All right, so this is a little bit of a daunting 10-minute talk because I think we could spend hours on graph choice, technique, and everything, but I'm going to give you the Cliff Notes version and a little bit of my personal preferences. So I have no disclosures. So why are we talking about this? Why is this important? And so what's really the elephant in the room? And I think for most people, especially those who may not do pediatric sports medicine on a regular basis, it's the physis, and that open physis brings a fear to many people. And why are they fearful of that? Well, this Herodicus study or society survey that was done by Minn-Coker back in 2002 gives us kind of a great reason to have some concern. Out of 140 respondents, about three-quarters of which had experience in pediatric sports medicine, they found 15 growth disturbances from ACL reconstruction. The majority of these related to bony bars resulting in valgus from rigid fixation across the physis, so either screw, staple, pin across the physis, or bone. Another found a large femoral tunnel associated with the bone plug, and another with over-the-top fixation. There were fewer cases of valgus without a bar associated with lateral extra-articular tenodesis, and then a couple cases of limb-length discrepancies. And then fewer cases, but still present on the tibia recurvatum, specifically from fixation adjacent to the tibial tubercle physis. And so studies such as this and others kind of led the way for a lot of non-operative treatment that occurred in the past. And so the old dogma for skeletally immature patients was that we're concerned about potential physeal injury and growth disturbance, and we're going to delay ACL reconstruction until skeletal maturity, and instead we're going to brace you in rehab. The Pluto Study Group recently published a meta-analysis that said, what are the outcomes associated with this? And I think you can guess a lot of these. If you take a 10-year-old boy, and he's ACL deficient, it's like, OK, Johnny, you're not going to run, jump, play, PE, recess. This is not just a kid who plays competitive soccer. This is a kid who jumps down the stairs as a means to go from the kitchen to his bedroom. And so as a result of that, we see significantly higher secondary meniscal injuries, many of which are irreparable, residual knee instability, and lower rates of return to sport. And information such as this has really shifted the paradigm towards surgical treatment of these patients. So age really matters. So the image on the left is a patient that I treated four years ago. It's hard to tell from this picture, but he's 4'11". He's 12 years old. He had a bone age of 12, had an isolated ACL tear and functional instability, plays football. And so I did a FICL sparing ACL reconstruction with IT band autographed. And this is him. He just followed up Tuesday before I left to come out here. He's now 6'1 and 16 years old. So clearly a kid who's grown 14 inches or so since he had his surgery. Definitely not a kid that you would have wanted to cross the growth plate with something rigid in. The other thing is not every 12-year-old or 10-year-old is the same, right? We see 13-year-olds have facial hair. We see 13-year-olds who look like they're eight. And so we really have to look at more than just their chronologic age. We know their activity levels and exposure risks are very different than adults, right? You know, these kids play competitive soccer seven days a week. It's very different from the person who has an office job and enjoys playing some pickup basketball on the weekends. We know from many studies that if you look at ipsilateral graft injury and contralateral ACL tear, that that risk of secondary ACL injury in the first few years after ACL reconstruction is 20-plus percent. So we really want to be thoughtful about what we're doing to minimize the risk of that. So ultimately our goal is to restore knee stability while preserving growth remaining. We have several different techniques to be able to do this. So this is a very generic outline, but I think it kind of highlights the pertinent points here. So one is looking at both physiologic and skeletal age. We'll talk about that a little bit. And then I really divide these patients into three groups. Those are essentially skeletally mature, closed physes or closing physes. Those with less than three years of growth remaining, and then those with more than three years of growth remaining. And for me, I kind of use this division to decide my treatment algorithm. In terms of determining age, I think there's several different ways to do this. If you have the big Grula Compile Atlas, you can pull out that, you know, 250-page text and sort through it and figure it out. I live in the digital age and not in the land of big giant textbooks. And so I have this app on my phone or I have a screenshot of it. And so Ben Hayworth and colleagues had described this back in 2013. Using a shorthand bone age, it basically takes the pertinent radiographic changes off of a left hand to assign a bone age. So this is the one particular for boys. And then Andy Penick and Eric Edmonds published a wonderful MRI bone age. So, you know, in kids, we're not routinely getting left hand bone ages for knee injuries, but we are routinely getting a knee MRI. And so being able to use something we already have to be able to calculate age is nice. And this is a textbook that I had written several years ago, a chapter out of it, but we basically took the Grula Compile growth remaining charts and divided these into kind of three big groups. And so basically in kids with less than one year of growth remaining, if you look at the combined distal, femoral, and proximal tibial fices, they have less than a centimeter of growth remaining. Those with one to three years of growth remaining have about one to five centimeters of growth. And those with more than three years of growth remaining have more than five centimeters of growth. So we use this data to stratify our risk of potential growth injury and therefore our treatment patterns. So a plug for alignment, it really matters. So you don't know what you don't ask, right. So let's see, you see a kid who's a year out from a trans-ficeal ACL reconstruction who let's say is a 14-year-old boy. And you look at him clinically, he's got a little bit of valgus, you get a mechanical axis and he's doing one valgus that's slightly asymmetrical. If you didn't have a pre-op APBLE, you have really no idea if this has evolved as a result of your surgery, if that's what he was at baseline. So getting at baseline is helpful. We know genu-valgum and increased tibial slope contribute to ACL injuries and that provides a comparison and ability to monitor for growth disturbances post-operatively. Make sure that they do have full knee extension when you get it. If you're getting one pre-operatively as some flexion contracture pre-operatively can give you a false sense of valgus alignment. So these are my five kind of key ACL reconstruction principles in the skeletally immature. So skeletal age and growth remaining should really guide our techniques that we choose and we'll talk about those. We should avoid crossing the physis with rigid screws or bone blocks. Certainly we cross the physis with things like suspensory fixation and suture regularly but avoiding screws and bone blocks. Bone tunnel drilling, depending on