So, hello everybody. Welcome to the Multi-Institutional Sports Medicine Fellows Conference. I'd like to ask you all to please mute your audio for us if you would, so that our speaker can speak without a lot of this reverberation and feedback. That'd be much appreciated. I also am gonna try to help keep people muted from our end over here. This is being recorded and it's gonna be transferred to the AOSSM Learning Management System and available. This week's talks will be available next week, starting next week in the AOSSM. So, if you wanna hear Dr. Farrow over and over and over again, he keeps replaying the talks. And then, again, I ask you to submit your questions on the chat and we'll try to get to them at the end. And we'll also ask if some of the faculty wanna contribute some discussion. Please, actually, either there's a raise hand button or there's also a, you can just chat me and I'll unmute you. For some reason, Jessica Mowbray, I can't mute your phone. So, if you could do that, I'd appreciate it. But we're very fortunate tonight to have Latul Farrow, who's the Program Director of the Sports Medicine Fellowship at the Cleveland Clinic, Associate Professor, and just a patellofemoral guru and God and lover of all things patellofemoral, to give us a talk about the NPFL and his journey through, that brought him to the patellofemoral joint. So, without further ado, Latul, thank you for doing this. Yeah, thanks, Mark. Thanks for putting this all together. I think this is a great lecture series and hopefully I can continue to bring a high quality to this series. I think we got off to a great start last week with Dr. Ciccotti and Dr. Dugas and hopefully I can continue to do good things. So, I've got nothing to disclose. So, what is this talk gonna be about? It's a case-based approach. We're gonna review some of the current literature over the last couple of years, because there's been some great studies that have come out. And then really talk about my practical approach to non-complex patellofemoral instability, my personal experience, and also what I understand from the evidence-based medicine. Hopefully answer some key questions, what to do with the first-time dislocator and how we can manage recurrent dislocator. You know, what we're not talking about is, you know, this won't be a basic anatomy and biomechanics review. We assume that everyone is well up to speed on that. We're not talking about patellofemoral pain, also something I love, but I think we can breathe a sigh of relief on that one. And we're not really talking about cartilage here. You know, certainly these can have some concomitant cartilage injuries, but that opens up a whole nother can of worms that's kind of beyond the scope of this talk. So, it's nice when you can put things into black boxes or little black boxes, basically. So, is it pain? Is it instability? And the reality is for people who live in this world is that a lot of times, you know, patient may just have pain. They may just have instability, but many times there's a gray area where they have pain and instability. It makes it interesting, but today we're mostly talking about those patients with instability and pain related to those instability episodes. So, we look at patellofemoral instability. Is it all surgical? We know it's common, but does most of it, if not all of it, need surgery? I would say no. Yeah, I like to know, is it a first time dislocator? Are you a recurrent dislocator? And what's important? Because why is this important? Because it lets me know what's their risk of recurrence, allows me to counsel patients. I'm less likely to recommend non-operative treatment for somebody who's been dislocating for years. And then it also determines what type of treatment that we're providing for the patient. Some of the historical literature shows that, re-dislocation rates after an index dislocation is somewhere around 50%. We know that a lot of those patients will be copers, meaning that they may subluxate every now and then, but they can live with this. So, when you look at the failure of non-operative treatment, it's somewhere around 33%. And I think as we go through the literature, you see that that number holds up time and time again. So, nearly half these patients will never dislocate again. This is not an ACL injury, right? So, most patients who have ACL injuries who are active, they need to have surgery in order to stabilize their knee. Patients can cope with this. As a young team doc out at University of Arizona, this is one of my first high-profile patellofemoral instability patients. He dislocated his knee when we were out playing Washington State. He missed a couple of weeks. We got him back, braced, and obviously finished out his career at Arizona successfully and went on to win a Super Bowl. And he joins the ranks of people like Patrick Mahomes, who have also had patellar dislocation who have not needed surgery. And so, these can all do real well, right? So, how do you treat non-operatively? Not quite sure. So, one of the recent systematic review in OJSM looked at this. And again, there's that number again. About 30% of patients will re-dislocate. And what they found is that there's no real clear-cut approach to how to treat these, whether you brace them, whether you rehab and what sort of rehab, but there's no approach that was really superior. And they found that patient-reported outcome measures did improve, but did not return to baseline. So, even though non-op can be successful, one-third will continue to dislocate, and most of these patients won't be normal. This study kind of looks a little bit deeper at that. And they actually compared a cohort of ACL-deficient patients to patellofemoral instability patients. And what they found is that the COUS, and it's really not a surprise to people who take care of patellofemoral issues, but the COUS was actually worse than the ACL-deficient patients. And they found that patellofemoral instability can really be as limiting as the ACL-deficient needs. So, this is, you know, a little bit eye-opening. So, these injuries are not truly benign, per se. So, that's less than one. And some of these patients may have some residual disability. Looking at another study, another systematic review of meta-analysis from AJSM in 2019, again, their pooled re-dislocation rate was about 33.6%. And I like this article because they really go into some of the risks that we look at when we evaluate patients. So, we look at younger patients, patient with open physis, cochlear dysplasia, elevated TTTG, and patella alta are all important factors for recurrence. And pay very special attention to the cochlear dysplasia. That odds ratio is 4.15. So, that's a pretty significant thing. And what was nice, these authors said, so, what you want to do is have risk calculators and really be able to use this information to counsel your patient. So, if they're like our quarterbacks, no real major risk factors, their risk of re-dislocation is pretty low. But by the time you get to three of those risk factors, you know, these patients are almost assured that they're going to re-dislocate again. So, those are maybe patients that you may want to be a little bit more aggressive at recommending surgery. So, not all these patients are created equal. You want to kind of have an a la carte approach. And you want to assess for these risk factors when you're evaluating these patients. So, how are these articles significant for me? So, I think it allows me to better approach my patients, better have better discussions, that they may not be normal with their knee and they may have some limitations. And really, again, those patients with dysplasia who are younger, open physis, elevated TTTG and patella alta, those things matter. And what a lot of these studies did not address is the patient with the J sign. Be wary of that. Because those patients, I think, have some of the most profound instability and, again, may be more likely to need surgery. So, lesson