Our next speaker is Dr. Liza Arendt from the University of Minnesota, I'm from Michigan, and she's going to be speaking on patellofemoral and meniscus disorders. Oh my gosh, the only thing worse is what I'd say if I'd been from Wisconsin or Iowa. Jeez. Okay, so sorry that this is so long, but at least we review a couple of different things. My topics are patellofemoral and meniscus. Of course, I'm a big patellofemoral geek. These are my disclosures. We're going to go through anatomy, biomechanicals, exam, and imaging. There are a few changes on your handout, I'll point them out, not too many. They use patellofemoral pain syndrome ad nauseum. We're trying very hard to stop it, but you're going to see that on questions, but it really is synonymous with anterior knee pain. We're trying to get away from the word syndrome because there's nothing syndromic about a lot of things around the patellofemoral joint. Malalignment is another word that creeps into our literature despite the fact that it's ill-defined, and we're trying to look at malalignment and maltracking as it relates to increased load, which can create pain, or increased load, which can create chondrosis or both. Patellofemoral instability, and I've actually not touched too much on arthritis because as Dave Flanagan already pointed out, AOSSM does not really treat arthritis per se with patellofemoral arthroplasty, et cetera. We'll go through some of the tendinopathies as well. Let's just get to the anatomy and biomechanics. The classic understanding of anatomy and biomechanics is that in early flexion, it's soft tissue restraints that can be both active, i.e. the muscles, and passive, which are the patellofemoral ligaments. Then once you get into deeper flexion, again, typically 30 degrees, it's the bony alignment, which is a congruity of your patella and your articular surface. As you can appreciate, that if you look at trochlea dysplasia as measured on a true lateral x-ray, the control shows that the intercondylar notch would be going here and not crossing this anterior surface, and then in dysplasia, it actually crosses the anterior surface. But I think the important thing to notice here is look at how long this trochlea is, and look at how deep it is, and look at how short the trochlea is, and you probably have to get down here, which is about 65 degrees of flexion, before you enjoy about three to five millimeters of depth, which you have right here in early flexion. So I think that although these are the classic answers, I think it depends on the length of the patella tendon, because in patella alter, you'll enter the groove later, and it depends on the length of the trochlear groove, which you can find shallowed or shortened or both in trochlea dysplasia. Again, I think the spectrum of trochlear disease is quite broad. Here you see a very short trochlea, but once you get in it, it's pretty deep. Here you see a pretty deep trochlea, but it has a big super trochlear bump. And so just be aware that there's a spectrum. We now are going to measuring trochlear depth on slice imaging, typically MRI, and this is just one analysis. This tells you it's a ratio of the addition of the medial and lateral trochlea to the central trochlea, and three millimeters right down here, less than three millimeters is defined as trochlea dysplasia. This is taken at the slice where there's a first full cartilage coverage. It has its problems, but that's the standard in the literature. The depth is typically about eight millimeters, and less than three millimeters is trochlea dysplasia. This is related. Trochlea dysplasia has a high lateral trochlear facet and medial facet hypoplasia. And so here you see that typical situation. What I think is a little bit hard to understand is that what happens in trochlea dysplasia is that the central area moves up. So this is the central trochlea, which is defined as the mid-portion of the distance across the trochlea, and that pushes the sulcus, which is the lowest point, medial. So it looks like you have this really broad and higher lateral facet compared to the medial side. The lateral and central are higher, and the medial is lower. So the static restraints are by far the one that they'll talk about is medial patellofemoral ligament. Just wanted to point out that there's lots of others that we're looking at. Here's the MPFL, medial patello-meniscal ligament, medial patello-tibial ligament. Doubt if these will be mentioned. These are just to include in your review. The consistent question that comes up again and again is what is the main stabilizing force against lateral patello translation, and the answer is medial patellofemoral ligament. It resists 60% of lateral translation, and it's greatest, of course, in extension or in early flexion, again, where that soft tissue alignment is important. The patella tendon has, these are just estimates of the length and width. Broad tendon, as you can probably appreciate, is becoming more and more used for ACL, primary and revision. In this country, mostly revisions, and the thing to know about that is it's two times the thickness of the patella tendon. Some of the other patella issues in terms of biomechanics is that the patella is there to increase the moment arm of the patella. The terminal 15 degrees of active extension is where the patella becomes most needed for that, and that's why when you have a lag, you can't get that last sort of terminal extension because your quad is weak. It's also important to recognize that the nose or the lower one-third approximately is devoid of articular cartilage, but this, of course, is extremely variable. You can see these two examples. The nose here is almost half the distance. This is quite long. That's why I put it up there, and this may be more understandable. The VMO is always talked about, although not everybody has it exactly as oblique ligaments or an oblique attachment, and it typically is attached at about a 70-degree angle. The angles are less oblique when it's patellofemoral, so they're not quite as oblique, and they're also quite a bit higher in patellofemoral disease. This is an anatomy specimen that, look at how far the fibers come down. They come all the way down to almost the mid-portion of the patella. Here we're lifting that up, and here you can see the MPFL. This would be considered a very distal extension of the VMO, although in most people, there is some covering of the MPFL by the VMO