That's great. So I'm going to close out here with a talk about lateral-sided soft tissues. Okay, I have no relevant disclosures. So for the lateral patellofemoral anatomy, we know that proximally we have the vastus lateralis, and then we've, you know, used the sort of terminology of the lateral patellofemoral complex, meaning that this consists of the lateral patellofemoral ligament, the lateral patella tibial ligament, and even the lateral patella meniscal ligament. So this is analogous to what we see on the medial side. The lateral patellofemoral ligament is what we typically classically think of as the lateral retinaculum when we do a release. This ligament originates near the lateral epicondyle, so about a centimeter anterior to it and just distal to it, and then attaches to the central third of the patella, and encompasses about 45% of the lateral articular surface. The lateral patella tibial ligament is more of a longitudinal fiber, as you can see here, and this goes from the lateral tibial condyle between the tuberosity and Gerdie's tubercle, and then attaches to the distal lateral border of the patella and the patellar tendon. The LPFL, the lateral patellofemoral ligament, functions primarily in extension, so we know that this shortens a little bit between in the first 45 degrees of knee flexion. And then the LPTL, the one that originates more from the direction of the IT band, is a primary stabilizer during flexion, and I think important here, as Adam Yanke has described, during trochlear engagement, and this shortens between 45 and 90 degrees of knee flexion. We know that with lateral release, this can lead to a reduction in medial stability in early flexion, so 0 and 20 degrees, and that if you progressively release this, it doesn't just cause medial instability, it can lead to lateral patellar translation as well. We know that this is because the lateral retinacular complex has a posturizing vector on the patella and adds to stability, so Christoforakis showed that if you do a lateral release, this will increase lateral translation, and so a lateral release basically decreases the amount of force that you need to laterally translate the patella. So it's because of this that we don't currently have any indications for isolated lateral release in the treatment of patellar instability. But when do we add this with our other procedures when we're treating instability? So this was a study that was just published. It was a cadaveric study where the authors looked at an intact knee, then they cut the MPFC, then they reconstructed it but over-tensioned it, and then they performed a lateral release. And what they found was that over-tensioning the MPFC, of course, led to increases in patellofemoral contact pressures, and when they performed a lateral release, this decreased the mean patellofemoral contact pressures at 30 degrees of knee flexion, although there was no difference in greater degrees of knee flexion. This was a finite element study looking at lateral release after MPFL reconstruction in a normal TTTG distance, and when they compared this to an intact knee, they found that this procedure had a decrease in contact pressure, decrease in contact area, however, there was increased lateral patellar displacement. Same thing when comparing this to a reconstructed MPFL when you add on the lateral release, decrease in contact pressure, decrease in contact area, but increase in lateral patellar displacement. Clinically, when we look at this, this was a large systematic review from a couple years ago looking at over 2,000 knees with a mean follow-up of three and a half years. Comparing the MPFL versus MPFL plus lateral release groups, overall, they were the same. So even though the lateral release group had some slightly higher rate patient-reported outcomes, these did not reach MCID, so they were considered to be equal. And then other outcomes in terms of range of motion, apprehension, rates of complications, rates of redislocations or need for revision surgery were the same, and so the authors concluded that there was no benefit to adding lateral retinacular release routinely with MPFL reconstruction. So what about with TTO then? So this was the same group that did the finite element analysis looking now at the intact versus MPFC deficient groups and then adding the lateral release and TTO. They did not add a reconstruction in this group, and they found that TTO and lateral release decreased contact pressures at all angles, and addition of the lateral release further decreased the contact area after the TTO reduced the contact area. But again, that this increased lateral patellar displacement. So I think there is the potential opportunity to offload the joint a little bit. However, this comes with the cost of instability. So when should we address the lateral retinaculum during stabilization surgeries? Well, I think really the main point is that if it's overtight and you can't get the patella reduced to the trochlea, that would certainly be an indication. How do we assess this? We use the patellar glide test and check for medial translation. The turn-up test is often described, but I think that's a little aggressive. I don't think that you should have to be able to make the patella horizontal or parallel to the floor, but I would compare it to the other side. What I like to do is to assess this intraoperatively during arthroscopy to see that you can get the patella really in the same region as the patella. If you do perform a lateral release, you should avoid proximal extension into the vastus. You should avoid distal extension into the lateral patellar