two, you want to risk stratify based on anatomic factors. This is more than just tying up some collagen in between the patella and the femur and calling it a day. So, how did my surgical philosophy progress? And obviously, this is a work in progress we're forever learning. So, as a young medical student back in the late 90s, I spent some time with Jack Andrush on a project, you know, sort of pre-residency, looking at the albiosteotomy, it's a trochlear osteotomy that's rarely performed in patellar femoral surgery. But that really got the spark for me. And that's where it was my beginning. And we all know that God has a very special place in heaven for the person who takes on patellar femoral work. So, through my residency, great knee docs, but for the most part, our answer for instability was lateral release with or without a focus in osteotomy. And obviously, at this time, didn't really know much about the NPFL, never had a chance to see it during residency, read about it while studying for boards, but didn't really realize if it was a true thing or not. And then once I went on to my fellowship at the Cleveland Clinic, Jack Andrush, who's an expert clinician, master surgeon, and a brilliant scientist, really showed me the way when it came to the NPFL. So, showed me the anatomy of it, and also taught me to respect the lateral retinaculum. So, to that end, you know, the great renaissance, you know, changing my thinking about what the lateral retinaculum actually does, it's actually an important structure. And in my practice, and over the years, I'm not sure lateral release truly has a role for me in the patella femoral instability patient. Maybe in a patient who walks in and their kneecap's been dislocated since birth, and they're so contracted laterally, the only thing you can do is to release them in order to balance the soft tissues. But in your everyday instability patient, isolated lateral release does not serve a real function for me. And the literature is all over the place in terms of the outcomes with this. And what I also learned is iatrogenic medial instability is a real thing. Patients do have medial instability after isolated lateral release. So, biomechanics study back in 2007 found that lateral retinacular release actually helped to destabilize the patella femoral joint. Bob Burks and a group out in Utah in 2008 also showed that the lateral retinaculum contributes about 10% to the force to lateral translation of the patella. So, we know the NPFL is 60%. That's your major soft tissue structure. But the lateral retinaculum also contributes, and that's gonna be very important. So, lesson number three, you gotta respect the lateral retinaculum. So, Jack Andrews taught me the way on how to find the NPFL, how to reef it or imbricate it, and then also how to recon the NPFL. And then off I went out of the nest out to University of Arizona, kind of Lone Ranger. And as we were sort of talking before the call got started, when you show up in town and say you're a patella femoral specialist, your practice builds quickly. So, I got to do a lot of repetition, had an opportunity to build and really specify my practice and got to refine my surgical techniques. So, this is one of our first patients, one of my first sort of more complex patients, I guess, that I saw in practice. This is a daughter of one of our psychiatrists at the hospital out in Arizona. She had right knee instability. She had been dislocating since she was seven, had a prior Fulkerson by one of the other docs in town, along with a lateral retinacular release. Painful recovery. She's okay now, but was coming in for her other knee. So, lateral X-ray. She has a super patellar spur. She has a positive crossover sign. Her ketone Deschamps index is 1.2. So, a bunch of borderline kind of factors when I look at it in terms of my practice. And so, it's something I don't really blink an eye at when looking at soft tissue surgeries. Her TTTG was 14 millimeters. So, not really that elevated, but we can also see that she's a little bit dysplastic. Not bad. She's got some lateral translation. She's got patellar tilt. She's got a negative congruence angle. So, I look at this and put all these things together and say, yeah, I think we can do this with just soft tissue balancing. Sorry about the sound here, but this is her intraoperative pictures. So, this is the site she had the Fulkerson on. So, she's still very unstable. Because she never had her medial site addressed just the Fulkerson and the lateral release. And essentially, her other side had the same exam. So, we were gonna remove her hardware on this side. And then her contralateral side, we were gonna do our soft tissue balancing. So, she had arthroscopy. She had some chondrosis on her patella. So, we did a chondroplasty. But she had an open lateral retinacular lengthening along with her NPFL reconstruction. And this is her post-op after she's recovered. So, this is her Fulkerson side. So, she still has a J sign on this side. So, J sign pre-op, J sign post-op after Fulkerson. And then her other side that we did, we'll come up shortly here. We just did NPFL, lateral retinacular lengthening, and much improved tracking, much easier recovery process. And after this surgery and she recovered and she really knew what a stable knee felt like, she actually asked us to do her other side before I left Tucson. And we actually did her other side, did the NPFL. And from all I know, I think she's been fairly happy ever since. So, what did I learn out in Tucson? That TTO is rarely needed in the patella femoral instability patient, even with increased TTTG. And we'll talk about some of the literature that supports that. We do need to address patella alta and carefully manage the lateral retinaculum. Again, I don't release it, except for those very severe cases, and really lean on lateral lengthening when needed. And we know that iatrogenic medial instability is a real thing, but you really want to have kind of a la carte care for these patients. Again, individualized to the patient. So, after the desert or the common error, we step into the Cleveland Clinic and I've been here for the past nine years. I've been really honing in more on the anatomic reconstruction of NPFL. You know, really trochlear dysplasia has been a bigger part of my practice. And then really looking at some of the complex instability patterns. So, questions. So, this is obviously talking to NPFL. How do you get it right? So, where do you put it? Basically put it where it goes. So, this study by Baldwin was one of the early studies looking at some of the osseous anatomy and soft tissue anatomy of the NPFL. And we know that it inserts somewhere or it attaches somewhere between the medial epicondyle and the adductor tubercle. You know, we did some research looking at its relationship to the growth plate as well as these bony landmarks. And there's a small ridge in between the adductor tubercle and the medial epicondyle attachment of the medial collateral ligament where the NPFL attaches. We've also done some additional anatomic work looking at the NPFL. And we know that in those patients or any cadaver specimens that, you know, it's a pretty wimpy ligament. You can actually see the hemostats through the ligament. But we know, again, just from our anatomic dissections that, you know, it sits between adductor tubercle and the medial epicondyle. So, this study by Smirk and Morris looked at some of the tensioning of the NPFL. And again, anatomically speaking, you really wanna concentrate, so upper third of the patella. The course is just underneath the VMO here. And it's the ligament, obviously. And when you look at the ideal points, so these gray points here on the femur and the patella, this is sort of where you wanna be, right? Where your attachment sites are. And if you are gonna air, don't air proximal when you're doing this because the graft will get tighter in flexion and you're more likely to stretch out. So, you wanna kind of air distal, maybe