fibers. The patella has the arterial supply, it's the geniculate arteries. One point that might come up, the functional blood supply is distal to proximal and medial to lateral. That is why some people prefer that you have a lateral incision, because it saves that skin over the tibial tubercle. The patella engages in early flexion, 20 to 30 degrees, and when you get into deep flexion, the patella is no longer engaged in the groove. Now you have the quad tendon. So sometimes they ask you questions about, we'll get to a couple of these, like what's articulating with what. One question asked, what's articulating in full extension? Well, in full extension, you don't, you may have the tip of the patella, it may or may not have a cartilage on it. So where they're asking the question really depends on what degree of flexion that you are, the question is being asked. So the contact area moves approximately, and the surface area increases, so that as you, again, the patella contact area starts low on the patella and moves approximately in flexion, and it's, as you move proximal, the patella becomes wider, so that the contact area is wider, and therefore the load is dispersed. So where we have the greatest load is approximately 45 degrees of flexion, and that's where the patella typically, in a normal patella, normal patella height, it is the highest. And again, the pressure is highest in that 60 to 90 degrees of knee flexion. This is just a little bit of a cartoon to try to show you that. So here, you kind of see you're using the entire proximal to, or distal to proximal aspect of the patella. But in patella alta, what happens is that you don't have that contact area in the first 60 degrees of flexion, so you can increase the load, and possibly, therefore, the chondrosis in the proximal patella tendon and in the distal patella cartilage surface. And again, you lose that protection of the trochlear walls, and that's why patella alta is so associated with patella instability, because it takes longer for that patella to ultimately find its true home and its true stability, which are the bony walls of the trochlea. And again, just in a cartoon form, here you can see that it takes a much longer time for the patella to reach the depth of the trochlea, where it's quite more contained in regards to stability. You do know that patellofemoral joint stress is a product of joint reaction forces and contacts, and therefore, if you're thinking that stress may relate to cartilage wear and pain, the idea is to try to increase that contact. And you can do that by reducing the patella height when you have patella alta, and possibly by reducing tilt as well, because both engage more of the patella in that early flexion range. Here is just some general numbers about patella joint reaction force. As you probably can appreciate, you don't see much patellofemoral forces with walking. Stair climbing is a big one. Squatting is a big one. You may have already recognized that. But also, contracting your quad in a flex knee position, just isometrically, puts a fair amount of joint reaction force on it. So you can kind of think if you're doing an open chain activity with a load on your ankles, such as in a leg extension, they can have quite high patella joint forces. So let's just look at this. Which of the following statements concerning the biomechanics of the extensor tendon is true? So if we look at these answers, if you can just, I know the ones in your folder are pretty small. Patella increases the lever arm of the quadricep muscle. At 90 degrees, the distal end of the patella is in contact with the femur. Again, they're trying to get you to say what's in contact during what degree of flexion. The force in the patella tendon at 90 degrees is 30% greater than the force in the quad muscle. Quad tendon injuries occur during concentric contraction, and at 20 degrees of flexion, forces in the quadricep and patella tendon are equal. So this is a lot of busy answers. But certainly, the statement that's true is that it increases the lever arm of the quadricep muscle. The other ones, especially with the degrees of flexion, they're relating the wrong part of the patella with the wrong part of the femur in flexion. Which of the following is a primary strain? If they're going to give a patella femoral question, this is going to be it. And we won't spend too much time on this because the answer is the MPFL. In a normal knee, the patella becomes centralized in the trochlea by, again, this one, somewhere between 20 and 30. This one says that it's centralized because it becomes centralized first, so I would pick the one that is between 20 and 30. So 40 is definitely too deep. But if they, so I would pick B, and that was the answer that they picked as well. So you can see that some say by 30 degrees, some say by 20 degrees, but it's so dependent on the length of the patella tendon. Central quadricep tendon, again, if you're looking at what it is compared to the patella tendon, we want to just emphasize that the quad tendon is quite a bit thicker than the patella tendon, and therefore it's being used as a graft. And that may come up because it's becoming more commonplace in this country and certainly is commonplace in Europe where they have less availability of autografts, of allografts. When we're going to the patella femoral joint, we look at some static observations. These are the ones we typically look at. C-Wango we can't necessarily see by static observation, but I think that we also need to look a little bit at sort of this varus valgus and version. I just wanted to show you this series of slides and looking at this double legs partial squat. So we do know that we have the dynamic valgus in the frontal plane, but here in the sagittal plane, you can see that there's no use of the squat mechanics or the gluteal muscles, and sort of normal, you want to have that hamstring firing and you want to have that sort of good squat mechanics. And this is a very common problem with people with patella femoral pain, and if you have this anterior excursion, it really increases your chances of anterior knee pain. And we all know about the functional valgus knee, which is very common with ACL injuries, but also terribly common with patella femoral as well. So we know that you should have hips level, you know, the knees over the toes and control that knee position in sagittal and frontal plane. We also can talk a little bit about