the patient's age, should be as vertical as possible while most importantly maintaining anatomic graft position. You want to avoid drilling at the periphery of the physis and perichondral ring. That's important as well. And then making sure that you assess for pre-operative limb light discrepancies or angular deformities and then follow them post-operatively. So we'll touch on kind of three broad categories of ACL reconstruction techniques. This is definitely not an exhaustive technique guide for each of these. I just provided some highlights on each. So this is an extra-ficeal reconstruction or over-the-top procedure popularized by Dr. McHaley. And so these are just some pictures here demonstrating that technique, harvesting an IT band autograft and establishing an over-the-top position coming around the lateral femoral condyle, passing the graft through the middle of the knee, and then identifying a position within the tibial footprint and under the intermeniscal ligament and then suturing that on the anterior aspect of the proximal tibia. This obviously avoids the physis altogether, I would tell you. You are close to the proximal tibial physis when you're suturing so you do have to use some care there. There's been biomechanical studies that show us. This is a biomechanically sound construct and results in a stable knee. And overall this has been associated with really great outcomes and many series lower rates of ACL re-injury even than our traditional ACL reconstructions in older adolescents. And no reports of limb length discrepancy or development of angular deformities. All epithelial reconstructions also a way to avoid the physis. There's been numerous described techniques with various drilling and fixation strategies. You see a few examples of that here. These likewise restore the anatomic footprint of the ACL which is really the popularized thought behind these and also been shown to be biomechanically sound. Although the distal femoral physis undulates a fair amount so you do have to be careful with your distal femoral tunnel position to avoid that. And it's not without some complications which have been described in 17 to 48 percent of patients in the literature including premature distal physio closure and the thought behind that being thermal injury related to drilling. Overgrowth in some patients from increased vascularity. And then similar overall rates of graft rupture to what we see in our other surgical techniques in adolescents. Hybrid or partial transfacial so this really just combines the both. The picture here is showing over the top fixation on the femur and then transfacial fixation on the tibia and drilling. This can also be done with the all epiphyseal femur and then transfacial tibial tunnels. The thought being that you avoid drilling transfacial on the femur where there's the greatest amount of growth remaining while drilling a relatively vertical small tunnel on the tibia with less growth remaining. Although Hank Chambers and others have shown us this is not without complications as well especially in patients with significant growth remaining. And then there's really transfacial reconstruction. When I explain this to families I frequently tell them yes we're drilling across the growth plate but we do so in a kind of a fissile respecting manner. And so this can be used in this patient population that's in between you know perhaps not the 10-year-old boy but rather the 14-year-old boy. Typically with a soft tissue graft of eight to nine millimeters you have an anatomic yet slightly more vertical femoral tunnel when you're thinking about your drilling technique for this just to avoid drilling directly horizontal across the distal femoral fissus. And then using suspensory fixation, poster washer, interference screw away from the fissus. And theoretically as I tell families this has a low risk of growth disturbance but we are going to continue to follow you clinically. Terms of graft choice that's kind of the next big topic. I'll cover this quite briefly as there are other talks looking at this. So definitely a soft tissue graft and our category is hamstring or really quad or big to soft tissue grafts. I would caution you please don't use an allograft. And then in terms of bone plugs obviously in the truly skeletally immature patients we're avoiding this. So why not allografts? Many studies show us now significantly increased rates of ACL graft failure in allografts in adolescence. So this is a chart here showing the moon prospective cohort with significantly increased rates of graft failure. So choose an autograft and preferably soft tissue. In terms of which you choose, I think you can't talk about ACL reconstruction right now without talking about quad grafts. So this is some data out of my own institution just looking at the huge rise in evolution in grafts. So the green line represents quad 10 and it's just going 2017 to 22. And so you can basically see almost all of our ACL reconstructions, it's almost 1,000, have all transitioned to quad grafts. We see similar findings at other institutions across the country. Why? We know that the size is good as unlike kind of being a flat structure similar to the patellar tendon it has increased graft volume, it has increased collagen as compared to the patellar tendon. Many anatomic studies have showed us the length is quite reliable and predictable even in our younger patients. It's relatively easy to harvest with minimal graft morbidity as we heard about this morning or earlier this afternoon. Even the quad strength looks quite good at functional testing and with very promising low single-digit failure rates. Also can't do this talk without mentioning LAT again. This could also be an hour-long talk or more. Many people in this room and others have done great work looking at lateral extra-articular procedures. Recently I think the stability trial published in 2020 looking at graft failure rates in under age 25 with hamstrings showed us that there's a huge difference in failure rates with and without LAT. I think that really helped contribute to this kind of swing back towards talking about this. Many are still studying this. The question is who do you do it in and when? Relative indications, and everybody has slight variations on this, include our adolescent population, those that are hyperlaxed, if they have a high-grade pivot shift, they play a high-risk sport, in a revision setting, or certainly possibly depending on your graft choice. I always found it helpful when people present it, it's like, okay, you throw all this information at me and tell me what you actually do. Clinically this is what I do. I get a left-hand bone age, although we've started using more knee MRIs to look at bone ages. If they have less than three years of growth remaining, so for me that's a teenage boy less than 13 years of age, or a girl less than 11 years of age, then they get a Ficeal Sparing ACL Reconstruction. I do this McKaylee technique or over-the-top technique with the IT band autograft. If they have less than three years of growth remaining, so 13 and older boy, 11 year and older girl, I do what I call Ficeal Respecting Transficeal Reconstruction with a quad autograft, and then I add a LET in a revision setting, or if they have 10 or more degrees of hyperextension. Thank you.

ACL reconstruction

pediatric patients

open physis

growth disturbances

surgical treatment