Our first speaker is Adam Anz. He's a surgeon at the Andrews Institute in Gulf Breeze, Florida, and he's going to talk to us on biologic augmentation of ACL reconstruction. All right, thank you, Shane. As a disclosure, I do receive consultant royalty and research support from Arthrex. My royalty is related to meniscus repair and not related to this talk. Also, these studies I'm going to show you were supported with Arthrex at Revive College of Osteopathic Medicine in the state of Florida, which is cut off at the bottom there. This is Mount Everest. Mount Everest first was attempted to be summited in 1921. They did not summit Mount Everest until 1953. That's 31, 32 years for those that are counting at home. Similarly, when we think about orthobiologics as orthopedic surgeons, we tend to want to be at the top of the pyramid. We want to be at the top of Mount Everest without learning what it means to get to the top of the pyramid. This is translational medicine in terms of how you get from base camp up to the top. It involves proving and thinking about principles at the benchtop and the animal study level to test and prove principles, followed by thinking through safety at phase one level, then looking at efficacy with phase two level and reproducibility with phase three. On our campus, we've kind of laser-focused on ACL reconstruction, so I'm going to talk about ACL reconstruction, not necessarily about repair in this space. We all have concepts and ideas that we love to improve graft incorporation and ligamentization. Ligamentization is a variable process. It can take anywhere from three months out to 12 months out to 36 months based upon human models. We think about base camp. Base camp is preclinical animal study and benchtop study. There's plenty out there to base other study upon, and that's what we did. We looked through all of the clinical study and determined that base camp had always been well-established. Some of the principles, many benchtop studies have looked at the stump tissue and found that there's resident cells within those cells that caught our eye, and many of the animal studies suggest that you will need all three, scaffold, cell, and signal for this to be effective. This study from 2013 with Mifuni really caught our eyes. We then looked systematically at the literature. From a PRP standpoint, here is the best systematic review that we found to date. In 2019, it was published in Arthroscopy Looking with PRISMA Guidelines. They found 13 studies involving 756 patients, and their conclusion was based upon level one evidence. You could not support the use of augmenting reconstruction with PRP. Similarly, we thought about cellular therapies and did a systematic review looking at what all was out there in the literature from a clinical study standpoint. We used PRISMA Guidelines. We only found four studies that you could really include, two randomized studies, a cohort studies, and a case series. There are variable techniques involved, and our conclusion was that at this point cellular therapies are not evidence-based to augment ACL reconstruction. Along the way, we were also looking at a number of different experiments to think through. First, how would we grade our ACL reconstructions? So, we did a study looking at 3T and 7T tesla MRIs. We then also were looking at what tissues are available at the point of care and found that the effusion fluid has cells within it that can be prepared at the point of care. And we also went into our cadaver lab and thought about technique development and what was the most reproducible technique development that we could use. Our first go at it, and this is BioACL 1.0, was this technique. We want to do bone marrow aspirate, then concentrate it, then have a scaffold, and we looked at amnion wrap as our scaffold, and then implant and then inject our concentrated bone marrow aspirate under it. So, in terms of wrapping our graft, what we found is that reproducibly we could anchor this at each end. We then can wrap it one or two to three times, and then once we had it wrapped, we could seal it with a cerclod stitch at each end, and then a running baseball suture along the way. And this created a nice watertight cell, pardon the pun. Implantation was surprisingly easy. For our patellar tendon grafts, our bone block would protect it. We had no pull-offs with our patellar tendon autografts. We also found that with all inside techniques with hamstrings, we reproducibly could get the end there without the tissue pulling off. We would then dry the joint. We had a sump needle for this purpose, and then a 22-gauge needle we could reproducibly nicely inject our cell. So, this was our bio-ACL technique, and we sought to study it with two different ways. First, we were going to do a case series of autograft. That's kind of our first trek up to Camp 1. Also, a pilot randomized controlled trial. That's kind of our first trek up to Camp 2. We had MRI and PRO outcomes at 3, 6, 9, 12, and 24 months, and then MRIs with T2 mapping and volume. So, this was our first study that we did, and subsequently thereafter, we did another trek up to Camp 1 with allograft as well. Here's