recurvatum, atrophy, some of the things that we look for in physical exam. But when it comes to the patella, the J sign, some people call it J tracking. I think J sign is being sort of centered on in the literature, and it means that you have a lateral translation and extension, and then as you go from extension to flexion, it sort of jumps into the groove. This is, some people also call this dislocation in extension, but I think the J sign is more common in the literature. You can look for crepitus, you can look for an extensional lag. Again, an extensional lag is not a soft tissue contracture, it is the difference between passive and active range of motion. Actively you cannot get to full extension because you don't have the strength. Tubal sulcus angle has been in the literature for a really long time. It isn't used so much, but it's becoming more used because if you believe that you should be doing a medialization of the tibial tubercle, you should not move it greater than a tubal sulcus angle of zero. Some people call this a sitting Q angle. So you can appreciate that if you have a Q angle, I'm sorry, if you have a TTTG that's measuring quite high, let's say 24 millimeters, if you try to move that 10 or 15 millimeters, you might be medializing the tibial tubercle, which leads to increased forces not only in the medial patella femoral joint, but also medial patella tibial joint. So this is a quick measurement in the operating room that you can use that you want to pick up that tibial tubercle, move it to directly under the patella at 90 degrees, and the tubercle sulcus angle should be zero at 90 degrees of flexion. Physical exam, remember the hip. The reason to say this is because sometimes I try to kind of fool you in regards to having a hip question that relates to the knee. IT band can be tested with OBRA test. A really easy sort of poor man's test for potential antiversion is if internal rotation is significantly greater than external rotation. And that's kind of a poor man's test for antiversion. Another one that's in the pediatric literature is internal rotation greater than 90, regardless of what external rotation is. And of course, FAI you need to think about as you think about hip pathology. The lateral translation or patella glide test has become the standard of how you look for patella mobility with the knee in extension. And again, there's some controversy as to where you measure this. But in knee in extension and passive patella translation, it's abnormal if it's greater than three millimeters. It doesn't mean they've had a dislocation. It could mean that they're hyperlaxed. And a dislocation really has to be greater than the other side associated with the appropriate history of an acute injury. The lateral patella tilt test seems to always come up, but I've never really seen it in a question. You push down the medial side of the patella, again in full extension, keeping the patella in the groove. And this lateral border should be elevated greater than the level of the horizon. This is going to come up, and we'll see it in a question, if you want to talk about the potential for a lateral retinacular release. I like to do lengthening, but they're going to say it's going to be a release and when to do it. And we'll show that in a question. I just wanted to put this in. This isn't going to come up on the test, but I thought we're also here to educate you. I also use standing alignment views to give you a quick suggestion of limb version. You can't say whether it's in the femur or tibia. I will say that there's one typo here, and I'll show you what it is. But this is the same person, same day, image taking with the toes forward. And you can see that you have hidden lesser trochanters. You can't see the lesser trochs, or you can see them right there. You have your knees. You can see that they're terribly rotated, and your ankles look pretty good. Same day, five minutes later, I asked them to put the knees forward, and you can see that your lesser trochers, now you can see. So you have visible lesser trochs, but in your handout it says hidden. So sorry about that. And you can see that your knees are now aligned, and your ankles are now rotated. So for me, especially in a person that's not having arthritis, I don't see a lot of applications for the PA view, but I do see a lot of applications for this long leg view when you're looking for knee symptoms, particularly anterior knee pain. Imaging of the patellofemoral joint in the axial view, there's many ways to do it. We'll talk a little bit about that. Loren's and Merchant's views are both commonly used in this country for flexion. The important thing is that it's got to be low flexion. Loren's is typically taken at 20 degrees of flexion. And they have various schemes about measuring patella tilt, translation of the patella. And you have to use Loren's measurements on Loren's views and Merchant's measurements on Merchant's views. And your handouts have these measurements. Merchant's views, this is the classic Merchant view. It was taken at 45 degrees of flexion, but the beam is 30 degrees from the horizon. And now in this country, it's more 30, 60 degrees used as time has marched on. And again, various schemes about how to use it. I think this Merchant's views is a little bit harder to make the measurements, but oftentimes it's a visual measurement too. But I think it's interesting to look at false negatives. This is the same view. And this is where that low flexion angle plus how your radiology technicians take the image. This is at 30 degrees of flexion, and this one is taken at 45. So you can see that when you take it at a higher degree of knee flexion, you get that deeper part of the sulcus. And you're missing what we're trying to get in an axial view, which is that proximal trochlea. So one easy way to think about this is that if you have a good axial view, you should have a longer lateral patellofacet than medial patellofacet. And if it's about 50-50, it's probably too high. So it's just kind of a nice quick view. You can also measure it on slice imaging, either CT or MRI. Certainly the instability risk factor that we've all grown up with was taken on CT scans, which is a 20-degree measurement for increased lateral tilt. The TTTG value is typically taken on CT, but obviously MRI has taken that over. You can measure the deepest portion of the sulcus to the first, the midpoint of the patella tendon at the first slice that you see it insert into bone. And again, in the CT scan, it's greater than 20 millimeters. In the MRI, it's slightly lower. 