All righty, so you guys are sticking it out for the last ICL for this afternoon. So I've been tasked with talking about optimizing ACL reconstruction in terms of that BTV and hamstring are the gold standard. So I think I have the easy part of the talk. The question is whether you believe these guys are going to talk about quad. So all right. So not much to get to talk about. I mean, we know everything about ACLs in terms of the incidents. Certainly over the years it's becoming a higher incident of ACL tears and with, and these are just kind of the numbers that we think about in terms of like, you know, in the U.S. we have about 43 patients per 100,000 that do get ACL tears, and then within our athletic populations we know that that number kind of goes up. Makes sense, right? If you're going to go stress out your knee, chances are you're going to tear an ACL. So with the rate of ACL reconstructions has also gone up. So if you think about with Title IX happening, at least in this country, in the 1970s, female participation in sports was about 3%, and then it jumped up to about 33%. The latest numbers I got, I could only find the literature from 2006, so it looks like there's probably, we need another paper at some point, looking at high school female population, we're looking at 3 million patients, 3 million females, and we know that there's a higher increase of four to six times increased risk of tears in women compared to men. So then the question is how do we optimize these ACL reconstructions? So when we talk about graft choices, so I guess if you think about this ICL kind of later down the road, we're also going to be talking about maybe bare techniques and repair techniques of the ACL, but for now we're talking about ACL reconstructions. So looking at autograft versus allograft, and really the choices that we have are looking at BTB, hamstring, and quadriceps. That's probably what's most dedicated within the literature. And so when you look at kind of what the native ACL strength is, we're looking at, back to old school biomechanics, we're looking at load to failure about 2,100 newtons. When we look at quad, we're looking at about 4,100, so almost double that of the native ACL. Patellar tendon, we're looking at about roughly, you know, about the same, 2,900. And then, I'm sorry, hamstring was 4,100, sorry, and the quad was about equal to that of native ACL. So hamstring, when it's quadruple, is about four times, two times the strength of a native ACL. Patellar tendon is roughly the same, as is quad tendon. So then we know, so I'm going to talk about the pros and cons of BTB and hamstring. So I think I feel like I have the easiest part of this talk, because this is something that's kind of gold standard we've used for a lot of years. There's a lot of data, a lot of research, a lot of outcomes on using these grafts. So we know that BTB autografts have a fairly high load of failure. We're looking at 2,900 newtons of failure. We know that there's very fast graft incorporation, so looking at bone-to-bone healing. And within animal models, we know that this bone-to-bone heals within three weeks of where the graft will fail at the bone-tendon interface, as opposed to at six weeks when the graft will actually fail at mid-substance. So we know that that graft has incorporated by that point. We know that a higher proportion of patients will return to the pre-injury level of activity based on literature, and there's a potentially lower risk of graft rupture. So now we look at hamstring autograft. Even though we have a quadruple graft, we look at there's relatively, even though it's a high load to failure, about double that of the native ACL. We know that there's lower donor site morbidity when compared to patellar tendon. We know that patients who have dumper's knee, patellar tendonitis, are more prone to patellofemoral pain. I mean, a hamstring graft might be the way to go. We know that there's a lower risk of anterior knee pain with an extensor strength deficit with a hamstring, and lower risk of osteoarthritis in the patellofemoral joint. And that's always the scary part, kind of down the road, 20 years. We know that post-traumatic osteoarthritis develops within 5 to 10 years post-reconstruction, but then we're also talking about 10, 20 years down the road, how much is that patellofemoral joint going to be an issue? And then, so healing for this is going to be a little bit different, right? We're looking at soft tissue to bone. So you want to kind of recreate those sharpie fibers and get that graft incorporated. So we know that in an animal prior to 12 weeks, the graft will fail at a tunnel bone interface, as opposed to after 12 weeks, that's when it starts failing at mid-substance. So we think that the graft will incorporate roughly at about three months post-op, compared to the patellar tendon, which is about six weeks