All right, let's go ahead and get started. Good afternoon, everybody. My name is Sam Dixit. I'm at HSS in New York City, and I have the privilege of moderating this session on knee ligament injuries and dislocations with Dr. Christopher Hogriff at the University of Iowa. This is a National Fellow Online Lecture Series. It's been sponsored by the AMSSM Online Fellows Education Subcommittee. It's sort of a combination of education and fellowship committees that have been supporting us, and we thank them for their support. The goals of this lecture series are to serve as an adjunct to your individual program's educational programming, provide fellows with direct access to educational experiences with experienced AMSSM members, and at times, invited guests in a variety of formats, and assist in CAQ preparation. We ask that you mute your device's microphone and turn off your video. Any questions you have, please submit via the chat function. Include your name and the program if you wish, and I will collate those questions and ask them at the end, based on the time we have in a question and answer session. And after the program, please do complete the evaluation, which will be sent at the end of the lecture. So Dr. Hogriff is a Clinical Associate Professor at the University of Iowa. He's also a team physician with the Chicago Cubs. His background is in emergency medicine, and he has a CAQ in sports medicine, and I've had a chance to review his slides. They're great. So you guys are getting a real treat. So I will stop sharing and turn it over to him. Well, thank you, Dr. Dixit. I think you've set a bar that I may have a hard time meeting, but I will try not to at least trip on that bar. It is a genuine honor to be invited by the subcommittee. Dr. Dixit, hopefully you can see that slide okay. Looks good. Perfect. All right. So again, an honor and a privilege to be invited by the AMS SM Education Subcommittee. Happy to chat with everyone. Without further ado, we'll get started. Before we go any further, I am compensated by the Chicago Cubs for my work with them, but as it pertains to this presentation, I have no financial disclosures or conflicts of interest. A couple of objectives, just to go over briefly, we're going to talk about the epidemiology of all three conditions, ligamentous injuries, patellar dislocations, and knee dislocations. I think it's important to highlight some of the risk factors associated with those injuries. We'll also cover some physical exam tools, many of which you know, but a couple of them perhaps you do not, or at least appreciate the significance of the findings of those exam techniques. We will review some imaging things. We're not going to delve into the nuances of MRIs and their role in managing these conditions, but there are some plain film considerations that I think warrant a bit of discussion. We will talk about the treatment nuances for these injuries and the disposition for the patients. And hopefully throughout the course of the next 50 plus minutes or so, you will be entertained on some level. Every time I give a presentation, I like to include what I call edutainment at bare minimum breaks up the monotony of having to hear me drone on and on about academic matters. So we'll break that up a little bit with some knee buckling edutainment. Anytime I can poke fun at the White Sox, I try to do so. All right, we'll play a little game. Interactive. Play it hard. We'll play name, last, at name. Looks like a devastating name. All right. I'll show a picture. Name the athlete. Name is running back from the University of Miami, Willis McGahee. And here's how he suffered his devastating knee injury. And I believe it was the Fiesta Bowl. So probably doesn't take the completion of fellowship to realize that he had a problem. This is a more recent case. Give you a moment to ponder. All right. This is McKenzie Milton from the University of Central Florida. And just a couple of years ago, he's rolling out right on the boot and gets hit. And it doesn't look so bad because there are people in the way. But notice the angle positioning of his right lower leg. Clearly not normal. You can generally tell by the reaction of the other players how significant an injury is by how many have been recoil in the process. All right. Some anatomy things just to set the stage. I think it's an important foundation before we continue. We're going to highlight the four main structural components of the knee. You guys are all well aware of this. ACL, PCL, MCL, and LCL. A couple of things to keep in mind. While it happens, it's relatively uncommon for these things to be injured in isolation with a significant injury. In particular, the ACL, more than half of the time, is accompanied by a lateral meniscal tear. I don't agree with any of the facts and figures discussed here. It depends on the study, quality of the study, et cetera. I tried to give a representation of the most common percentages and likelihoods of things. So a little latitude there would be appreciated. With regard to the PCL, always keep in mind that the posterior lateral corner, the composition of structures between the back outer corner of the knee involving the meniscus and the IT band that form that structural support. These injuries can disrupt that posterior lateral corner as well. With regard to ACLs, this number fluctuates wildly depending on what you read, but it's thought to be about 200,000 ACL injuries annually in the U.S. with about half of those being ruptures and half of them being reconstructed on an annual basis. This is thought to be up to 50% of all knee injuries, so probably the most common significant knee injury. Shown is Lamar Houston celebrating his sack and ending it with a complete tear of his ACL. So remember humility, kids, humility. The PCL, the incidence of this is really