tibial ligament. And a lot of people will consider a lateral retinacular lengthening to serve as a restraint. So technique-wise for the release, as I said, limiting this to really just the articular surface. This can be performed arthroscopically or open. The arthroscopic release disrupts the capsule layer, and so there is a risk of hemarthrosis. So important to do this without a tourniquet or let the tourniquet down afterwards. A comparison of arthroscopic versus open release showed that arthroscopic releases did better in terms of outcomes and had less iatrogenic medial instability. The alternative is lateral retinacular lengthening. So this allows you to provide a restraint to medial translation. This is done through an open lateral incision. You dissect down to the patellar retinaculum. And then basically this is a Z lengthening. So you incise and develop the superficial versus deep layer, which is being done here on a catameric knee. And then going through the deep layer and then putting these together with the anterior edge of the deep to the posterior edge of the superficial and sewing that together. When comparing these two, an old study looking at arthroscopic release versus lateral lengthening for patellofemoral pain showed improved lysome scores with the open lateral retinacular lengthening, with no differences in terms of range of motion or strength or thigh circumference. An L-emergence study looking at lateral release versus lengthening when combined with NPFL reconstruction at two years showed worse Pujala scores and more medial instability in the lateral release group. So I think it's important to talk a little bit about medial instability. Of course, this is much less common than lateral instability. But if you've had a patient who's had a prior lateral release, I think this is important to recognize. The patients don't always know which way their patella is going. And as we know, medial instability is associated with lateral instability. The imaging won't always show these findings. And so this is primarily a clinical diagnosis. This means you have to look for increased medial translation and look for medial apprehension the same way we look for lateral translation and lateral apprehension. So I always check for both in all of these patients. When they do have this, there are multiple options. Ben Hayworth has shown good results with a lateral retinacular repair, retinacular reconstruction. Also, many different options for this, including using a free graft, analogous to an NPFL reconstruction, quad tendon graft, IT band. There's a V-shaped one that Adam Yankee has described with a proximal distal reconstruction. And then Rob LaPrade has described the IT band and patellar tendon, which is a technique that I currently use and I'll show in one of the cases. So with this, the treatment algorithm, I think, is important to consider when somebody has medial instability. I mean, one, you have to confirm the diagnosis by physical examination. If they've had a lateral release, I always like to get an MR arthrogram. I know it's a little unconventional, but that helps me to localize the defect, whether it's proximal, middle, or distal, because I think that has to do with what you want to do with your reconstruction or repair afterwards. And then I'll brace them. So I'll put them in a medial stabilizing brace. So it's basically taking left knee patellar J and putting it on the right, or vice versa, to confirm that it really addresses the patient's symptoms before we actually do this. Because these types of symptoms are not as pronounced as a classic lateral patellar dislocation. And so you want to make sure that you're going after the right thing here. Intraoperatively, I assess the mobility. And then I look arthroscopically at if they've had a lateral release previously, where that release is, whether it goes into the vastus, whether it's limited to the retinaculum, or if it goes distal into the patellar tibial ligament, which is, I think, where primarily the stability comes from. And then I do kind of a focused reconstruction or repair of the deficiency. And then after that's done, you've reconstructed that sort of posturizing vector, you can reassess the lateral stability. Because a lot of times, this will address any sort of lateral instability that they have. So a couple of cases here. So this one is a 22-year-old female. She had previously had a proximal tib fib reconstruction. And then because she was having mechanical sensations in the anterior knee, she underwent an arthroscopy. And immediately after that surgery, she reports having clicking, locking, popping when going from extension to flexion that requires manual manipulation. On exam, she had no effusion, no tenderness. She had three quadrants of patellar mobility medially and two laterally with apprehension medially. And when they are unstable medially, they don't really click over the condyle. It's more that you can kind of get your thumb right into the trochlea. She had an audible and palpable clunk going from extension to flexion that happened right around 30 degrees of knee flexion when the patella engaged within the trochlea. And if I gave her kind of a lateralizing force, this corrected that normal range of motion. The rest of the knee exam was unremarkable. On imaging, nothing too remarkable. This is the MR arthrogram. So as I said, if they don't have an effusion, this allows us to see where the defect is. And in her case, this was all proximal to the patella. And so she had already completed many, many months of physical therapy. So we did a trial of a medial patellar stabilizing