a little bit anterior if you have to air anyway. But just get it right into the right place. And I think that increases your chances for success. So, lesson four, let's get the femoral tunnel correct and avoid proximal placement. So, to do that, I used to do this anatomically and as with any surgeon with the N of one. So, I used to fill landmarks and put my tunnel there and I get a post-op x-rays and almost always we were right on point. But I had one patient that actually did well, but I got an x-ray post-op and the tunnel was somewhere in left field. And from that point on, I went to using Shadow's technique. And this was years ago, just to kind of help with my placement. And it's a good technique to use. I think it is reproducible amongst, from person to person. There may be some variability in between surgeons, but for the most part, we all kind of get into the ballpark. But at the end of the day, you have to trust your anatomy and use this as a tool to help get this into the right place. Because where we place this may vary based on how we draw our angles on the poster cortex of the femur. And what we determine as being the poster aspect of the condyle, and that can result in a little bit of variation. But in our study, no longer, no more than a centimeter off with respect to displacement. So again, we know in kids that you want to put this beneath the growth plate, because there was some controversy prior about where the NPFL attaches. And we know that, you know, when you look at inter-observer reliability, you know, we kind of get somewhere in a ballpark when we're placing this femoral tunnel for the NPFL. So again, in kids, it goes distance to the growth plate and it's right adjacent to the growth plate. So you don't want to drill across the growth plate in kids. Instead, you want to drill anterior and distal because the posterior part of the growth plate is concave. The anterior part of the growth plate is convex. And that kind of increases your safety zone, you know, for the NPFL placement. So this is one of the pediatric patients that we did a few years ago. So 11 year old, again, subluxating since she was seven. Recently had three frank dislocations. She's premenarchal, so that's important because she's not yet hit her growth spurt. Her parents are tall. And so that's something that you want to take into account. But again, you know, J sign, this is unlikely to get better with bracing and non-operative treatment. Her ketone dechant was 1.2, so borderline. She had a positive crossover. Her TTTG was 15 millimeters. So high, but not overly high. And then she had dysplasia, so de jure type A or B. So plan was NPFL reconstruction, lateral retinacular lengthening. Some people are proponents of doing a non, so doing this without a femoral tunnel. So they can loop it either under the MCL attachment or loop it around the adductor tendon. And I think those are by definition non-anatomic. But if you want to do this in kids and you want to avoid the growth plate, I think there's enough literature out there there's safe ways to avoid that. And so, you know, we go through our shottles technique, you know, airing just a little bit distal, but it looks like we're right at the growth plate, right? But we know that because of the way the growth plate undulates, that really you're looking at the central area of the growth plate here, and when you're looking at a lateral. In reality, your starting point is the growth plate. So long as we aim distal and we aim anterior, and even if we have to air a little bit distal again for, you know, tension in the graft, that's actually not a bad thing. So we can actually do an anatomic reconstruction. You know, she's done well, three years post-surgery, no growth arrest, and she's gotten back to all of her activities and she's very happy. So what are we doing currently for NPFL? So I think I use Autograph for all my patients. I put a single tunnel on a femur with a screw, so a blind socket. And I know some authors are big proponents of fixing it on the patella first and then sucking it into the femoral tunnel. I think I have a little bit more control by doing it this way. So I fix it on the femur, and then I flex the knee about to 30 degrees, and we put the patella where I want it at 30 degrees, which is right in the center of the groove, and that's where we fix it. I think that's done pretty well for me in terms of tensioning. We get our patella tunnels high on the patella, and we just basically tie these in. So I use all suture anchors, so Smith & Nephew Q-Fix anchors, because they're easy to place, and they're easy to control, and you don't have to worry about metal or things penetrating the articular surface. And again, when you talk about Autograph versus Allograft, there's a recent systematic review out of Ohio State, as well as a clinical study out of Ohio State, which showed that there's really no difference between Allograft and Autograph for the NPFL. And even in PEDS, this one is from San Diego, also did not show a difference. So if you want to use Allograft, the literature supports you. Again, I just like using the Autograph, and that's my choice. So the other big thing, this is not MIS surgery. So I don't like doing this through a keyhole. I think you have to get in there and appreciate the anatomy. You have to respect the anatomy, and you have to address the things that need to be addressed. So next patient this is a 17 year old male. He's pretty much skeletally mature. Recent recurrent patella femoral instability. So again he had a J sign. TTTG was 19 so he's really borderline. He's just got mild dysplasia and has severe patella ulcers. Rare that we you know I see patients who are 1.2 1.3 ish but you know he's 1.47 so that's not even a tweener so he's up there pretty high. And so when you look at his imaging so this is the sagittal of his MRI and you know you look at this and you say well this looks like a pretty nice groove well this isn't actually the groove this is actually the cortex of his femur. So this thing is basically teetering above the trochlea right on the femoral cortex and so that I think just doing an NPFL in this situation you set up for failure. I think it's me much harder to keep this patient located. So this is a one of the pearls so when I look at these patients surgically I like to look from a superior medial portal and we're looking distally so you really see right down the pike and you can see exactly what this patella is doing. So he's got a empty trochlea sign so the patella is somewhere out in left field and so this patient our choice was NPFL reconstruction, lateral lengthening and we did a patellar tendon shortening in him. So the lateral lengthening so you got to address the tight lateral structures if they have tilt if you can't ever to patella and it's a slick technique that I you know it's pretty easy to do and this you can do through a smaller incision but you got a bigger incision because we had to do a lot of other work for him but this is the way we do that. So this is after we divided the retinaculum so you can see the border so we've divided the retinaculum and we're pulling that laterally. This here is all the capsular tissue this is pretty stout tissues as well even once you release the retinaculum you still can't ever at the patella because of the capsular tissue and so our next step we kind of measure out exactly how much we want to lengthen this and usually it's 1.5 to 2 centimeters that I'm trying to lengthen and then so now we've transected the capsule along the posterior edge 2 centimeters away from the patella and then finally you know we stitch this together to do our lengthening so you can see the retinaculum here you can see the capsule here and this is about our 2 centimeters of lengthening and it's pretty easy procedure to do but does maintain your lateral structures which I think is very important for balancing the joint that's what you need you need to balance the joint and so that's our lengthening