15 millimeters has been used as normal, although nobody has said what the threshold for reducing it is. So again, why are there problems? MRI measures smaller values than CT. It's not a ratio. So is it bigger and bigger patients? Some studies show yes. It does change with age. It may vary with tibial rotation. And these are some more recent methods, TT-PCL, and maybe some angular measurements. TT-PCL has some legs. Angular measurements, there's been five or six in the literature, and they've never gotten any kind of legs. They're too complicated to really use, in my opinion. And the other thing you can look in sagittal plane is patella alta and patella baja. So the problem with these sagittal plane measurements is that they're tibial based. The thing to know, incel salvati is the one that is most used in this country. I think canton de chance is more applicable for the patella femoral world. And this is the important thing to know, that if you do a distalization of the tibial tubercle, so you're correcting patella alta, you do not change the IS ratio. So this often comes up on a test. Because you're measuring the length of the patella to the length of the patella tendon, that does not change. What you change is relationship of the patella to the tibial plateau. So canton de chance may be more applicable or possibly blackborn peel. So why do two measurements matter? Because you're never going to get away with one measurement. So if you do patella femoral, you've got to use more than one measurement. Here is the same person. One shows normal. One shows quite abnormal. And it's because it's got such a big nose. Here's blackborn peel, which takes a ratio according to the tibial plateau. And that the length of the distal cartilage surface to the tibial plateau is the canton de chance. For whatever reasons, this is most popular in joint arthroplasty, but certainly can be used in any of your measurement schemes. The new kid on the block is looking at a femoral-based lesion. The Bedert is the first one to, Rolly Bedert, to introduce this. And he took the length of the articular surface of the patella to the length of the articular surface of the trochlea. Typically you do it in mid-sagical sections, so when you're seeing your cruciates. And it's a functional engagement. How much does the femur and the tibia relate to one another? This would be something that you're seeing on MRI. Now he defined Rolly Bedert as less than 0.125, which is about one-eighth, which isn't very much. But if you're trying to say, like, what is normal, normal is somewhere between one-third to one-half. And this just shows you one of the earlier control measurements that was done by Charles, but that was a Don Fithian study. But it is a very nice measurement to use. The problem with it is that if your patella is way off yonder, and you don't see the patella and the trochlea on the same image, it may be harder to use. What I like to use is just a poor man's test, is this empty sulcus sign. It's qualitative, not quantitative. But at the first cartilage slice, if you look up and all you see is the patella tendon, this is a alta patella. So again, this is a really quick and easy thing to use in your clinic. Again, CT scan or MRI, greater than 20 degrees is considered the threshold, and that's probably going to be the threshold measurement that's on a test. But recognize that MRI measurements are smaller, and not because you're measuring, I mean, they don't become smaller on the MRI. I think we're just seeing things with more clarity, and we probably get a little higher view of where the tibial tubercle inserts. And we're also taking the low point of the cartilage now, and not the bone. Nonetheless, it's about 15 degrees. It's about a 5 millimeter difference. Let's go to some questions. A 12-year-old football player sustained a sudden onset of right knee pain while blocking. Unable to continue playing, but was able to walk. Knee radiographs were normal, treated with non-NSAIDs, vaguely localizes the pain to the medial and anterior border of his knee. Physical exam, full passive range of motion, no effusion, ligaments are stable, gait demonstrates an antalgic limp, and here rolling of the hip pain. His pain is reproduced by log rolling. Log rolling that you think about hip, and this wants you to think about hip, and the answer is AP pelvis, and this was his exam. So typically, they're going to throw in one example of hip. They're going to try to give you something related to the knee. I'll also go back. The other thing is 12 years old. So you should think of SCIFI when you're seeing a young person that had right knee pain, didn't have a specific injury that created it. Knee exam was pretty normal. So kind of go with that hip. Okay. The, again, anterior knee pain, a bunch of predisposing factors, examined the entire lower limb. I will say that if there's any question on anterior knee pain, the answer is non-operative management. We have a variety of non-operative managements, not too dissimilar from what Dave just talked about with non-operative management of a lot of knee conditions, including osteoarthritis. And again, no confirmed benefit from steroid or viscose supplementation. I will say that there's no firm evidence in osteoarthritis, but there is even less convincing evidence that in the absence of chondral wear, that any of these have any applicability for anterior knee pain. Operative treatment is often similar to meniscus, that if you have a symptomatic loose body or chondral flap, I think that people can push the limits a little bit because they're seeing something on MRI that they really don't have any physical exam corollary to. But people that have effusion and catching may benefit symptomatically, but certainly long-term there's no change in what's happening to that patellofemoral joint. Again this patellofemoral malalignment, tilt and subluxation, important to know that this is not due to knee swelling. If you have an x-ray that has a knee effusion, you can't start to look at a tibial tilt. I mean, I'm sorry, patella tilt is anything that can help you identify it. Nice study by Marie Askenberger. She actually showed that if you get an ACL, she had 100 patients that were under the age of 14 that had an acute hemarthrosis. And a lot of them were ACLs, some