quite obscure in the literature. There are thoughts that 2% of them are asymptomatic. I did a physical examination on a pitcher this year who had a complete tear of his PCL that was totally asymptomatic and had been going on for quite some time. Stress exam can reveal maybe three to four times as many of these, and perhaps up to 20% of injuries to the knee are thought to involve the PCL. Again, hard to pin down, but that's what the best literature can provide at the moment. And because I am emergency medicine trained and see scores of knee injuries in that context as well, perhaps up to a quarter of those knee-related visits involve the MCL and LCL. Now, this is a mixed bag. It's not necessarily the MCL or the LCL in isolation, but a common occurrence. But with that said, isolated LCL injuries are fairly rare, and this is described in multiple different literature sources. Less than 2% of all knee injuries involve an aciated LCL. So if you do find an LCL injury, you should start hunting for the other structure that is damaged in accordance with it. Risk factors, and I think many of you know these things, but we'll cover them. So females have shown to be at significantly higher risk for ACL ruptures than males, and there's lots of varying theories on why that could be the case, whether it's cue angles, hormonally related, muscular control, et cetera. Not entirely clear, but we do know that it's a significantly higher risk for women. Interestingly, particularly when you look at soccer, for women, they tend to injure the stance leg or that plant leg more often than men who injure the kicking leg. It does happen statistically earlier in females than it does in males, and with regard to specific sport, more common in women in soccer and men in basketball, and I think that's controlled for rate of involvement. PCL risk factors, gender doesn't seem to play as big a risk here. Dashboard mechanism is common. That's obviously not going to be the case in sports per se, outside of perhaps NASCAR, but if you think about how that happens with the anterior force directing the tibia posteriorly, you can see how the PCL would be compromised. Hyper-extension is also a common way that you can injure it. That's Ronald Acuna Jr. running down the first baseline. He didn't actually tear his PCL, but I think it's a good representation of what hyper-extension in the knee can look like. Our next famous athlete. This one's a little more obscure, perhaps. However, it was a big deal. I believe it occurred on Monday Night Football, if I remember correctly. And this is Napoleon McComb. So he's running into the line against the 49ers, and I believe it's Ken Norton Jr. wraps him up here and rolls him over with his foot underneath him, and you can tell that the knee doesn't bend that way. All right. On to the physical exam. Anytime you can put jazzercise in a presentation, I think you're well on your way. Let's review some of the pertinent physical exam maneuvers for evaluating the ligamentous structures of the knee. And I think everybody has heard of the interior drawer, right? Again, sensitivity and specificity vary, but a fair representation is 55% sensitive and 92% specific. A lot of the time, any of these knees maneuvers are studied. It's done under anesthesia, so you lose some of the confounding factors, which means the pure test is studied under those contexts. But in the practical world, when we're evaluating these athletes on the court, on the sideline, in the clinic or emergency department, it may not hold quite the same. So take it with a grain of salt, please. With regard to the interior drawer sign, be very aware of the posterior sag. So if they have translation of the tibia posteriorly at baseline, that tibia will translate forward a fair amount and give you the feeling that it's lax, when in all actuality, you're pulling it back to neutral first, and there may not be any interior translation further. So consider that when you're doing this maneuver. The other thing to keep in mind, and part of the reason why this can be limited, particularly in the acute injury, right, if you're assessing an offensive lineman, it can be hard to get the knee in that position or simply move it just given the general size. And also, like anything in fluid, if there's an effusion present, things will slide a little bit, and it can be hard to determine if there's a firm endpoint. So keep all those things in mind, along with the caveat that sometimes patients won't be able to or won't flex their knee to allow for this positioning, and it may limit this test. And if that's the case, then you have to look elsewhere to try to identify an ACL injury. Moving on to lockman's test, another one you are all probably quite familiar with, right? Higher sensitivity and roughly the same specificity. Video showing there. Notice that I like to slightly externally rotate the leg prior to doing so. And oftentimes, if you want to add a little bit of kind of bounce to the leg, just a light bounce, that'll kind of trick the patient. They won't know when you're going to start to translate. And oftentimes, if you want to add a little bit of kind of bounce to the leg, just a light bounce, that'll kind of trick the patient. They won't know when you're going to start to translate the tibia against the femur, and it may allow them to relax more. Helpful trick along the way. What you're feeling for is an abrupt halt versus that kind of soft, elastic feeling. And you've probably done many of these, and that abrupt halt, patients will even feel that. And when you don't feel that, that's a striking difference, particularly the first time you note it. But keep in mind, at the end of the day, this doesn't necessarily account for partial tears. It can be difficult to pick up on those. And again, laxity in the setting of an infusion