and then you know also for him so our next step was then doing the patellar tendon shortening so you want to do this before you fix your NPFL because that changes the height of the patella which may have some interplay about where you're you know you're lengthening your graft and so I will do this if the TTTG is not severe because if it's severe then you have to add a osteotomy you can distillize through the bone but if the senses TTTG was not severe we just wanted to address the soft tissues so this is a very busy slide again these slides will be available for you guys and so you can see what the the reference for this is but this is by Jack Andrush and goes into this technique and it's kind of a little daunting when you think about this because you're actually cutting through the anterior half of the patellar tendon and there's a very complex suturing technique to kind of bring all this down so you end up as you bring this patellar tendon down and basically reef this or imbricate it you end up with this lip of tissue back here that you can then tie in and re-tuck that into the back and what that looks like intraoperatively so we made a couple extra marking so this is an extra mark but you know you can't erase them during surgery so so this here is the patella this is the mark that we wanted to make for our one centimeter of shortening and basically this is where our reefing sutures are coming through to kind of pull up the redundant portion so this is after we've cut through the anterior half of the patellar tendon and now we're putting those these are absorbable stitches that we're putting in that we use to basically pull that that folded tissue back up and then we put permanent sutures in to kind of basically refall that tissue back down together and you kind of see those are coming up under our flap here and once we pull everything down we put some more sutures in to kind of get all those things tightened up and this is kind of the the finished product and the whole goal is to bring the TTTG or the CDI down to one if you can so and then the NPFL reconstruction so as I mentioned we'd like to put a socket on the femur and then these all sutures suture anchors on the patella the reason why I use all sutures because I don't necessarily like drilling tunnels through the patella I worry about patella fracture and I think this works well we have a lot of backup fixation because we we suture into the periosteum of the patella and the soft tissue so this here is the reefing technique that Jack Andrus has described or published on so basically we take down the NPFL that's the capsule underneath so this is our NPFL that's been identified and and then isolate it and then we basically pull that up through this this leaf that you make on a lateral on a medial aspect of the patella to basically imbricate or reef this NPFL up and I still will do this along with my NPFL reconstruction so we still respect their anatomy and then once it's all done we want to advance the VMO down if they have a high riding VMO so this is introp so we can see our tunnels for our suture anchors here again these are all suture anchors you can see the top of the patella is there so this is high in the patella these are our two limbs of our our hamster our hamstring graft and then this is our NPF our native NPFL here and now we've gotten everything repaired back down our tails of our NPFL we got our imbricated NPFL back in place in our VMO which is pulled distally so these are the before pictures so he's got some tilt we're looking from proximal to distal and his groove is not terrible so so I think someone who would do well without any additional procedures and this is after our NPFL reconstruction lateral lengthening VMO advancement and our patellar tendon shortening and so when he's in full extension he's almost engaged in the trochlea he's just above it and I think that's important so he's no longer riding on that anterior cortex of the femur so what are the results with NPFL reconstruction so I think in most surgeons hands patients do very well so low redislocation rate you know some people report fractures and usually that's with trans patellar tunnels so it's a rare complication but overall patients do very well and what's new in the literature so quick rapid-fire stuff here we'll spend a little bit of time here so we look at isolated NPFL and you just ignore all the other factors so TTTG, patella alta, you know trochlear dysplasia all that stuff so these authors in Journal of Knee Surgery so their patient population so patients with TTTG over 20 versus TTTG less than 20 no difference in tegner leishon high grade dysplasia versus low grade no difference CDI so patella alta versus no patella alta no different femoral anaversion above 30 lower than 30 no difference. Beth Schubenstein and others also in this recent study another great study because they really did more than just a tegner leishon they did a lot of patient reported outcome measures here and they in their population greater than so one-fifth of their patients had a TTTG over 20 over a third of their patients had a CDI greater than 1.2 they had one out of 72 patients re-dislocate they had all improved outcome scores so I think these are great studies the one caveat is they were short shorter term follow-up and I'm sure Beth is following these patients out and hopefully we'll continue to present on this but I really like these studies I thought they were fairly well done. Laurie Heimstra up in Canada looked at the risk of pathoanatomy with respect to outcomes after NPFL reconstruction and again their study population a lot of high-grade dysplasia TTTG higher and you know small quarter of their patients CDI high and over a fifth of their patients they found that all their patients got better and actually their predictors of poor outcome were patient with bilateral symptoms patient whose femoral tunnels were placed more than one centimeter away from shadows point and patients who were increased age at the time of their first dislocation so decreased quality of life scores for us for those groups and then another study looking at biting scales we worry about earlier Stan Lowe's and Marfan's and whatnot so patients with the positive biting score they found that there was no correlation with outcomes and so you know so these studies all sort of looked at really you know for the non-complex patellofemoral instability patient NPFL reconstruction and you know adding some other things whether that be lateral retinacular lengthening or shortening those patients can do well this was the last of the studies that was published recently looking at predictive factors for failure and I really like this study so a quarter of their patients had a J sign trochlear dysplasia was present in most of these patients which is common in our in our in our patients CDI was high on average and the TTTG was not overly high but they did have some patients with a high TTTG and really their big risk factors in the patients who failed were they had a high CDI so patella alta and a pre-op J sign so those and and when you look at patella alta and J sign those things are probably linked meaning that patients who have a high-riding patella are more likely to have a J sign so what are the take-home from these articles so you know if you're if you're doing a good NPFL you're putting the tunnels where they're supposed to be and they have good rehab most of your patients are gonna do pretty well and have a low redislocation rates they're gonna have a high return to sport but certainly you want to proceed with caution and patients who have a severe patella alta so CDI which is greater than 1.3 and then high-grade trochlear dysplasia and again beware of the patient with the J sign so what have I learned over the years this again as I mentioned a very successful procedure I think return to play is very high so I think patients who are athletes and have instability and they ultimately end up having surgery I think