the results from our first trek up to Camp 1. BTB autograft case series. Ten patients enrolled, no infections. We had three additional operations, and these were Dr. Andrews' patients, so they were either collegiate or NFL athletes. One worsening chondral defect at one year. One re-tear in a collegiate wide receiver who had returned to play at six months within SEC competition, and then another revision in an SEC wide receiver at three years. In our randomized controlled trial, we had 40 patients, 20 hamstrings, 20 BTB autografts. From a safety standpoint, we had no infections, and we had one additional operation, which was a cyclops lesion in the BTB control group. With efficacy, we found no difference in the PROs and no statistical difference in the MRI measures. Now, this is a pilot randomized controlled trial that was underpowered. So, our conclusion, though, was that intervention did not result in improvement graft maturation. We published this in OJSM in 2023. Compelling was when we looked at the T2 star values. At every time point, the mean T2 values were as lower for the intervention group, suggesting more collagen-based structure. This was true not only for our patellar tendon autografts, but also for our hamstring autografts as well. The green line was our normative values that we had established from our 3T and 7T studies. So, we found that this was more dense than the normative ACL. In terms of our case series in allograft, or our second trek up to camp one, if you will, we had 10 patients enrolled from a safety standpoint. We had no infections and no additional operations. In terms of the T2 star values, what was very compelling is that they were the lowest when you compared them with all hamstring cohorts at every single time point. So, back to base camp. So, this made us reload and rethink. We went back down the mountain, if you will. We wanted to think about, we were moving the needle in terms of T2 values, but the expense had to be considered. And we really, really wanted to go with autograft. So, that's led us to another set of basic science studies. This one looking at the stump, the fat pad, the notch debris, all these materials that are just disposed of at the time of ACL reconstruction. We know that we can gather them with this filter device. Do they remain viable when you gather them with this filter device? And how many cells per tissues do you have? So, we looked at this in our lab looking at different proliferative potentials. And what we found is that the stump and the fat pad have the most proliferative potential. And of course, you can push cells from these tissues to all three cell lineages, which is what we would expect. But the tissues from one specific sort want to become that tissue. So, stump cells really kind of want to become stump cells again. And bone cells kind of really want to become bone cells again. We published this this year in ASMR. We also then, in our cadaver lab, thought about this waste tissue. Could we mix it with autologous thrombin and then reproducibly get a sheet of tissue that could protect our grafts? We found this consistently inconsistent. So, two out of the 10 times, we could create this nice sheet. But it is inconsistent just due to human variation to consistently get this from those autologous tissues. And then when you try to deliver that, it turns into this. It kind of all falls apart when you try. So, we scrapped this idea. We've led this to our second trek up the mountain. We have a randomized control trial underway where we're harvesting predominantly the ACL stump tissue. And then on the back table, we're preparing it with minimal manipulation at the point of care. And then we're injecting it into our grafts, which is giving us more robust grafts in terms of size. This is a study with patellar tendon autografts. And we've enrolled 15 to 50 at date. And we're looking at their results at one year of 10 of these. And from a safety standpoint, we've only had one cyclops lesion in the intervention group. So, in conclusion, what we learned along the way, at the base camp level, stump and fat pad have viable cells that when you collect them at the point of care with a filtered device, they remain viable. And when you minimally manipulate them with certain processes, they remain viable. And autologous thrombin with the idea of creating a nice sheath, that just fell apart, pardon the pun, in literal. When we learned our camp one lessons, Bio-ACL technique 1.0 was safe. One thing that was dangerous is the stem cell hype, because both of those athletes admitted that they were sprinting at six weeks, because they felt they had a magical ACL. And so, consider that when we consider what happened there. The camp two lessons, Bio-ACL technique 1.0 was safe. And I think we moved the needle a little bit in terms of T2 values. And we're using all these lessons that we've learned along the way for another trek up the mountain. And I'll let you know how it goes. Thank you for your attention.

ACL reconstruction

biologic augmentation

Bio-ACL technique

graft maturation

cellular therapies

biological augmentation

translational medicine

PRP