can be a difficult thing to pick up and may result in a false positive. Now, in the event that the leg in question is too big or too difficult to maneuver, and you have access to a table or another elevated surface, the drop leg lockings test can be useful. So you see the provider there put the affected leg in between his thighs and translate the tibia forward while pushing down on the femur. And this can help you, rather than try to move the whole leg, can give you a little bit of a leverage advantage in identifying a potential ACL tear. And lastly, and this is one that many medical students, residents, and fellows may be not as familiar with, is the lever sign. And if you have the patient lay supine with the knee fully extended, and you place that non-threatening fist underneath their calf by pushing down on their distal femur just above the patella, and look for rise of the heel, ideally you have the heel flat on the table and the heel would lift up off the table. Since the ACL is really the only thing engaged at that point that can pick it up, if the heel does not lift, then an ACL tear is present. Obviously, you want to make sure that there's no other structural damage as well that could obscure or complicate the test. But it's a good test, and it's been shown, again, data is primarily driven out of the operating room under anesthesia, but there are some emergency department studies that validate this as just as, if not more sensitive than anterior duror and Lachman's test. And given the fact that you don't really have to manipulate the leg and worry about significant girth or an effusion, this might be a useful tool to have in your back pocket as you assess for the ACL tear. Now, I think I went through all of fellowship, and subsequently, without performing the pivot shift test, I know it's well described, I know lots of people like it, and in my case, I skip it. It's really hard to get the patient to relax. What you're essentially trying to do is recreate the mechanism that caused the injury, and patients are acutely aware of how they got injured in most cases and know what that feels like and don't care to go through it again. And quite frankly, if it's positive, it hurts like the dickens. And so I actually steer clear of this one, and that's the reason why I included a video of it being done in the operating room, because the patient's under anesthesia or has a block and can't feel it. So it does have sensitivity and specificity that makes it useful. I just find it painful and would argue that there are other ways to make the diagnosis without this test. As for the PCL, the posterior drawer is a great test. Sensitivity and specificity are very high across numerous different literature sources, and it's really the same as the anterior drawer, just in the reverse direction. So posterior translation of the leg, and look for SAG or translation. Speaking of SAG, you want to make sure that you take a peek before you do the exam, because if the tibia is already sitting posteriorly, more than 10 millimeters in most cases, pretty good indication that the PCL is not doing its job or is insufficient at that point. While you're doing it, and in another way to assess the PCL is you should consider the dial test. Now, this will give you good information on the PCL as well as the posterior lateral corner. You want to do this both at 30 degrees and 90 degrees, a flexion at the knee with the patient's supine, and you're looking for more than 10 degrees of rotation of the injured leg versus the non-injured leg. If you only see this at 30 degrees, the PCL is injured. If they have it at both 30 and 90 degrees, you should have higher concern for a posterior lateral corner injury. Now, the PCL can be involved in that as well, and often that is the case, but you want to give consideration to that posterior lateral corner as well, makes that injury a little more significant. In terms of the medial lateral collateral ligaments, the varus and valgus stress tests are plenty helpful in this regard. From a varus stress test perspective, the patient lays supine and you push on the medial side of the leg and direct that force laterally to try to get the lateral or outside portion of the knee to open up. Then the converse is the case. As shown in the video, this is a valgus stress test, patient supine, you're pushing medially with your hand on the outside. Try to get that to open up or cause pain, either one or both. I like to do this at both 30 and 90 degrees. You can see that in the video. The reason for that is at 90 degrees, a patient can lock their quad and try to stabilize their knee that way. If you get laxity at that point in time, it's generally a more significant injury. At 30 degrees, you're kind of taking that out of play and you may pick up more laxity than you would at 90 degrees for the reasons cited. Now you can read everything under the sun about this and there are studies that say that the varus and valgus stress tests are 25% sensitive. Some have cited up to 86% sensitive. I don't know what the real number is and I don't think that you can take it as gospel. It's clearly not a perfect test and there are some factors that play into its variability, but it is a good test that should be performed when there's concern for medial collateral ligament injury. Specificity, I can't find that anywhere. I never have been able to in preparation for this presentation. I went back and looked at it again. No one really reports on specificity. You have to take that with a grain of salt. If it was found in an obscure reference that I missed, I apologize, but I don't know that I would take that as gospel either. Next up in the Name That Athlete game, recently retired if I recall correctly, the Golden State Warrior in question is Sean Livingston. Sean Livingston was playing for the