they have a high rate of return to play to to what they were doing before and you know I'm gonna continue to jinx myself but you know I've seen no revisions of my own you know my ACL failures find me my rotator cuff and shoulder instability failures have found me but I have not had any of my patella formal instability patients come back and with recurrent dislocations I've taken care of others people revisions just none of my own yet I know it's gonna happen but but also reason why I love taking care of these patients because I think we have a pretty good approach to managing these and really looking at all the things that are gonna help increase success so so what's next you say well if it ain't broke don't fix it you know if you had asked me five years ago I have ever done a trochlear plastic I would say absolutely not you know there's no way I would ever do that procedure but after you know starting to see you know some more more and more complex patients that are now finding me in my practice and then a couple years ago I had the great honor of doing the traveling fellowship in Europe two years ago and I got to meet David DeJure and see his operating room in Lyon really opened my eyes and this was practice changing and so you know I do think there's roles for other things in the patella femoral instability patients trochlear plastic is still good and select patients this is some of our current research looking at you know different morphology of the distal femur and so trochlear plastic for me is important for revisions and is your D trochlear and Dave Dedeck is gonna go over that stuff tomorrow or yeah tomorrow but you know this is where I've really expanded so you know I've gone from you know the Fulgorson lateral release and residency to now you know expanding to all these you know different things an important thing if you're gonna go out and you're truly gonna take care of patients with the patella femoral issues you got to have a lot of stuff in your tool belt and it's not hard but you do have to spend some time you have to you know get the right imaging and really figure out you know how exactly to approach these patients to get some good success and and as with just about anything that we do you don't want to just be a one-trick pony because eventually you'll be a one you'll be a dinosaur you'll be yesterday's news so my last lesson is never stop learning and keep on growing I think my horizons continue to broaden because I do a lot of research and I do a lot of reading because it's something that I really want to be good at because again is what I've sort of decided you guys are gonna be my career path yeah I'm involved in one of you know one of favorite things I do is the International Patella Femoral Study Group this is our last meeting that was in Banff back in the fall I have some great mentors and friends that's me in the back Dave Dedek is there and then Seth Sherman who's also going to be talking is right there up in front row and center where he belongs because he's one of the big patella femoral ballers in the country but it's been great you know learning more and more and it's been educating me and so I've opened my mind to a lot of different things and I continue to learn so one of our key takeaways so avoid lateral release so if you don't learn anything from this talk the isolated lateral release for the patient with patella femoral instability just just don't so TTO is very rarely needed Seth Sherman is gonna give us some guidance on that tomorrow it is part of my practice but again it will kind of outline when we should be doing that you really want to have a deep understanding what the normal and pathologic anatomy is so anatomic NPFL reconstruction is is important high grade dysplasia trochleoplasty certainly a lot of research a lot of you know a lot of doors are still open with respect to that Dave Dedek will be talking about that tomorrow be aware of the J sign you see that you make sure you want to address that and then in patient with severe patella alta either patella shortening or you want to distillize with the TTL so that should be it and we can open up things for questions again thanks mark for let me be a part of this and hopefully you have some good discussion here Luteal this is Dave Dedek enjoyed that talk that was fantastic I wonder if I could open just with a comment and then a question yes sir one comment would be to kind of help people in the OR troubleshoot their femoral tunnel position because I think you understand that is the key part of your NPFL reconstruction is putting that in the right place and if they watch their graft behavior as the knee flexes the the phrase I help people remember this by is high and tight low and loose so as they flex the knee if it's tighter than their frontal position is probably too high and proximal and if it gets looser it's probably too low or too distal so high and tight low and loose as you watch the knee flex and watch your graft behavior can be helpful so the other question I had I had for you is to frame for these these these fellows how often are you doing a lateral lengthening in conjunction with an NPFL reconstruction so I'm a little aggressive with the lateral lengthening and to be honest in my practice I probably will do that I would say nine out of ten knees so I do it quite often so I think a lot of these patients have tilt and even if I do just a little yeah I will do that in most of the knees that I see it's rare that I uh I don't do it so I'm a little bit more aggressive with addressing the lateral side the tool access Sherman great talk can you follow up on that just a little bit more for me and for everybody are you assessing that till preoperative interrupt through your super medial portal and then are you using your central NPFL incision to do a lateral lengthening you're not doing it arthroscopically correct correct so yeah so my my incision is a midline incision so usually if I'm gonna do a lateral lengthening I will and that's all based on so preoperative imaging when I have them in clinic I try to tilt their patella so I grab their patella I think everybody can see me here so I grab their patella I try to tilt it up and if you know they're tight so I kind of get them to the center of the groove and I try to tilt them up and if they don't come up to at least horizontal or parallel to the floor then that to me that means they have a tight lateral retinaculum and and that's sort of my pre-op assessment I look at their imaging so their axial images on the MRI I don't get dynamic CT scans on everyone I probably am doing less and less of that than I did you know five years ago because I don't think they're needed I think you get a lot of information from your MRI and then introp I do that again in the operating room once they're relaxed we try to tilt them up yeah I think you can assess that when you're looking from the superior medial portal also so I use all those things when I when I'm assessing these patients introp so I always start with the diagnostic scopes I'm so scoping is always part of my um I know some people don't scope before they do these so I always scope as part of the procedure the tool I got very nervous when you were doing that patellar shortening when I when I've got to tell her all time usually feel more confident about doing a tibial tubercle osteotomy and distal icing trying to get bone-to-bone fixation I you know I've seen some disasters of people trying to cut the patella tendon and and doing other things with it to either lengthen or shorten it and I've usually had to bail out some bad stuff I mean talk to us a little bit about that shortening procedure because I know I saw Jack Andrush's paper on that but I just I got very nervous yeah and it's and it's something that you know not a lot in the patella femoral joint scares me so when you're undermining cartilage for a trochleoplasty like I don't get the same kind of sphincter tone as I get when I'm cutting through the patellar