brace and she reported 100% relief of her symptoms. So then we proceeded with surgery. So this is the EUA. You can see here, I can kind of get my thumb right into the trochlea. And at the time of diagnostic arthroscopy, you can see the distance between the patella and the trochlea. This is five millimeter probe. So she's lost that posterizing vector. The picture on the right shows the lateral retinaculum, which is intact. It looks good here. But if we look more proximally, we can see this is now the vastus coming towards the patella. And so the pictures on the right show that I've localized that area and basically opened it up a little bit. And I did kind of a combined open and arthroscopic closure of this. This is what it looked like afterwards. But I think that when we're thinking about medial instability, if they've lost that ability to contract their vastus, then that has to be repaired. And I don't think a reconstruction can overcome that. And so that's why I think it's important to identify that. So afterwards, she had resolution of her mechanical symptoms. You can see the before and after picture of the sunrise view, I guess, taken at this. We did this at 20 degrees showing reconstitution of her posterizing vector. Second case, this is a 29-year-old female, reports a long history of anterior knee pain, playing college lacrosse. She's had two prior surgeries at an outside hospital. One was a fat pad removal. One was a removal of a lateral cyst. And she keeps feeling that her kneecap is out of place and she has to reset it. On examination, she had healed incisions, small effusion. She had an area of kind of dimpling in the interlateral knee right by her portal. Similarly to the last patient, she had three quadrants of patellar mobility medially to laterally with increased, sorry, I should say apprehension going medially. Otherwise, her exam was remarkable. Radiographs, not too much to comment on here. This is an MRI, I think, without arthrogram, but she had a bit of an effusion. So this helps. You can see vastus looks okay. Lateral maculum looks okay. Now this one is distal near the patellar tendon. So the patellar tibial ligament looks like it's disrupted. So she went through physical therapy. She continued to have symptoms. I put her in a medial patellar stabilizing brace with, again, she recorded complete resolution of her symptoms. So here's the examination under anesthesia. This is not video. So she has a little bit of increased lateral translation, increased medial translation. These are her arthroscopic views. Again, the patella is way up higher than you would expect. And the lateral retinaculum, these pictures are not that clear, looked okay. If you look at the bottom picture, so I was backing up kind of through the lateral gutter, and then I came to this huge defect in the patellar tibial ligament. So this is basically looking at the bottom edge of the lateral retinaculum. This is where she had had the cyst debridement, where they had taken down the synovium and the patellar tibial ligament there. So because her defect was distal, I chose to proceed with a distal reconstruction. So this is a technique described by Rob LaPrade, taking the central third of the IT bands in the left picture, and then a lateral slip of the patellar tendon, and then crossing those over, and then finding a good tension to that and sewing them together without over-tightening. And so this is before and after she had resolution of her mechanical symptoms. And that was symmetric, was with reconstitution of the sort of posterizing vector, as you can see. So with the cases, I think it's important to have a high suspicion in these patients who have had any arthroscopic treatments for anterior knee pain. So they don't always say that they had a lateral release. Sometimes it's just a debridement. Certainly, the lateral release should set off red flags, but it might be something else. It's important to identify medial instability on examination and know that it's going to be associated with lateral instability sometimes. Confirming this with a medial stabilizing brace, I think, is really important, both for you and for the patient. Others have used backwards KT taping, which is an option as well. And then one thing that I've learned through these cases is identifying the location of the defect and trying to address that specifically instead of just reconstructing of the lateral retinaculum for anybody who is medially. So in conclusion, the lateral patellofemoral complex has a role in patellar stability. It has that posterizing vector, which is important. And when you release this, this can decrease the patellofemoral contact pressures, but it can also increase instability. So we have to be careful about this. If you perform a release, this should be minimal. And to make sure that you don't go too far proximal or too far distal, the lateral retinacular lengthening is a nice option to limit medial instability. But don't forget, if you're doing this, you still can't go too proximal into the vastus. And so we want to make sure that we're still in the right place. And lastly, medial instability should be identified and not mistaken for lateral instability. Thanks very much for your attention. So we're coming up on time of the formal aspect of this ICL, but I'm going to have the panelists come up. And anyone who wants to stay and ask a few questions, we can probably answer them for the last five minutes or so. Any burning questions I was told to ask from the group? Yes. Sorry, just to repeat. Did you ask with the post-op rehab probe? Okay. So for me, when I'm moving the tuberosity, two