We have about five minutes now for Q&A, so please use the app on your cell phone to ask any questions of our speakers. I guess, Dr. Mansouri, a couple of questions came your way. First of all, can you discuss the impact of rotation on slope X-rays, and then secondly, with there being such a difference in slope postoperatively, how do you measure postoperative radiographs? Do you get a full-length X-ray in the recovery room, or how do you follow them postoperatively? Great. So, the first question is rotation definitely can affect slope, and we try to get our, we use the lateral femoral and the medial femoral condyles to try to have them less than five millimeters of lacking overlap, to try to get a true lateral. So, it's mainly based on the femur, and then postoperatively, I will use the long-standing lateral initial X-ray, and then from that line that I have, I will zoom in to basically mimic what a short leg lateral looks like, and then where that line appears, I'll use those two points instead of using the central points like you would measure off of a standard short leg film. So, then I can use the same measurement as if it was a long leg without having to repeat long legs. But I typically do get, right now, long-standing lateral and long-standing AP at three months, because we're really trying to be critical of our results, but to follow them clinically, I think getting the long leg initially and monitoring those points is the easiest way to do it. Thank you. All right. The next question will be for Dr. Marconi. Did you use bone for your quad tendons or just soft tissue quad alone? And is there any concern to harvest the bone with a quadriceps graft after a prior BTB? If so, how long should we wait to harvest the bone with the quad after a prior BTB? So, we used free-tendon quadriceps for all cases, so we didn't look at any data for the bone quad ACL. Yeah. So, I guess. Question for Dr. Savner. Do you think ACL repair has a positive or a negative effect on post-traumatic OA? I didn't hear the last part of the question, sorry. Do you think that ACL repair has a positive or negative effect on post-traumatic osteoarthritis? We don't have any data to answer that question so far, but what we do know is that if you harvest a patella tendon graft, you affect patellofemoral kinematics, and patients who've had a BTB graft have a higher incidence of osteoarthritis compared to hamstring tendon grafts. So, I think if we're avoiding donor site morbidity, then perhaps there's some possibility of minimizing the risk of OA. Also, if we're improving the proprioception of the knee by maintaining the remnant and the proprioceptive fibers there, that may also have a role. But this is just hypothetical. We don't have any evidence to support that. Given your differential in age between patients, do you tend to not do repairs in patients under the age of 21 as opposed to- Correct. Yeah. And there's a few reasons for that. Obviously, we've demonstrated, and so have many other authors, including Greg DeFelice, that the failure rate is higher in younger patients. But one of the things that we've learned from doing remnant preservation surgery is that in young patients, that remnant seems to absorb much more quickly than in older patients. And so, there seems to be some biological influence. Maybe the inflammatory environment of the knee is more aggressive in younger patients. That means that remnant has a higher chance of surviving, or rather, a less chance of surviving. Thank you. Okay. And I'm going to put a question to Dr. Pierce. So looking at some of your data, and within using the LAT, do you notice that there is some, I would say, over-constraint of a few millimeters in extension? Does that affect how you're going to look at this from a clinical standpoint? Does that affect? Say that one more time. So looking at your data, you showed that with the LAT, and when they're in full extension, you do over-constraint by a couple millimeters for anterior tibial translation. How do you take that information and translate that to what you're going to do clinically? Great question. Great question. So one thing that I was really excited to see is that we didn't see a lot of over-constraint in internal rotation, but just in that extension for that anterior tibial motion, we don't know if that's going to lead to increased arthritis. And so I think it's something to be aware of as we're deciding on this LAT, the soft tissue procedure. Really, the big question is, are we able to use that soft tissue, less risky procedure to be able to offset some of this bony problem? Really, it's kind of that old age problem in orthopedics where it needs to be a bony correction to get a full correction and protection of that graft. So it's something that we need a lot more information on. I think looking at similar studies, but looking at different lands or different motions where we test the knee will help give us some more of that information too, because we just simulated a slow LAND to create the most clinical applicable situation that we could in the lab. And so I think we have a lot more opportunity to learn with different motions that we see. I guess the last question for Dr. Satan again, how would your patient conversation preoperatively go in regards of ACL repair, a concern that those patients very often know that ACL reconstruction remains kind of the gold standard? It's a little difficult to hit the questions here, but I think you're asking how to explain the advantages and disadvantages of repair versus reconstruction. Yes. And I think what we have demonstrated is that the clinical outcomes are, for the main outcome measures that we typically use to evaluate the outcome of ACL reconstruction are very similar. We have not demonstrated a significant advantage in terms of return to sport. We have demonstrated a significant advantage in terms of hamstring strength at six months, and that's a finding that was also shown in the BEAR study, but that's likely related to the fact that many of our patients had hamstring tendon grafts for their reconstructions. And the other positive finding that we had was that the forgotten joint score was less. I don't think that in itself is a strong reason to justify doing an ACL repair. So I think the indications for ACL repair currently are small, but what our study does show is that there is potential, especially with the trend that we had for earlier return to sport and a higher return to pre-injury level of sport. Those were trends, but our study only had 75 patients in each group, and I think that justifies a further study to investigate those things. Thank you. Great. Thank you.

ACL surgery

rotation on slope X-rays

soft tissue quad tendons

post-traumatic osteoarthritis

ACL repair