tendon so yeah we've done you know a few of these and you know it's something that I think the indication for it or it's not it's not like most of the patients that we see and every single time we do this I worry tremendously and it's something that you know go very slow on but also realize that you know when you take care a lot of patellar tendon ruptures and we know what sometimes that tendon can look like look like mop ends I think it's an area that's pretty well vascularized and it kind of begs to heal and so I think actually cutting through the layers of the patella it's not really that difficult you know I make sure I undermine behind it so I sweep the fat pad off an area that I'm you know trying to get in between the patella so I can assess so I can look from the side and see exactly how thick I'm getting through the patella or how thin I'm getting through the patellar tendon and then you know just go nice and slow as you do this and it actually happens you know fairly easily I think the hard part with this is the post-operative rehabilitation you have to be very careful with your physical therapist as to when you move these patients these are ones that I keep them kind of locked in extension the first couple weeks and we don't even start any kind of flexion right away if they're severely high and you expect that they're gonna have a lot of tension in this after you repair it then you may have to actually lengthen me the quadriceps and this is more so in the patient who has congenital dislocation sometimes you have to lengthen the VM be the vastus lateralis you have to lengthen the quad tendon just so they don't end up with the overly tight extension mechanism but for somebody like this that we're just we are reefing just a centimeter you know it's an easy technique to perform I think you before you do it if you have the ability to do that in the lab first before you do that in your first patient I would highly recommend it obviously got to see it during fellowship and I've gotten to do it in the lab and you know so I think it's a little bit easier to do but I think the key points are really go slow with this have a sharp knife when you do it and then you got to be very careful with the post-operative rehab so these are ones that I reach out personally to the physical therapists and say we can't just start jacking on their knee right away and really take things slowly this first first month after surgery we have we have a few questions here one that goes along with this question does this reefing procedure elongate over time it can absolutely so we are in the process of looking at some of our long-term results mainly mostly their jacket Jack Andrews patients and you know you know we get cereal extra cereal x-rays and we measure the CDI all on the way and some of these patients will stretch out over time I think for the patients who are not obese and the patients who you take slowly through their physical therapy, I think they maintain, they mostly maintain their shortening. Tori Perry was asking, thank you for the sex on talk, Dr. Farrow. In chronic dislocators, what level of PFJ chondral damage is acceptable in patients who treat operatively? So, you know, that's a great question. And I think those of us who see a lot of patella femoral instability know that a lot of these patients are happier from a chondral standpoint, and we're not talking about the acute, you know, osteochondral defect from the dislocation episode, but a lot of these patients who have been subluxating since they were seven, eight, nine years old, and they're seeing you at 14, I think, you know, some chondrosis in those knees, the prevalence of that is very high. And those patients, they tend not to have a ton of pain when they get in to see you, and you stick a scope in, they have all this chondrosis, and you say, good gosh. And it's, you know, mainly like on the patellar side, because they've been basically edge loading on the lateral aspect of the trochlea. And I think some of these patients, once they're no longer edge loading, and you actually get them back into the groove, you know, I haven't had many of those patients come back and say, well, I'm stable, but my knee still hurts. You know, I think those patients generally are happier without having to do anything from a chondro standpoint. You know, if they have loose flaps and stuff, you know, obviously chondroplasty, but that's also something that if they're not necessarily complaining the pain, and they have chondrosis, don't go taking a shaver to that, because you can wake up a sleeping bear. And so if they're not complaining the pain, and their main issue is stability, stabilize the knee, and leave the cartilage alone, no matter how bad it looks. And I think most of those patients will be pretty happy. Cool. Steve Cohen from Philly. Latul, I don't, but some surgeons recommend not using fluoro for the MPFL reconstructions. I use it in all reconstructions. But what are your thoughts on intra-out fluoro? That's a great question from my standpoint, but I don't know how you could do this without fluoro. But Latul, what's your? Yeah. Yeah. Great question, Steve. Thanks for joining. So yeah, you know, like I mentioned, early in my career, you know, again, this is sort of me sort of being arrogant, probably, you know, again, I had done a lot of research, and you understood the anatomy. And basically, I would palpate the adductor tubercle, I palpate the medial condyle, and I kind of will put that where I thought it should go, you know, based on some of our anatomic findings. And again, you know, it's probably been six or seven years ago, I got a post-op x-ray, and that tunnel was just like somewhere just like it was a bad, it was a bad looking tunnel. And even though the patient did great, from that point on, I've always used fluoro and drop doesn't take very long. I do use a large C arm just because it's a little bit easier to maneuver compared to the mini C arm. And, and literally, you know, the tech comes in, I get my starting point, we draw, we find our starting point. So it's not a whole lot of x-ray that you're giving to the patient and everyone else in the room. So I think it's so quick that, you know, I wouldn't ever recommend people do it without fluoro. So I am a big proponent of shadows, shadows point. And so that's the and that's the way I approach it now. The tool, can I comment on that? Yeah. Yeah, I think there's nuance here. That's so important for the fellows. I mean, the order of operations, and we all may do it a little different. But we all think about fluoroscopy, anatomy, and isometry in some order. So for me, I use shadows point with fluoro, large fluoro, just so I can get my incision. I use anatomy for my patella area to put my suture anchors like you do. And then I check isometry or anisometry the same way you do. And I will not drill my femur until I'm happy either isometric or loose inflection. So I think there's variations of all those themes. But, you know, that works for me so that I can get it right. And I'd much rather be too loose than too tight. And I think you elucidated that really well. Yeah, absolutely. Here's, I think, related to that patellar reefing, patellar tendon reefing, Christian says, do you use any kind of device like wire to protect patellar tendon when you're doing that shortening? Yeah, another great question, Christian. Thanks for that question. You know, I don't. So short question is I don't. I thought about it, whether you use a wire or use Marceline tape, Marceline tape for some of the old timers or use, you know, some other, you know, soft or some other suture type construct. Certainly that would help protect the tendon. You know, I always worry about stress shielding repairs and getting collagen laid down correctly. You know, certainly you can potentially use it as a check rain. But I do always worry about whether, you know, using anything to protect that can actually hinder your collagen formation. And it's just