weeks non-weight-bearing, two weeks weight-bearing, two weeks non-weight-bearing, two weeks one-third, two weeks two-thirds, full weight-bearing at six weeks, getting post-operative imaging, first visit to confirm hardware positioning, shingle placement and all that. And then before running, cutting, pivoting, jumping, confirming at least early healing. And if you want to look specifically at the anterior cortex, sometimes you still see, if you're doing a distalizing osteotomy, they're the ones that take longer. Almost all of the hinged medialization, anterior medialization, that's not a problem. They will heal. You haven't released the hinge, the periosteum's intact. It's when you release it and you can see early sub-periosteal or periosteal healing crossing over that distal cut two months, three months, and then you know it's, you're pretty sure it's going to happen. But I would probably get a third set of films at six or seven months just to confirm. Okay. for reconstruction. Yeah. And then does not keep the sterilization compared to the two strata. Yes. So the case is a one strand. Yes. And a distilization. Yes. Did you consider doing a two strand MPFL? Yes. So you didn't have to do those yet? Yes, so that's a great question. And this is unpublished data, and I probably shouldn't have even brought it up because it's not been peer reviewed yet. There is literature that shows a distilization following MPFL reconstruction. Three out of four papers show statistically significant distilization between CDI of 0.10 to 0.22, whether it's a single bundle or double bundle. We just looked at about 250 or 300 cases from Hopkins, UVA, Cleveland Clinic, and Harvard. And we found that if you use a single bundle, you get no distilizing effect at all. Whereas if you use a double bundle, it averages a CDI of about 0.8 to 1.0, which correlates with about 4 or 5 millimeters. So some studies, you get as much as a 0.22 CDI distilization with a double bundle MPFL reconstruction. We're not sure why. Probably because it's not a purely, truly anatomic MPFL reconstruction. So that's why it's so important for you to look at your own technique. And go and do some CDI measurements pre and post-operatively on your MPFL reconstructions. And then incorporate that into your algorithm. Because if you have a borderline ALTA, say you're at 1.3, 1.4, and you're thinking about doing a distilization, if you use a two bundle MPFL reconstruction, you may not need to. I'm going to counter that opinion. Because Spike Erasmus has shown that if you pull down the MPFL and you create significant distilization, that you're probably over-tensioning it. In addition, if you look at where people put a two bundle, you have to look at the length of the cartilage on the longitudinal sagittal view. And oftentimes, it's below that 50%. So what you're actually doing is kind of putting it into the area of the MPTL. And so that can create nose diving. Now, Petri Slampa is the one that first showed that if you, that what's probably happening is that we are tearing the MPTL. That was shown in our study that we looked at MRIs, that the injury goes from distal to proximal. So you almost always tear the MPTL, but yet we rarely reconstruct it. So if you want a small distilization, maybe reconstruct the MPTL. So I think, and Laura Hemstrom showed .22, not two point. So .22 may be significant from a statistical, but it's not clinically significant. So I think I just have to be careful with that. Because I can't believe that you can pull the patella to, you know, .2 or two. Yeah, .2 on a CDI, though, is a centimeter. Yeah, .22 is like a centimeter. I agree completely. I don't, I mean, I've always thought as an MPFL reconstruction. Here we're talking about we've mastered MPFL reconstruction. When do you do an osteotomy? And now we're talking about MPFL reconstruction. I don't think you ought to get a distilizing effect from an MPFL reconstruction if you're doing it the way that I think of doing it. I think it's a passive soft tissue restraint. And it's not designed to realign or reposition the patella, unless you've got a badly subluxed patella to begin with. And then maybe you ought to be doing an osteotomy as well. So, go ahead. I just wonder if that's a measure of, you know, initially the patella is out of the groove. So it's not perfectly engaged when we're doing the measurements. And then you do an MPFL and then it's centered in the groove. So is it distilization or is it actual just centralization? And I worry if we're pulling the patella anywhere with MPFLs, we should probably be doing something else. But it's interesting food for thought. I'd also just add to Andy's point about the 33.5s. I use 5.0 headless. So I have a series of over 40 of those with a much reduced, so two 5.0 headless screws and a much reduced number, at least in I think most of them are over a year now. I'll publish it so that we have that in the literature too. So I think that's another option for people as well. Yes. So you're talking about what Philip Nye and Bob Magnuson published. So what they're talking about is pulling it down and where the patella tendon used to be putting a staple there. They actually don't do that anymore, and you'd have to ask them specifically why. But there was a concern that it maybe doesn't help, and it might end up maybe potentially causing some necrosis or damage to the patella tendon. And so it's a nice thought. What they tried to do is to reconstitute where the patella tendon inserts on the tibia by putting a staple there or tenodesing it. But I know that they don't do that anymore. And again, it's a clever