post-op. So I don't think this is my updated talk. I had some cases in my other talk, so I apologize if this is not it. So let me go over some literature in terms of why we think patellar tendon and hamstring, and is there a difference between the two, right? So I found one of the older prospective studies looking at randomized controlled trials, looking at patients undergoing hamstring versus patellar tendon. This was published in Arthroscopy Journal in 2011. And looking at patients with kind of equal BTP, no hardware, press fit. There's basically no difference in range of motion. They're KT1000, as well as their pivot. Overall, patients only had issues with kind of kneeling pain or anterior knee pain, which we all know from the differences between patellar tendon and hamstring. But there was slightly weakness in hamstrings for patients who had hamstring grafts. So then now, I think as we start going into literature a little bit further, so this is published in AJSM in 2014. We're looking at kind of the Scandinavian registry, looking at 45,000, or actually almost 46,000 primary ACLs, where they looked at majority of patients actually in Sweden were getting 38,000 were getting hamstring grafts, so 84% smaller percentage were getting patellar tendon grafts. And the follow-up was about three years. So looking at revision rates for BTP versus the hamstring tendons, there was a risk of revision was much lower for the BTP, hazard ratio of about 0.63. And that would decrease risk with increasing age, which makes sense. Goes along with how much activity you're going to have, how much you're going to stress the graft, where's your risk of re-tear is going to be. So even though that hamstring is the preferred graft in Scandinavia, certainly BTP was statistically less likely for risk of revision. And it was similar across all ages and sexes. So sorry, this is, okay. So looking at this study, which is looking at a meta-analysis, more recently published in CORE in 2017 out of Mayo Group, looking at kind of a systematic review meta-analysis of kind of everything that's out there in the literature. So looking at randomized controlled trials, cohorts, registry data, and looking at primary outcome of graft failure. And so of 47,000 ACLs, 39,000 were BTP, 7,800 hamstring. Mean age of these patients was 28, with 63% undergoing BTP, 57% going hamstring. Mean ruptures, you see re-rupture rates are about 2.8 and 2.84, very similar. But if you can look, it's just a hint, slight increased risk of hamstring, just slightly increased risk. So then when we talk about cases in terms of optimizing, we're looking at, if you look at the 18-year-old, 17-year-old female lacrosse player, contact injury versus a non-contact injury. Are you going to do a hamstring on her or a patellar tendon graft? And I think with tried and true and literature to kind of back you up, you can probably say patellar tendon might give you just a slight improvement at risk of re-tear. But certainly, with this large review, looking at this many patients, it may not be that much of a difference. So finally, looking at the MOON cohort, which is our multicenter consortium study of seven sites, 17 surgeons, data collection started in 2002. Most recently, they published this in, I believe it was this year, looking at AJSM, was that they wanted to see the actual incidence of ACL revisions or contralateral ACL tears in that high school and college athlete. So that younger patient, that younger patient population that is going to stress that knee and potentially cause it to fail. So the hypothesis was that there was no difference between patellar tendon and hamstring grafts at six years for this prospective cohort data. So they identified 770 patients, six-year follow-up, about 48% were female, mean age was about 18. Patellar tendons were about 64% had patellar tendons, 36% had hamstring tendons. And the incident revision was about 9% on the ipsilateral side, 11% on the contralateral normal side. And overall risk of tear within that six years was about 20%. So we know that the highest predictor of revisions were, one, high-grade peroplaxity, two, graft choice. So graft choice is important. And three, age. So there's an odds for an ACL revision that's two times higher for hamstring as compared to patellar tendon. So this data certainly shows that patellar tendon probably is still considered the gold standard and I think it's up to these guys here to talk about the quad and how that might change your mind. So in conclusion, looking at long-term, there's long-term good to excellent outcomes with patellar tendon and hamstrings. We have a ton of literature to kind of support this. We know that both these grafts are rarely high load failure to strength with low donor site morbidity. That's it. Thank you. Good job.

ACL reconstruction

graft choices

bone-patellar tendon-bone

hamstring

quadriceps