anecdotal. But I know I haven't. I don't believe Jack Andrews does either. You know, I think the main thing is just protecting them, you know, post-op. Here's a question from Jay Wu. Are you more aggressive about performing a TTO if there is more significant patellar chondral wear? Great question. You know, I think, unfortunately, a lot of the wear patterns that I see in these patients, you know, they're not always amenable just to just straight up doing your AMSI triad or you're focused on osteotomy. A lot of these patients may have more diffused disease. And I know that some of the literature shows that even with diffused disease, osteotomy can still help you. And so I still, you know, again, will lean back on their symptoms and, you know, what they're malalignment is. Now, if they're borderline, they're 18 millimeters on their TTTG, and they have some lateral facet chondrosis, and they're complaining of some pain in addition to their instability, I think that's the patient, even though they're kind of borderline TTTG, I think that's the patient that doing a AMSI triad or focusing along with your stabilization, you can kind of set you up for success. But, you know, again, if they're not complaining the pain and their rotatory alignment is not severe, I still will just stick to the science and still will just do the MPFL, their balancing and whatnot. So here's two questions related to your lateral retinacular lengthening. First one from James is, do you do the lateral retinacular lengthening before or after the MPFL recon and does it matter? I think, yeah, I always do the lateral I think, yeah, I always do it before. So I love Seth's comment about order of operations. And for me, you know, I'm in the operating room, you know, we get the patient set up, and normally I use a leg holder for all my procedures, and I drop the end of the table. These patients I do in the supine position, I use a stress post so we can move their leg wherever it needs to go, and also makes it a little bit easier for Florida to get in. I don't drop the foot of the bed. I make a little platform, a non-sterile platform to sit the leg on, because that makes it a little bit easier for the lateral x-ray. And then, so since I do autograft for all my cases, I have a PA. So, you know, I harvest hamstrings, and while my PA is preparing the graft, I will close the harvest incision, will scope the knee, and then once we're done scoping, get all our diagnostic stuff, then I make my anterior incision. And usually, even though it's a straight midline incision, I can usually make the incision just the size of the actual patella, and I can work on my NPFL and lateral retinaculum through those incisions. And so I will always do the lateral lengthening first, because I think it won't hurt you when it comes to doing your NPFL, but certainly allows your patella then to go medial, and then I think that helps with tensioning or fixing your NPFL reconstruction. And then once we lengthen the lateral retinaculum and repair it in our lengthened position, then I go over to the medial side. And I do make a small incision now down at the NPFL attachment site, so that's why I think I can get away with a slightly smaller incision anteriorly. And it's just big enough to get my, and it's gotten smaller over the years, and so it's just, it's now big enough just to get my ramer in to drill my tunnel. So Alexander Brown asks, and from what superior to inferior spots on the lateral retinaculum are you doing your lengthening? Pretty much from the tibial plateau all the way up till you see kind of, at some point you see vasus lateralis peeking through. So once you get to that muscle belly of the vasus lateralis, then you know you've released enough. And even in the world of when we were just doing arthroscopic lateral release, that was the key. You really had to do a pretty long, if you really wanted to truly release everything, is if you just release in the area of the patella, it's not enough. There's some bands that go down from the patella to the tibial plateau that you have to be through those. And you know, obviously as you get closer and closer down to the actual tibia, the lateral retinaculum begins to peter out a little bit, and the capsule for sure starts to peter out a little bit. But so it's pretty, you know, extensive, so you want to make sure you're deep enough. And as you sort of release, especially the capsular portion of it, you know, I keep testing the patella for tilt, because that allows me to know that I've gotten everything released. That's a great question. And then Shamu asks, how are you checking your isometry with your MPFL reconstruction technique, and also is there a role for MPFL repair in more avulsion type of injuries? So I'll start with the repair, repair slash reefing. I do think there is a role for that. I don't use it in a patient who's been, you know, multiple dislocator, who's been dislocating since they were, you know, sort of preteen. You know, it's not a part of my practice, but the patient who comes in, and we see some subsets of patients who have patella instability, and they're kind of subluxating more than they are dislocating. And I think those patients do very well with just a reefing. But in my opinion, I think that MPFL tissue is pretty crappy for the most part. And that's why part of the reason why they failed. And so I think sort of reefing or imbricating crappy tissue in my hands may not be the best method. But, you know, certainly, you know, if you talk about doing a, truly, if they're off the femur, or off the patella, there's a piece of bone involved, and they have a, you know, cartilage fragment or something, and you're taking them to the operating room acutely, I think you can make an argument for repairing that back down. You know, those in my practice are few and far between. So it's not something that I'm doing very often. And then what was the other part of the question? Are you checking isometry for with your MPFL reconstruction? How are you checking it? Yeah, so different ways you can check the isometry, you can put your guide pin in. And once your guide pin is in place, you know, you can put some suture on that and and then take it through a range of motion and kind of see how the suture lengthens or not. You can also do that just with a, you know, a hemostat through your at the at the attachment point where you think you're going to drill your tunnel. And that's a good way to check isometry. You know, do I do that for every MPFL? I don't, to be honest, you know, I think a lot of time I will rely on Schottel's point. And, and based on once we have our pin in place, and based on what, you know, sort of the way I think the isometry is going to be. So I think if we're tightening inflection, which hopefully we're not, you know, I will be more likely to fix the graft and a little bit loose in position just so we don't capture the knee. I think that's a key point is about MPFL problems is capturing the knee and over overtightening. I mean, I think that that's something we need to be very careful. I know we got a, we got a guest, a guest question from Adam Yankee. So, up on. Sorry. Can you hear me? Okay. Yep. So the tool that was awesome. Great review and excellent summary of the literature. I learned something every time I hear any of you guys talk about this. So great job. And I was just curious when you talk about the location of the footprint relative to the growth plate, I've done a fair amount of scholarly and mature patients and I agree I do distal and anterior with the tunnel and I still do trans-osseous and avoid the growth plate. But I did have one recently that I checked probably five times in the OR and I swear the adductor tubercle was proximal to the growth plate, even on coronal views. I'm wondering if you've ever run into that and how you change your reconstruction technique or if you've ever found that the growth plate's pushing you out real estate wise. Yeah. You know, I've not ever seen that