idea, but I think it's a little bit risky. We don't know what happens to that distal tendon. So what are some indications for lateral retinitrile lengthening or release of isolated MPFLs based on the studies of now shown that it's not needed, I guess, in total, but I usually just see some patellar tilt after doing the MPFLs. Are there suggestions for making that decision? Yeah, so I usually do this during the diagnostic arthroscopy before the MPFL. I see if the patella can be centered within the groove. In my experience, it's pretty unusual for the patella to be stuck over to the side in a simple MPFL reconstruction. And it's typically for the TTOs with that sort of chronic instability where you just can't get them centered. And of course, for those, you have to be able to. But at least in my practice, if they can be centered, then I don't add that. I don't know if anyone else wants to comment. I almost never do a lateral release for an isolated MPFL reconstruction. Most of the time, they have hyperlaxity. Most of the time, the patella is too loose. So it would be very unusual in my practice. I guess I'll also make the decision at the time of the diagnostic arthroscopy. But I'll have some inkling from lateral X-rays for tilt and then axial imaging. I'll check my quadrants in the office. You know, one quadrant translation or less. Try to get my finger, get it to neutral. But then I'll look for medial, take the shaver, run it along the lateral gutter, try to lift up. And if it's still tight, you know, then I'll consider doing it. So I'll move my MPFL incision a little more lateral and make it a little bigger because it's easier to do the lateral lengthening, for me, open while I'm looking sort of on the lateral side. And I can sneak over to do my medial MPFL where it's much harder if I have a small medial incision to do anything lateral open. You know, I end up putting a pin where I do a short tunnel for my MPFL and I put a K-wire in and I look for it on X-ray. And what I found is that if I can just say that this is the patella, so I have my knee at 20 degrees and I put my pin here and I'm trying to get a fluoroscopy view and I can't get that patella down. So in essence, you're doing a medial patella tilt test. And so I couldn't figure out why I couldn't get the pin to be level neutral to the ground. So I kind of found into that by accident. And so I use that sort of medial patella tilt test in early flexion as soon as you're engaged in the groove. And if I can't get that patella to neutral, not positive when it becomes neutral. I mean, we don't know exactly where you have a, you know, you neutralize that patella. But then I think about a lateral lengthening and I do only lengthenings. I'd like to ask Miho, how do you reconcile, you know, for the lengthening we talked about, superficial oblique, deep transverse, and then capsular layer as the Z lengthening you showed. How does that jive with Adam's description of the anatomic structures, LPFL and LPTL? Yeah, so that would be lengthening the lateral patella femoral ligaments. Because the tibial one is, is this what you're asking? The tibial one has a distal attachment. You're saying why is that? I guess the superficial oblique to my understanding comes with the IT band and goes up to the lateral aspect of the patella. And that's the layer I typically peel down. And then I see transverse fibers. And then I do my cut two centimeters posterior. And I can go through the capsule layer if I need to get into the joint or not. Yeah. I just don't, I don't see the picture how that works with what I'm doing surgically. Yeah. No, I think, so there's not a ton of anatomical literature on this. And I was looking through it too. My understanding is that there's kind of like, you know, a blending of the tissues as it gets closer. So it looks like from, and I've only done a couple dissections on these. The bottom half of the patella has like both sets of fibers. But you start to see those sort of vertically longitudinally oriented fibers. I guess my take home, maybe your thoughts. I'll use atoms to guide my reconstructions if indicated. And perhaps not to guide my initial soft tissue dissections for lengthening. Or if I'm just considering a repair. Yeah. You know, if you go back to John Fulkerson's study, I have to smile a little bit. Because we didn't have all these beautiful anatomies. And we weren't able to take pictures. And even if we did, they didn't publish them because they were too expensive. But he did this little line diagram. And I think it was published in late 80s or early 90s. It's actually quite elegant where he shows the different orientation of the fibers. And I think it's lateral patella femoral ligament. What I would find interesting, and I've thought about this as you talk, sometimes it's like one centimeter in length, you know, caudate to cephalate. And sometimes it's like two and a half centimeters. And so, so varied. And what would be kind of interesting is if when we did our lengthening, we would maybe take a little snapshot or measure the length of the patella or the length of that and maybe just pool our results. Because it is so, so, so variable. I mean, we don't really know. And the other thing is Adam Yanke has Jorge Charla helping him to do the anatomy. And he is one of the best anatomic dissectors ever. He's just really got elegant work. So, maybe he finds things we don't. Okay, great. Well, thanks so much to our panelists and our audience for a great session.

lateral-sided soft tissues

patellofemoral joint

lateral patellofemoral complex

lateral retinaculum

patellar instability

medial instability