were PCLs, et cetera, and a cohort were patellofemoral. The only ones that showed increased lateral tilt were the ones that were in MPFL were lateral patellofemoral dislocation, meaning that they had torn their medial structures. So a lot of times in our world, even me who does a lot of patellofemoral, I always thought that lateral tilt can be associated with any effusion, but you really don't see significant lateral tilt unless you have that disruption or laxity of that MPFL. So again, identify risk factors, exhaust nonoperative management. I think it's important to look at bone edema on MRI. Just like in the tibial femoral joint, that means load. And that may have more significance for saying it's early chondrosis. And if you have that bone edema laterally, it may respond to McConnell taping that can be used as an adjunct to reduce pain and to increase strength, which both lead to improvement. So again, you see this word syndrome, but this lateral patellofemoral compression syndrome or LPCS was actually identified by Ficke and Hungerford on plain MRI, I mean, I'm sorry, on plain x-rays before MRIs were popular. And they looked at this increase in subchondrosclerosis and they associated it with a tight retinaculum and increased patella tilt. It presents its pain with bent knee activities. You can have pain with lateral facet tenderness. I don't find this so useful because anterior knee pain tends to be all over, but you do, but this is important. You have a fixed lateral tilt or inability to avert the lateral edge of the patella. You can't bring that lateral edge to the level of the horizon. Again, nonoperative management and the operative treatment would be unload, and this is where a lateral release may come up as a question. You can release or lengthen it. In my world, I like to lengthen it. And you can think about an anteriorization when you have an elevated TTTG and no tightness laterally. But it's not a one-to-one that you should go to an AMZ or what some people call a focus in operation. So isolated lateral release is only in the setting of excessive lateral patella facet pressure. So that is associated with physical exam of a fixed tilt and tight retinaculum, tilt without subluxation, and lateral facet chondrosis. The important thing is to maintain the vastus lateralis fibers. Do not go into the vastus lateralis, which was certainly part of the early treatment of lateral retinacular release as defined by Metcalf early on. And certainly the risk of hemarthrosis, oftentimes the geniculate artery is difficult to, superior lateral geniculate artery is difficult to coagulate, and you have to remember to do that. Because you get a big hemarthrosis and pain, quad weakness, and then iatrogenic medial patella instability. This is just a picture of lateral lengthening, I threw that in just for your edification. Which of the following preoperative factors is conducive to achieving the most consistent and predictable results when performing an isolated lateral release? So again, you're looking at a Q angle, you're looking at hypermobility, so this is a lot of translation, a hypermobile patella, passive lateral tilt greater than 10 degrees, less than 5 degrees. So the answer is this one. So we want tightness in terms of translation medially, so you don't want hypermobility and you want to have the absence of that tilt. And then again, this is the main complication that's in the literature, although it doesn't happen very often. When it does, it's terribly disabling. It's best corrected by, and there's a bunch of answers, but the answer is to reconstruct it. This V-Yplasty, I don't have an actual question about this, but if you bend the knee and the patella is out in flexion, which is an extremely rare thing, but dislocation and flexion, that speaks to a short extensor mechanism. So that V-Yplasty, that's what improves that, is that you have to lengthen the extensor mechanism. So that comes up as an answer, although I've never, ever, ever seen dislocation and flexion as a question on a assessment exam. When we're talking about you moving the tibial tubercle, just a little bit of history. The McKay procedure was to treat pain. The Elmsley-Triot, which is anteriorization, the Elmsley-Triot procedure, which is a medialization only, was to treat instability. And then along came Fulkerson's classic work, published first in 1983, that by his own words was for persistent patellofemoral pain associated with patella articular degeneration. So the important thing is that it is used for arthritis. And what it unloads best is inferior and lateral. And so that's what you're going to see as a question. So you do the anteriorization when you have lateral facet arthrosis. It unloads distal lateral patella. So here you have this question, what does it unload? And again, distal lateral. And acute patella dislocations oftentimes associated with chondral damage. The acute dislocation is always associated with MPFL tear and it's a significant amount. So studies are varying, but it's close to 100%. So MPFL is injured. It's most often injured by the patella. And in adults it's more often associated with femoral lesions, but it still is more patella in both adults and children. And the first, if no osteochondral fragment, it's non-operative treatment. If you do have an osteochondral fragment, you can operate and they do want you to fix it. The number of patella instability factors in high demand athlete are trending towards doing this, but for answers on these kinds of tests, you got to do non-operative treatment unless you have a loose body. So if you have an ORAF, you can repair the MPFL. There is some literature support that it works. Only if you considered that you have a lesion that's off the femur or the patella, but most often people will either take it out or fix it alone or reconstruct it. If you reconstruct it in the same setting, you risk stiffness. So again, ORAF, if you can, you can repair the MPFL. Only if you have a single lesion, you can reconstruct it. The risk is postoperative stiffness. We know about the patella instability factors. These were the classically owned factors. The most common ones in many, many publications are patella alta and trochodysplasia. These are what we see in people who dislocate the patella. What's important is even though we can characterize it, we have patella alta, we have trochodysplasia, we sometimes have tilt, we sometimes have high TTTG. We