Clips, makes the steal, heads down the lane, is up for the layup, and lands awkwardly at best as he comes down on his left lower knee. I apologize for the graininess of the videos in some instances. It's the best quality I could find, but he suffered a complete dislocation of his knee as well. All right, so now we've covered the physical exam. Let's touch on a couple of plain film findings. I didn't think it was particularly high yield for this setting to go over the nuances of MRI findings in the context of ligamentous injuries of the knee. They're often override by radiologists, looked at in consultation with our orthopedic surgery colleagues. But oftentimes, we're left to interpret the plain films of the knee alone or before somebody else overreads them and make clinical decisions that way. So, I think that lends credence to the objectives today. So, I'm going to show you a picture of a plain film of a knee. And you let me know what's abnormal, right? In this context, it's lateral views of the knee, right? And you look carefully, you see a whole bunch of fluid, particularly in the superior patellar space. And there's a large joint diffusion there, right? Pathognomonic for ACL tear or other ligamentous injury? No, but it should give you suspicion that something else is going on there, particularly in the setting of an acute injury, OK? So, that's what you're looking for in terms of a joint diffusion. This one is more subtle, OK? So, if you look carefully, part of the reason I like to go over this is because we often look at x-rays of the knees and look for obvious fractures, and don't see them and move right along. However, there are subtle important things that we should be aware of that guide our management decision-making process moving forward. In this case, the subtle finding is right there. You can see a cortical disruption of the tibial spine, and there's an avulsion injury there. On physical examination, this patient is going to have what appears to be an ACL tear. When in all actuality, it is most likely the case that the ACL is actually intact, and that fracture is providing laxity that mimics an ACL tear. Now, I make a pretty convincing argument, I think, that if you were to pick between an ACL tear and a tibial spine avulsion, you'd much rather have the tibial spine avulsion, because if it's non-displaced like this one, then you can immobilize the knee, as in any other fracture, allow it to heal. And while there may be some secondary laxity, it should be largely intact, and the knee should function just as it did prior to injury. This is more common in adolescents, but it does happen in adults. I've seen many adults who have had this injury. So, if it's displaced, they can obviously surgically correct that with a screw, but it will give the impression of an ACL tear, but slightly different. Classic board fodder here, right, you get the plain films, and you spot that abnormality along the lateral aspect of the tibial plateau, and that is called a Sagan fracture. More than 90% of the time, this is pathognomonic for an ACL tear, okay? Now, there are other structures that can be injured with this particular finding as well. Give you a moment to consider what those might be. And if you think about what runs through that area, okay? Now, if you look at that fracture fragment carefully, it misses the joint space. So the lateral meniscus is not likely to be involved. It's always possible, but it's not likely to be involved given where this particular fragment is. We have to worry about LCL and or IT band injuries as well. They're passing through and or attaching right at that area. So make sure you assess for those as well. And in this case, right? So there is a thing called a reverse Saigon fracture as well, far less common, but described in the literature, you can get a fracture of the medial aspect of the tibial plateau by the same rotational mechanism, which again is highly suggestive of an ACL injury. And we jump from a reverse Saigon fracture to something that looks like it could be, but if you study the medial and lateral tibial plateaus carefully along the lateral side, you'll note that the plateau and proximal tibia look to be intact, but you do see a cortical disruption there. And that appears to be coming from the fibular head. When you see that kind of a Volgen injury from the fibular head, that's called an arcuate fracture. And that arcuate fracture is also highly associated with an ACL tear, right? So subtle, and that's something that'll always jump out and grab you. And when you see it, you might think, oh, that's an isolated fibular head fracture, but you need to pay particularly close attention to the ACL to make sure it's intact. You're staring at those lateral views of the knee after an acute injury. You may have noticed this subtle little divot in the distal femur. So that deep lateral sulcus sign. And that's usually an impaction, and also, again, associated with ACL pathology. It's not pathognomonic, but you need to have high suspicion for that if you see the subtle finding on lateral films of the knee. And we'll move along. These are a couple of plain films of the knee that I'll be honest, I don't always consider getting, but having re-reviewed the literature, I think they're worth considering, right? So if you look carefully, the image on the left looks like it lines up appropriately, but when you compare it to the unaffected side, the one circled shows a bit of translation posteriorly. What's happening here is those arrows are noting posterior force applied to the proximal tibia, and these are called lateral stress views. And when you see that translation, which is different from one side compared to the other, you should be highly concerned for a PCL injury as well. There are several sources that cite this as a very reliable way