, and I think that really influences the surgical decision-making and the rehabilitation and can have a profound impact on the outcome. And we'll specifically be talking about ramp lesions and root tears. This is a study in KSSTA looking at a large number of patients, 358 primary ACL reconstructions and a subset of revision ACL reconstructions, and 239 had meniscal tears. And what they found is there was 28% of patients with a contact injury had a medial meniscal ramp lesion and 16% of non-contacts. So think about your mechanism. We're seeing several studies coming out that show higher incidence of ramp lesion and root tears in contact-related, and 36% of all patients had either a lateral meniscal root or a medial meniscal ramp lesion. This is from the ESCA under-45 committee, so trying to look at younger surgeons, and they had 140 of the surgeons complete the survey, and they compared the results to five years prior to see any changes or trends in practice. And what they were identifying is increased incidence of ramp lesion and root tear identification, not necessarily that there was more incidence of the injury, but that surgeons were finding them more prevalent. And they also found that patients were undergoing lateral meniscal repair and ramp lesion at increased frequency, and they also found that they were doing more antilateral complex reconstructions, and we'll be talking about that today as well. Root tears are much more common in the lateral compartment compared to the medial compartment. We are seeing some root tears in the medial compartment in ACL-injured patients that have elevated BMI. Now, typically, the medial roots are in 50- to 60-year-old females, elevated BMI, perhaps. Not always, but that seems to correlate. But I've seen a handful of them in young patients that have elevated BMI. But really, what we're thinking about primarily is the lateral meniscal root tear in these ACL-injured patients. And a lot of studies have looked at this, anywhere from 10- to 16-percent higher incidence in revision ACL reconstruction, having lateral meniscal root tears. And similar to the ramp lesions, the contact mechanism seems to have increased risk for a lateral meniscal root tear. So it's really important to think about the anatomy. This is a study from 10 years ago looking at the anatomy of the lateral meniscal root and the medial meniscal root, and it looks at quantitative and qualitative findings. And it's important to look at the relationship between the roots and the ACL and the PCL tibial attachments. And the lateral meniscal posterior root is not continuous with the ACL attachment. And some surgeons and researchers have suggested that you could do your lateral meniscal root repair by just pulling the sutures down your ACL tunnel. And pretty clearly, you can see from this figure that they're a considerable distance away from each other. So pulling that through the ACL tunnel is not a good option. It really needs to have an anatomic repair. We know that there's a large biomechanical importance of the lateral meniscal root. These are contact mechanics studies looking at pressure, force, area, and location. This is a study we did seven years ago published in KSSDA. And the lateral meniscal root repair nearly normalizes contact mechanics. So it doesn't completely normalize it, but it nearly normalizes it in the setting of ACL reconstruction. And if you don't do the repair and just do the ACL reconstruction, you can find that there's still a pretty considerable increased contact pressure in the posterior compartment and posterior aspect of the plateau. Not only are contact mechanics important, but stability is important. And we know from the time zero studies that there's an important role for lateral meniscus for rotatory stability. And that's what we're focusing on with ACL reconstructions. Of course, you want to have a normal Lachman, but you also want to have a normal pivot shift test. You don't want to have an unstable knee from a rotational standpoint. And that was reported by Musal and AJSM 2010 looking at the lateral meniscus importance for rotatory stability. And we know that root repair improves stability. That's been published in several studies. And we know that there's an individual role for the lateral meniscus root near extension, the anterolateral ligament, maybe around 30 degrees, and that was published by Lording in 2017. So I think it's important to recognize that there's biomechanical importance of the root, one in terms of contact mechanics, but two in terms of the actual stability. So on examination, your patients may have a high-grade Lachman and pivot shift. You need to really scrutinize the MRI because there's a high false negative rate. And in the study by Aaron Critch in 2018, 30 of 45 were missed on the initial radiology report. So I think it's because the imaging is not necessarily optimized for identification and also we're not necessarily looking at them and scrutinizing that part of the knee. When you go in and you're doing an arthroscopy, it's important to identify the root tear prior to debridement of the ACL stump because sometimes it'll be scarred and you won't be able to see it. So putting the knee in figure four and probing it prior to doing ACL debridement is going to be important. Oscillation test was described where you put the shaver in the lateral compartment, turn on the suction but don't turn on the oscillation, and you can see the lateral meniscus moving in and out as the suction turns on. You should look at the meniscal femoral ligaments. We published a study saying that the meniscal femoral ligaments can stabilize the knee for just pure axial loading in terms of the contact mechanics. But with rotational instability, there have been more studies showing that the lateral meniscal root really has an importance there and that just intact meniscal femoral ligaments probably isn't enough. And you want to look at the native attachment. Medial root tears, as I mentioned, can also be identified and this is a patient with an elevated BMI as you can suppose from the MRI and showing a complete medial meniscal root tear on the coronal MRI. This was found at arthroscopy too and this was an adolescent with ACL with a