where we've had to put anything proximally. I think still, you know, Shiloh's technique is still kind of my workhorse, even in that situation. And I think a lot of what Shiloh's technique is based on is based on some of the isometry of what the graft is doing, you know, in these. And obviously isometry can be a little tricky depending on how some of these needs are shaped. You know, I don't think, you know, with the femoral anatomy, I think Shiloh's point can have some issues and some of these patients just have some really bad anatomy. And I've had some instances where, you know, once the condyles are kind of superimposed and we're doing Shiloh's point, it's not necessarily where I think it should be based on the anatomy. But a lot of times I still will stay true to Shiloh's technique and I still will try to get this distal to the growth plate, you know, just because, you know, I do worry about the growth of rest. And so I have not run into that often. You know, obviously it's not a huge, huge, you know, I don't do as many kids as I do adults. Because, you know, we have a pediatric sports medicine person here, but, you know, I will do all the kids, skeletal immature kids that make it my way. I'm not necessarily seeing it yet. Thank you. You know what? We have a guest patella femoral guy here. Don Fission is, who has done a lot of work on patellar dislocations. And actually, I'll ask, I mean, because the tool you use suture anchors. Don, if I'm not mistaken, you do drill holes through the co, through the anterior part, from medial to anterior on the patella, not all the way through medial to lateral. Is that right? Yes. Can you hear me Mark? Yeah. Seth, before I ask you that question, Don, Seth, what do you do? You use anchors too, right? Yes. Small suture anchor here. Dave? I use drill holes, two anteriorly directed drill holes, 3.2 millimeters and loop a gracilis graft through it. But not through and through. Not through and through. And I don't do, I don't do through and through too. But Don, do you want to comment on anchors maybe versus the drill holes on? Well, I use the drill holes because I can adjust the tension. I fix on the femur first and the patella last, so I can adjust tension. And by not using anchors and sewing the graft to itself, I can run the knee through a range of motion. And if it's over tight or not tight enough, I just take the sutures out and re-suture. I can't do that if I've done, you know, fixed with anchors. But, but, you know, there's, I think that drilling through and through across the patella runs the risk of either you're going to be too far anterior, too far superficial, in which case you can violate the tension trabeculae, that's where you get fractures, or you'll go too deep and you hit articular cartilage on the lateral facet. So I think staying on the medial side is a good idea, whether you do it in a single drill hole or I just basically do two corticotomies with the drill. I just drill through the cortex and then complete the tunnels. They're kind of L-shaped or V-shaped tunnels that come out the anterior medial third of the patella. Yeah. And that's kind of the approach I do, because I also, it sounds like I think Seth and you tension off the femoral side, right, in the tool? Yeah. No, no, no. I fix on the femur, so I put a blind socket on the femur. I use a biotinodesis screw or a peak biotinodesis screw there, and then I put my, I tie the, so this is kind of like Tony Sheps's technique on the patella, so I put anchors there and I tie it in to the patella. So I do the patella last also. I do exactly what the tool does, so set the resting length on the patella side. And Dave, you did it again. I tension on the femur side, so yeah, yeah, I put the pin there. I check, I check my, my graft behavior, and then I'm going to tension on the femoral side with a single interference screw. I did the same as Dave. Interesting. Very cool. All right. The tool, there's a, we got only a little bit left sometimes. Somebody's, somebody who's not somebody's, somebody whose name is 125462 asks, what is your femoral tunnel diameter size, and have you had any growth plate complications? So no growth plate complications yet, and typically with a doubled over, and I think one of the benefits of using Autograph Semi-T, for whatever reason, Allograft Semi-Ts tend to be a lot bigger, in my opinion, but with the Autograph Semi-T, typically, we're sliding through a seven millimeter sizer, so I'll drill a seven and a half millimeter tunnel, and I usually put a seven, you know, the Arthrex Biotinidesis screw is, I use a peak screw. I don't like using absorbable screws here, but I use a peak screw, and that usually is a a seven by 23 screw that I use, so seven millimeter graft, seven and a half millimeter tunnel to get everything fed in there, and then the screw goes in with that, and I, you know, I'm a big dude. I will yank on that pretty good, and the fixation is pretty solid with that. All right, the last question, Alexander Brown, at the point, at the moment of final fixation of the MPFL reconstruction with the hamstring autograft, how are you ensuring the proper tightness or looseness of the autograft? So, you know, taking it through a range of motion, and you can see based on where your anchors are placed, you can actually mark the graft, and so you can put the graft that, whether you put it in an extension, so usually I don't put an extension. I put it about 30 degrees, but you can mark it at that point. You can kind of hold the patella in the groove and then flex the knee. You can actually see what the graft is doing, whether those ink marks are moving, you know, posteriorly from the patella or they're moving anteriorly as you're going through flexion, so based on that, and you know, luckily, I think most of the time, our isometry is pretty good, but based on that, if you feel like it's going to be too tight or if it's tightening in flexion, you know, it's obviously too late to to move your femoral tunnel, but you can then, as Seth said, it's better to be too loose and too tight, because if you are too tight, chances are the patient, they're going to get their motion, but it's going to be at the, at the sacrifice of your stability, and they're going to stretch their graft out or pull out their fixation. All right, that was phenomenal. Anybody, any last comments from our patella femoral experts that are, that are on the, anybody, anybody want to actually, other than Latul and Seth, admit that they're a patella femoral expert? But any, any other questions, if not, or comments? Latul, that was, that was phenomenal, man. Thank you so much. Really appreciate it. I know I've gotten some comments through here with all the fellows and residents who've been on it, also really appreciated it, so outstanding. We look forward to hearing Dave Dedick tomorrow talking about the trochleoplasties in his approach, and then, and then the day after, Seth Sherman about the tuberculosteotomy, so. And that's my email address. If anyone wants those articles on the NPFL, sorry, the lateral lengthening, as well as the patellar tendon imbrication, just email me, I can send those to you. And then, also, there was a comment here, a question about, this is going to be on the learning management system for the AOSSM. This week's will be on starting next week, so I'll see if I can find out what that link is, but it's going to be through the AOSSM learning management system, through their playbook, their AOSSM playbook, they call it. So, thank you all very much. Look forward, tomorrow is 3 p.m. Pacific, 6 p.m. Eastern Standard Time. I appreciate everybody's participation. So, thank you all very much, and Latul, thank you so much, man. Appreciate it. That was fun. Thank you. All right. Take care, everybody.

patellofemoral instability

anatomic reconstruction

medial patellofemoral ligament

trochlear dysplasia

patella alta

lateral retinacular lengthening

chondrosis

fluoroscopy

graft placement

surgical techniques