at this moment in time do not know what we have to correct and at what threshold. So that is still evolving. Eighteen-year-old female sustains an acute patella dislocation. It reduces. She's unable to continue playing. Which of the following risk factors predisposes her to recurrent patella dislocations? Normal Q angle, big VMO, varus deformity of the knee, dysplasia of the femoral trochlea. Again they're looking for dysplasia of that femoral trochlea because that is the most prominent risk factor in regards to anatomic risk factors. Eighteen-year-old male soccer player required a reduction on the sidelines during the final game of the season. How would you counsel this athlete regarding treatment options? E-STEM level one supports the use of a brace, which is not true. Nonoperative treatment is preferred over surgery. The best predictor of redislocation is apprehension. That's not been true. That's been found to be true. So they're going again after this nonoperative management. I don't think this is the best question, but again, as Dave often pointed out in his last lecture, try to go with that conservative element. Tennis-ariable twister knee has a dislocation that requires closed reduction. Her post-reduction film is shown. Here you're seeing a fragment. What they want you to do is fix the fragment, similar to OCD, and the treatment is going to be ORIF. Now the treatment is to deal with the fragment, and of course you have to evaluate the size of the fragment, and its location, and whether you can fix it. This one has a twister knee. Kneecap came out of socket. She now complains of giving way. The MRI is shown. This is just trying to get you to say that people think they dislocate their kneecap and they don't, and here you want to repair or reconstruct the ACL. So again, they're going to give you some of these. They're going to have a giving way episode with no swelling. That's probably not a dislocation. It's anterior knee pain, or they're going to have a different injury. How often do you re-dislocate? These are just, I just put these in for your own edification. We now have, once you have, for a primary dislocation, 33% in my study, 43% in Marie Askenberger's study. So it's pretty high. These are from primary patella dislocations. This is what used to be quoted in the literature. This was Don Fithian's study, which is a little bit dated, but he also used emergency room data. But if you, once you have a dislocation, then you increase it quite a bit more. So these are just good numbers that you might use in counseling your patients. Again we've got these anatomic risk factors that were sort of established by the Leone group. Now can we know how to use these for re-injuries? Again I'm putting this in mainly for your edification. We do have a few studies that are trying to point that way. These are some kind of risk evaluation, and if you have three of these, you have a higher risk. This one shows immature physis and trochlea dysplasia has a higher risk. Age, sex, and BMI didn't. Ours showed that we measured trochlea dysplasia by sulcus angle, or that came up as the highest factor. Closed growth plates and a normal height had a low risk, and if you had all three of them, you had a very high risk. So again this is more for your own information that we can use these risk factors as a projection. High probability of recurrent dislocation, open growth plates, which is associated with youth, patella alta, though the threshold for surgical intervention varies, high grade trochlea dysplasia, contralateral LPD, and also a history of family history. So we need to know a little bit that when you go to an MPFL reconstruction, you have to have anatomic sites. This shuttle point often comes up on a question, and it's, you should be using some form of anatomy or imaging to look for an anatomic site when you do your MPFL on the femur. We want to try to create one quadrant lateral glide. Here we have a trainer comes to your office, 50 patella dislocations, 27 years old, tried a lot. He's been told by an orthopedic surgeon that surgery is not an option, which is weird, but he's wondering if he's corrected. He's unhappy about living with it, and his physical exam shows this tilt. He sits lateralized and doesn't correct inflection, and what is your treatment recommendation? Because he doesn't correct inflection, it doesn't mean he's out inflection, but he doesn't correct inflection, they're saying that you should do an extensor mechanism realignment, and that's the answer. This is, I think this could be debated, but this was the answer that was on one of the in-service tests. I'm not going to go through this because I'm running late on time, but when you are going with patella and quad tendinopathy, non-operative treatment, eccentric strengthening, activity modification, steroid do not use, PRP, not evidence-based at this time. And I'm just going to go to, sorry about this, guys. Did so we're going to go to the meniscus Meniscus important to know that you have a high water content high percentage of type 1 collagen. These are the two key points and Know the different know the meniscus femoral ligaments Anterior is the ligament of Humphrey posteriors ligament of Weisberg just like the alphabet the I Took this one, and I I blew this up You I think the important thing to know is that you have more mobility in the lateral meniscus less mobility in the medial meniscus And I took this picture, and I blew it up, and I'm sorry It's not in your slides But I think this relationship is important the medial meniscus is very big and wide and the lateral meniscus is very short So if you it goes PCL medial meniscus posterior horn Lateral meniscus posterior horn anterior horn ACL and anterior medial meniscus And they like to kind of trick you up on that But these relationships are important to know when you're doing ACL and meniscal surgery lateral meniscus caught covers more surface It has increased translation due to the papateal hiatus and less fixation And again these are the relationships. We just talked about So both meniscus displace, this is something that I added It's actually in the tail end of this section in the ortho bullets But both menisci have mobility lateral more than medial both displace anterior with extension posterior Reflection again lateral meniscus more than medial meniscus Major vessels are inferior geniculate for the anterior Portion and middle geniculate for posterior