medial root tear. So we think only lateral, you should also look at the medial root. When you're considering repair and you find these lesions, you want to identify the attachment, prepare the repair site. I like the two tunnel technique but there's certainly single tunnel techniques that are successful. Pass and shuttle the sutures and if you're using a second tunnel, you'll want to repeat the same steps and pass for the second tunnel sutures and then perform your fixation. Here you can see a probe in the left image demonstrating the unstable root tear and then the root repair on the right side. Ramp lesions, shifting gears here from root to ramp. Ramp lesions have been historically described and there's recently an increased focus. And 24% of ACL tears, increased incidence with contact mechanism have had ramp lesions on large studies that was reported in KSSDA about four years ago. There was another large study by a sonority group reported that there's almost the same incidence, 23.9%. So if you're looking for these lesions, especially in young patients, especially in contact mechanism, you're probably going to find them at a pretty high frequency. Now there's some debate on what is a ramp lesion, where is the actual tear. It's been described as opposed to your meniscal capsular junction or meniscal tibial ligament injury. But there is some controversy regarding the biomechanical role in surgical repair indications because these can heal based on the meniscal tear location and the blood flow. And there's some debate on whether or not these need to be repaired. This has been studied in the lab by several groups. One of them is by DeFilippo in 2018 and they looked at cadaveric knees and they found increased anterior tibial translation with transection of the ACL and with transection of the ramp attachment site or the meniscal tibial ligaments and increased internal rotation. So there's clearly a role in terms of anterior translation and internal rotation. And if you just did the ACL reconstruction, it restored the translation but did not restore internal rotation stability. If you fixed the ramp lesion and did the ACL, it restored the internal rotation and the anterior translation. So again, time zero biomechanical study, but it is showing that repair of the lesion does improve the stability of the knee. You can look for these on MRI and we published a study five years ago looking at 301 ACLs and 16.6% had ramp lesions. You want to look for that posterior medial tibial plateau bony edema. And it was present in 36 of 50 patients. But you have to be careful because that can also be present in posterolateral knee injuries. So if you see posterior medial bone bruising, not just your standard posterolateral with ACLs, but if you see the posterior medial, you need to look for a ramp lesion. But you also need to scrutinize your posterolateral corner of the knee, have a low threshold of doing stress x-rays in the office. Dr. Chawla will be talking a little bit more about stress x-rays in his talk on collateral ligament injuries. But only 48% of these, similar to the lateral menisca root tears, only 48% were identified by the radiologist on the pre-op MRI. So you need to be careful and identify these on your MRI and drive through the notch and identify them at the time of arthroscopy. And this video shows that driving through the notch in that patient looking at the lateral meniscal, I'm sorry, at the medial ramp lesion. And here's the still photo showing the same thing. So just viewing anteriorly, you can see the probe pulling on the unstable tear. But when you go through the notch and you can see the capsule and the meniscus and that arrow's pointing at the ramp lesion, that was very unstable in this patient. There's a lot of different techniques for repair. You can do all inside, you can do inside out, or you can use a posterior medial portal approach. I prefer the inside out repair, especially in larger, unstable tears. These are images showing each of the techniques. One is repair of a lesion on the left with all inside techniques showing that the meniscus and the capsule are reduced to each other. You can see an inside out technique in the middle, and then using a posterior medial portal with a curved suture passer on the right. So there's several different techniques that can be utilized. To my knowledge, there aren't a lot of randomized studies looking at comparison. There have been some comparison studies looking at them, but they weren't randomized to one technique or another. But there is some developing clinical evidence. The higher grade pivot shift on EUA in patients with ramp lesions was reported in 2020. When you fix the ramp lesion, compare those patients to those with an intact meniscus, there was no difference in patient-reported outcomes. So we think that repairing it helps to make them more similar to the intact patient. There have been some studies looking at improved MRI healing with all inside repair compared to no repair. So the MRI appears to be healed when you fix it. And there's also a study that said that peripheral longitudinal posterior ramp lesions, that improved healing with a suture hook compared to all inside, and they also improved with ALL reconstruction. So that's the only study that I'm familiar with that really compared those two different techniques. Again, here we're seeing ALL reconstruction, and Dr. Larson will be talking a little bit about the anterolateral complex and ALL reconstruction and indications. So in summary, it's really important to identify concomitant injuries with ACL patients. We saw that there's a very high rate of re-tear, unfortunately, especially high in the young patients, and that can be devastating to have to undergo revision ACL reconstruction. We know that time-zero studies show that the root tears and ramp lesions have biomechanical importance. More clinical data is developing, and surgical repair with anatomic principles is important for these. I think based on timing, we'll skip over a couple cases and get back to those at the end if we have time, and we'll move over to Dr. Chawla with collateral ligaments.

meniscal root lesions

ramp lesions

ACL injuries

MRI scans

intraoperative structures