to diagnose PCL injury as if the posterior drawer test wasn't sensitive or specific enough, but if there's any doubt, this can be a helpful tool in confirming the diagnosis. I think you all can see that little wispy calcification noted on the medial aspect of the distal femur. And that wispy lesion is called a steatia fracture, right? And it's suggestive of an MCL injury. It's not pathognomonic again, but seeing it there, you should be concerned that perhaps the proximal attachment is no longer attached or functioning the way it should be. Over time, and this one is different, you can see that it's larger and the edges are more rounded and smooth, suggesting this perhaps is more of a chronic injury. If a steatia fracture becomes chronic, they refer to it as a Pellegrini steatia lesion, right? And that again is suggestive of an MCL injury, one that is probably longer term in nature. As we come down the imaging home stretch here, you can also put various stress on the knee during plain films. In doing so, you may see that lateral component open up. If you do see this, it's suggestive of an LCL injury. Again, remember, that's not often in isolation, so you'll have concern for other injuries as well. But another way to confirm whether or not the laxity present is contributing to the patient's symptoms. Our next guest on Name That Athlete, running back from the New England Patriots, his injury was quite noteworthy. This is Robert Edwards. He participated in that NFL sand flag football fiasco and his leg just floating up in the air at that 45 degree angle. You might imagine this was the only year, to my knowledge, that they conducted this event as Mr. Edwards suffered a knee dislocation and never successfully returned to his previous level of participation in the NFL. Okay, in general, ligamentous injuries, right? We're just talking about ligamentous injuries We're just talking about ligament injuries, not dislocations at the moment. Try to minimize complete immobilization. There's a plethora of evidence to suggest that complete immobilization can impact recovery, especially in the operative sense. It causes muscle atrophy and can affect neuromuscular control, which can delay recovery post-operatively. So you certainly want to protect the injury and you want to modify activities and you want to guard the weight bearing, but completely immobilizing the knee is not often in the best interest of the patient in a ligamentous injury. For ACL reconstructions, our first inclination is to think that these all need to be reconstructed and that actually isn't the case, right? It's an elective surgery and young active people, those involved in planting and pivoting activities are likely to get them repaired, but it's not an absolute necessity. And there are people who are engaged in lots of significant activities who are ACL deficient. So you at least have to have that conversation with patients. Now there is some variable long-term risk of osteoarthritis and meniscal damage without an ACL. That's particularly the case if you continue to engage in those planting or pivoting activities that will cause your knee to shift. But again, it's not an absolute indication for surgery. With regard to the PCL, the reconstruction here is far less common, right? It's usually in the setting of several other ligaments that are injured as well. Now, if there's an avulsion, a bony avulsion present, those are more likely to require surgery. And anyone who's chronically unstable secondary to a PCL tear, they're more likely to end up in the operating room as well. But overall, it's safe to say that PCL surgery is far less common, even in a complete tear. In terms of treatment, I advocate for this readily and sometimes it upsets orthopedic surgeons, but in reviewing the data, it's pretty clear that aspirating a knee, particularly in a setting of acute trauma where a hemarthrosis is suspected is quite beneficial to patients. It's been studied multiple times. The argument against this is that it increases the risk of infection, but the risk of infection, even the most conservative estimate is somewhere in the neighborhood of one in 3,500. And if you really wanted to be particular about it, you could distill the data and say that the risk of infection secondary to a knee aspiration is probably closer to one in 10,000. Again, debatable, but it's certainly no more risky than one in 3,500. And there are clear benefits to this too. So it's been studied in the knee in particular, and it decreases pain for seven days after aspiration. Now, of course, there will be some reaccumulation of the blood, but you improve pain and you improve range of motion by doing this. And I think it's in the patient's best interest to at least offer it. If they decline, that's perfectly fine, but it is beneficial. And don't be afraid to throw the ultrasound probe on there, particularly in a knee whose body habits make it difficult. Now, if the effusion is significant enough, you shouldn't have a hard time gaining access to the pocket of blood, but you can always use the ultrasound probe to help guide yourself into the space as well. I advocate for the superior lateral approach. Cadaver studies have verified that this is the most accurate approach. 