portion, and we do know that there is vascularity to the periphery a little bit more With in medial meniscus than lateral meniscus We call this the different zones red red full vascularity white white no vascularity red white in between so we of course try to avoid avoid a total meniscectomy because it increases contact area and Increases peak load your ACL graft force increases when the posterior horn of the medial meniscus is taken So again, these are all important points these these points that about the ACL contact area reduce increasing peak load and Of course we want to try to retain some meniscal function preserve as much meniscus as possible clearly any answer that reads that includes Preserving the meniscus is important Meniscus root avulsion the main issue here is that you lose lose hoop stresses You can see meniscal exclusion you increase because of the loss of hoop fractures. I'm sorry hoop stresses you increase peak control Peak contact pressure and decrease contact area now when do meniscus root avulsions is evolving And there's lots of information that just came out of our Academy that it does help in older people as long as you have reasonable cartilage surface Kinematic analysis of medial and lateral meniscus has demonstrated the lateral meniscus has which of the following characteristics so lateral Compared to the medial and you want to look at mobility and so they're looking at mobility So we know that lateral has more mobility than medial Cadaver study the anterior in a meniscal ligament was present in 94% of the specimens This is sort of straightforward it goes from the anterior horn of one to the anterior horn of medial to lateral Which of the following statements concerning the meniscus is accurate? This I'm going to go to I'm going to just go here because I want to just show you this is the answer that Is correct, so what's wrong with these other answers the meniscus function primarily under tension the answer is compression combination Decreases total joint surface the decreasing is wrong They do do not possess free nerve endings which they do and the meniscus possess a primary role so again You're trying to look for these key words that you pull off out that makes that sentence wrong during knee flexion meniscal motion can be described as Again, we have increased motion in the posterior horn of the lateral meniscus compared to the medial meniscus So again, they want you to know that that lateral meniscus is more hyper mobile Regarding the meniscus which of the following statements is correct? I'm here what you're looking at where the body is innervated vascular supply Inner third is is innervated and provides proprioceptive feedback Cells within the central inner regions of the meniscus are highly vascular. This is wrong collagen fibers are oriented radial radially is wrong so I the what they want you to know is that it has blood supply from the geniculates and that That it has a vascular supply, and you should know the difference between the peripherally and the inner vascular zones Biomechanical studies have shown which portion of the meniscus to be the most important secondary restraint And that is going to be the posterior horn of the medial meniscus, and that's why it's so important to save when you have an ACL Reconstruction which of the following is correct regarding the biomechanical interdependence between the ACL medial meniscus These were taken off of the oite over the last several years, and they had several questions about this again they're talking about the relationship between the ACL and the posterior horn of the medial meniscus and Forces in the medial meniscus are doubled with transection of the ACL so we know that that's at high risk when the ACL is Is torn and therefore it should try to be saved when you're doing your ACL reconstruction meniscus tear The the history is variable But we want to try to see an effusion joint line tenderness 78% when it's post your horn lateral side is less effective pain with hyperflexion McMurray's test is a type of that but pain with hyperflexion and effusion are the most common physical exam signs Know that it is quite accurate, but an MRI is quite accurate But it's false in children mainly because of the vascular supply of children And it can be a positive in a cement in asymptomatic patients, especially those over the age of 45 Now I don't find that we use this classification very much anymore But when I was growing up in the MRI world we did but what you're looking for is this tear that extends to the surface It can be posterior anterior, but but but signal changes inside the meniscus does not necessarily represent a tear that you'll see arthroscopically and they are graded and Here we have a ten-year-old that is having a gymnast seeks your help exam reveals lateral joint line tenderness and a positive McMurray's test loud painful sign When I first read this I thought they were trying to go after a discoid meniscus But they want to know which is following is true And they're trying to say that the sensitivity of the MRI is not so good in children and that the clinical exam should be used More thoroughly and so that's the answer the MRIs are never helpful of course. It's not true But they cannot be there They're not you cannot hang your hat on there When they have a positive finding and that's mainly because that type to tear the vascularity the meniscus often shows that type to tear An 18 year old rustler has a three-month history of lateral knee pain with catching and popping Exam he has full range of motion His MRI is normal, which is which likely configuration of the meniscus tear they're showing you this exam Pointing out to that So they want you to know the difference between radial horizontal bucket handle pair of beak and discoid And this is a horrible horizontal cleavage tear Degenerative meniscus is typically in an older patient a twist injury is common but it often has a setting of pre-existing degenerative changes and They can be complex Traumatic is mostly in a young person often associated with ACL tears. They often are vertical and longitudinal Here we see that double PCL sign, which is indication of a displaced bucket handle tear often not always of the medial meniscus Repair versus debridement. This is a little bit of a moving target but we want to certainly try to repair them if they're unstable which you judge by Seeing displacement on the MRI or being able to move