90% of the time you'll end up in the intra-articular joint space in the knee. According to cadaver studies, the rest of the access point, whether it's medial or lateral, anteriorly, somewhere in the 60s to 70% accuracy rate. So if you can do it, try to aim superior lateral. A couple more management thoughts. From MCL perspective, surgery is not always needed either. Multiple ligaments, an avulsion fracture, or if the MCL is entrapped. Those are reasons why the patient may end up in surgery. It's usually the multiligament one that ends up there. It's fairly uncommon to have isolated MCL surgery. You've probably seen a football game or two where every lineman on both sides of the ball on both teams is wearing a brace such as the one shown in the picture. And those have actually been shown to decrease the risk of MCL injury, and that's why they wear them. So that can help in a preventative sense. LCL reconstruction is uncommon partially because it's not needed and partially because it's not common. The reasons to have the LCL reconstruction would be chronic varicose instability, which is pretty rare. And then it may get reconstructed if a posterior lateral corner injury is present. That's not always a hard and fast rule. But in general, the big treatment point here for MCL and LCL injuries is functional rehab. So even if they have surgery, and even if you're talking about ACL and PCL, preoperative rehab is super helpful in trying to maximize their preoperative range of motion, neuromuscular control, and set them up to succeed postoperatively as well. Next up on the athlete list, running back from South Carolina, was a Heisman Trophy candidate. Until this happened, this is Marcus Lattimore. So against Tennessee, he cuts to his left. You see him plant at just the wrong time, get hit on that plant leg, and you'll see his leg flop over. He has no control over it right there. Unfortunately for Mr. Lattimore, while he was drafted by the 49ers, he was never actually able to make it onto the field as a member of the 49ers. Terms of coming back from these injuries, ACL reconstruction return is highly debatable. Previously, it thought that it would take over nine months, but now it's functionally based, which seems to make sense. You have to be able to do numerous things. In the physical therapy gym, these are things like single and double leg hopping and jumping activities. Obviously, you have to be able to cut and plant without pain at full speed before somebody will let you back onto a football field or a basketball court. Classically, the thought is 12 months before a full return activity. That's variable per athlete. We've seen Adrian Peterson come back in what seemed like a matter of days. Now, the faster you come back, perhaps there's an increased likelihood that there's laxity in the ACL ligament that has been reconstructed. But again, that mileage may vary depending on the athlete. You do need to consider psychological factors. So one of the biggest things, particularly in football, is taking that first hit after you've been injured in this manner. And so addressing those concerns and making sure the athlete is completely comfortable before sending them back out into activity is critical because it could only, it could potentially set them up for a different injury or re-injury, okay? In terms of PCL, again, remember, not often surgically repaired or reconstructed. So for grade one and two PCL injuries, rehabilitation with a typical two to four week return, again, mileage may vary. In terms of three, there's relative immobilization here trying to get it to scar in and gain back the stability. And the rehab component of this will focus primarily on quad strengthening. With regard to the collateral ligaments, right? MCL timeline is based on degree. So we'll belabor the degrees too much, but I do think they're worth mentioning, right? So if they have, if the athlete has pain with no significant laxity, you can expect a return in one to two weeks. But if they have pain with laxity, although you do note an endpoint, you can look at two to four weeks. It's probably a little closer to the four week mark, but two to four weeks is what's often cited in literature. And if they don't have an endpoint, four to eight weeks is common. Again, that doesn't necessitate a surgery per se, but it does have to scar back in and allow for the medial stability of the knee. In terms of the LCL, again, there's not a robust amount of literature that discusses this, but the most commonly reported return timeframe is somewhere in the neighborhood of six to eight weeks. There are sources, including some from the USA Ski Team that say that some patients take up to three months and may have stiffness with these injuries for up to six months. I think that's variable, obviously, but a general guideline to consider both as you're managing your teams, but also as you counsel patients in the clinic and the training room. But as has been mentioned a couple of times before, as soon as you are able to start physical therapy, it's gonna set them up to succeed in the long run. It may decrease the time that they are required to miss as they progress. And I need to emphasize this one more time, proceed with caution with complete immobilization. It may be needed for a period of time, say there's a complete PCL tear, for instance, but just providing stability while allowing for range of motion of the knee, if you protect their weight-bearing status is usually sufficient and complete immobilization can cause atrophy. I have lost track of the number of patients I've seen in consultation from the emergency department who were directly diagnosed with an MCL injury, for instance, and partially perhaps because of the limited types of splints and braces that are available in an emergency department. But I've seen patients who have been sent to me in a knee immobilizer because of an MCL injury. And by the time they see me, say three weeks later, for whatever reason, their MCL has scarred and stabilized and it's no longer causing pain or laxity, but their lack of utilization of the quad in particular has caused atrophy and they don't have any neuromuscular control or as much neuromuscular control of the knee as they need. And that by itself requires physical therapy. So use caution when putting what is affectionately known as the hotdog bun in some emergency departments on the knee. Next up, tennis