them greater than your known displacement of the meniscus If it's full thickness within five millimeters of the meniscal capsular junction we have good success and If you can technically stabilize it and bring it together in the middle and outer third It's superior to excision now Certainly the indications of when to repair meniscus is is is rapidly changing to favoring meniscus repair Ideal is the attitude acute longitudinal tear at the periphery in a young patient in a stable knee or in the setting of a Knee that you can reconstruct These just give you some contraindications partial thickness tears which are difficult to describe but these I added this that you can't deform them when you're looking at them on in on a arthroscopy Short longitudinal tears that can't displace ten millimeters is often used as the as the length But certainly it should be that you can't displace it less than three millimeters of radial tears Controversial meaning that the radial tear does not extend to the hoop stresses when they do Repair is now being advocated Horizontal cleavage tear debrised unstable flap and degenerative tears We don't typically repair the most important factors is this rim width and the the ACL has to be intact less important is tear length age and how What if the tear is early or late? Particularly because we can enhance repair healing hemarthrosis with an ACL reconstruction synovial abrasion Trifunation of the rim trying to give you more Vascular access channels and then trying to either do some fibrin clot or platelet-rich fibrin matrix to enhance tears Particularly when they are associated with those that we know are less likely to heal These are just general rates in the conjunction with an ACL reconstruction You have the best chance of healing if it's isolated meaning that ACL intact and you have an isolated tear when you repair those We don't know what created the tear in the first place and they have less chance of healing But we still recommend repair and in the setting of an ACL deficiency where you don't repair or reconstruct the ACL They have their worst Results the inside out continues to be the medial meniscus Meniscus We have to worry about the saphenous nerve and we dissect deep to the semimembranosus. Here's that saphenous nerve and Inside out for the lateral meniscus remains the gold standard we make the posterior incision Dissect between the IT band and the biceps we beware of the perineal nerve here. We're going to see this. Here is the FCL here's a lateral gastroc. That's the interval you want. Here's a nerve and this is a little bit hard to see but there's a there's a Retractor and here's the needle and here's the needle without the retractor going right through the perineal nerve So beware of that. It certainly does happen vertical mattresses have the highest pull-out strength We favor non-absorbable sutures and the knee position should be a little bit more flex for lateral meniscus a little bit more towards extension for medial meniscus All inside techniques are popular. They are particularly helpful when you have posterior Tears and you can use them as a mixed situation avoid deep posterior posterior capsular penetration Understand the length of the articular implant that your meniscus implant you're putting in and they can cause articular damage Complications are listed. We talked about many of those but the arteries are the ones you have to be concerned about Saffron's on the medial side pop a teal on the lateral side Here when performing an inside-out lateral meniscus repair capsule exposure is provided by again They want you to do that iliotibial band retracting the lateral head posteriorly not anteriorly So that's what you're looking for 21 year old soccer player images are shown which of the following is most likely to contribute to a successful repair here. You're seeing that Double PCL sign or the displaced meniscus, and you don't see an ACL a little bit interesting choice but they want you to say that it's that you want to repair that ACL with the ACL reconstruction which will have the best results because if you have an intact ACL with a meniscus tear they have Less successful than if you have an ACL reconstruction and you repair it at the same time I think this is a little bit of a trick question which is the most favorable prognostic factor for healing and we want to go with peripheral rim and Age may play a role all of these may play a role, but this is the most important one meniscus repair technique highest biomechanical strength is vertical mattress And the best candidate for meniscus repair here. I think it's again. They're going for They're going for the fact that you have a young person that you can repair the ACL But they're not telling you that they're going to repair the ACL this 142 he's old He's got a peripheral longitudinal tear and they don't say anything about the ACL So this would do less well than this one if you repair the ACL again I think it's important to add that and here. This is a little bit odd They have one that that you diagnose a one centimeter tear which is stable to probing and the tear is located beyond the popliteal Hiatus and it has a small portion of the root. This is where I think it gets screwed up But in fairness this was taken from an oite a couple years ago And they want you to say that because it's stable you have no treatment of the lateral meniscus But I think that now with the knowledge that we know about the root tear you might do something different Here you have open growth plates And magnetism reminiscing shows that if you do have a tear so once you have a tear The most appropriate treatment is to treat it and You can try With a tear you should not try activity modification and here. They're there after repairing the Meniscus and doing an ACL reconstruction without a bony segment Over the top position and extra physical fixation Chris will talk about this later But they're trying to say that with a meniscus tear you go after that and I think that I can stop If the most of these are questions, I will say At the end our orthopedic bullets. I just added that in there a little bit small as the way that came out But orthopedic bullets are something that our residents use and then they give you the answer So good luck. Thank you for your attention

patellofemoral disorders

meniscus disorders

anatomy

biomechanics

examination

imaging

patellofemoral pain syndrome

meniscal function

ACL