star. All right, this is Bethany Maddox-Sands. So during Wimbledon, she went down and they don't zoom in, but she's clearly in a ton of pain. And you can look carefully, she's holding her patella as a bit laterally, okay? So not a complete knee dislocation. This is a patellar dislocation. So let's chat about those for a second. I think anytime you can reference Peter Griffin, you're off to a good start too. All right, patellar dislocations in general. Sometimes they're non-contact. We'll see some examples of that. Other times you can be struck. Oftentimes it's a needle blow. The patella can dislocate immediately, but most of the time, the vast majority in fact, it's a lateral dislocation. These account for two to 3% of all knee injuries, at least according to epidemiologic data. It's not thought to affect one gender more than another. Classically, it occurs in the second to third decades of life, but there are several sources that say it's the most common knee injury in children. Now, I couldn't find numbers to validate this, and it was more of a statement in passing in several different references or resources. So that's why I put the question mark there. But somewhere in the neighborhood of 15% to 60%, and oftentimes it's said 50% of the time, recurrence will happen. So if it happens once, there's a fairly good chance that it can happen again. There are certain risk factors, risky business as it were, that contribute at baseline to patella dislocations. I've listed them here. Keep in mind, there may be an underlying kind of connective tissue disorder, such as Ehlers-Danlos, that can contribute to this. A high-riding patella in general can also be a cause. If the patella groove or notch is flattened, otherwise known as trochlea dysplasia, you can be predisposed to a dislocation of the patella. Having dysplastic musculature, so an insufficient vastus medialis, or overactivity of the vastus lateralis, for instance, can contribute to patella dislocations as well. So you may only be able to pick this up in hindsight, but if you're doing pre-participation physical examinations or evaluating patients who are saying they have anterior knee pain, you may look at these things and consider their risk of patellar dislocation. On the note of patellar dislocation, famous NBA player played alongside Kobe straight from high school. This is Andrew Bynum. So he had a fairly innocuous appearing injury. He just goes up for a rebound, and all of a sudden he plants his leg, and it completely gives out on him. Now, he had a career riddled with knee injuries, and in this instance, this certainly didn't help, but you'll see he lands on someone's foot, he creates that valgus moment, and he dislocated his patella in this instance. The exam's pretty straightforward for patella dislocation, right? If the patella is out of place, probably dislocated, most often laterally, as we discussed earlier. You wanna make sure you evaluate for hemarthrosis. This will often be present. Many, many, many clinic patients that I've seen have had patella dislocations, have come in days later, and still have a significant hemarthrosis. Look for tenderness along the medial patella, femoral ligament, excuse me, which is helping to hold the patella in place along with a couple other questions, muscular components, okay? Physical exam, try the apprehension test. So as the patient is lying supine with the knee extended, try to take that patella and force it laterally. The patient may note pain, they may tense up their quadriceps in an attempt to prevent you from moving that patella. That's a positive apprehension test and suggestive of likelihood or previous dislocation or subluxation of the patella. You can also look for a J sign. So this patient is showing it to us. As he extends his knee, you can see it slide. It's being held into place. So it's subluxing at this point and trying to dislocate with enough force and it may not require much that patella can slide right out of place. The other thing you wanna make sure is in the setting of a patella dislocation, make sure that the neurovascular structures are intact, far less likely to injure those structures than with a true knee dislocation, but you wanna make sure that you have evaluated those and documented them accordingly. I don't know that too many folks out there in AMSSM land or YouTube world are gonna know this one. It's a little tricky, but this is Ryder Jones. So Ryder Jones, just taking a swing, watch his face. Hello. Yeah, he just completely buckles and no one really knows why. In this case, it was because his patella dislocated and that's what gave out. And no significant history of this happening repeatedly in the past. In terms of imaging, couple of pearls for patella dislocation imaging, okay? Should you image the patella before you reduce it, after you reduce it, or both? For the most part, barring a significant trauma. So you can get post-reduction films. I think it's safe to put the patella back into place and then look for your fracture otherwise. If there's a significant mechanism of injury, so struck at a high rate of speed, for me at times in the emergency department, if it was a motor vehicle incident, those types of things, then I might get imaging beforehand. But typically post-reduction is sufficient. Give you one caveat to this though, particularly post-reduction. If you look carefully at these films, which are from an athlete that I took care of, you look carefully and these films are unremarkable. But if you get the sunrise or merchant view, skyline view, right? You can see that the patient clearly has a patella fracture. It was not seen on the AP or lateral views. Take home point here, make sure you get that additional third view. I always like to tell the residents and fellows, the knee has three compartments, medial, lateral, and the interior. You should get three views of the knee at least, AP, lateral, and merchant or skyline. The other thing you might see on plain floor The other thing you might see on plain films, particularly the merchant view or skyline view or sunrise view that I just mentioned, right? You may see this trochlear dysplasia. There's not really much of a notch there and it's flattening out the undersurface of the patella as well, but that's clearly going to predispose someone to a patellar subluxation. Next up on our hit list, that's Baron Davis. So you'll see Baron Davis bearing down on the rim here. He's headed right for a bucket and all of a sudden his knee just collapses on him when he plants and you can see a big divot there. His knee went laterally. He put his hand right in the divot. So again, non-contact patellar dislocation. LeBron, not impressed. All right, so it's out. How do you relocate it? Well, that's pretty straightforward. Just do what this young gal did. You want to roll over and you want to hit it really hard multiple times and it'll probably just go in close fist. That usually works best. All right, I'm kidding, I'm kidding, don't do that. All right, do what Patrick Mahomes did last year when he dislocated his patella. So he heads up the middle for a QB sneak and he just gets piled on and he's clearly in pain and it later came out that he dislocated his patella, but you can see what happens here is they just straighten it out and there's a clunk all of a sudden, and it hooks off the field, okay? So really patellar dislocations are that easy, right? So put pressure on the patella toward the midline. Most of the time, that's going to be a medially directed force. Straighten out the knee and the vast majority of the time, voila, back into place. And then you can straighten it out and go from there. Sometimes, occasionally the patient will need medications to make them more relaxed, et cetera. I think that's the exception rather than the rule, these usually go into place pretty, pretty easily. Okay, as I said earlier, I think post-reduction plain films are a solid plan. Okay, at that point in time, barring any fracture, you want to protect the knee. Now sometimes this requires a knee immobilizer to keep it in place, particularly if that's all that you have available to you. A Shields brace or a J brace, depending on where you're practicing, is useful as well. Now that typically has a padded component within the brace that goes laterally on the patella that helps to keep it shifting out. Obviously, if it was a medial dislocation, you'll need to reverse the orientation of that brace, but works pretty well and is functional unlike the knee immobilizer. Okay, just like Patrick Mahomes walked off the field, you can let them wait there as tolerated, you want to protect that, make sure they don't do anything that could cause subsequent dislocation of the patella. NSAIDs for pain control is needed if necessary. And then again, you may also want to consider, as was previously mentioned, aspirate the knee, particularly if it's tense. There can be a significant hemarthrosis associated with this and drawing out the blood is not necessarily a bad thing. In fact, it can be quite helpful. I've taken more than 100 milliliters of blood out of patients' knees following such injuries. You can imagine how much tension that places on the knee and minimizes range of motion. Also keep in mind, studies have shown blood is generally toxic to cartilage, so letting it sit in there is probably not doing a ton of favors to the intra-articular surface of the knee. I like to bring things full circle. Remember, we mentioned our One Direction buddy, Niall Heron, on the loose? Well, I didn't just do that because he had the song on the loose. He's actually suffered from patellar dislocations bilaterally. He had surgery on one, I believe he had surgery on the other. I couldn't independently verify that, but he suffered from patellar dislocations over the course of time. One surgery, I believe, was on his left knee, and that was about 2014, give or take, so he's afflicted as well. Overall, look for the patellar dislocation patients, right? You can pretty much guarantee physical therapy is on the way, and they're going to work on strengthening the quad, hip, and core. Careful, close to change, short exercises of the quad will generally be implemented, and can help to really stabilize it and keep it in place, okay? Many will need patellar bracing, not always for the rest of their life, but it's often the case that it'll be needed for some period of time, and again, that J brace or Shields brace is usually pretty effective in that regard. The return activity, for Patrick Mahomes, it wasn't six weeks. That's commonly cited as the length of time to rehab and keep that ECAP tracking appropriately before turning it loose to planting and pivoting activities. That, again, mileage may vary, but that's the current guideline recommendation that I could find best cited. Keep in mind, 15 to 50 percent will dislocate again in two to five years, and if that first dislocation happened before the age of 20, it's highly, highly likely that it could happen again, okay? From a surgery perspective, if there's an associated loose body or a fracture where this keeps happening repeatedly, then concern for reconstruction of the medial patellofemoral ligament or different other surgeries that we won't get into that improve alignment may need to be considered. And even our friend shown right here, who surprisingly my wife did not get, so this is McDonald's newest spokesperson, Travis Scott, and while at a

3rd Edition, CASE 30

3rd Edition

Knee

knee ligament injuries

dislocations

AMSSM Online Fellows Educational Series

ACL

PCL

MCL

LCL

diagnostic tests

functional rehabilitation

imaging considerations