All righty, good morning. So this morning we'll talk about how to optimize ACL reconstructions and how BTB and hamstring are the gold standard. So I have some disclosures. So let's start with cases. So just typical case scenarios you're going to see. So the first one I have is a 21-year-old female collegiate soccer player, side tackled by a defender causing a valgus moment in her right kicking knee. No other prior injuries except a prior ankle sprain, but physical exam-wise, slight hyperextension, Lockman 2B, Pivot 2B, non-explosive, and no joint line tenderness, negative memories and negative valgus stress. So you can see kind of the picture I'm trying to paint here, probably an isolated ACL tear. Case two, we have an 18-year-old right-hand dominant middle blocker performing a back slide, lands awkwardly on his left knee, filling the knee buckle, but in prior history had a right ACL tear at the age of 16, and then patellar tendonitis in that same knee. So range of motion-wise, exam, range of motion 0 to 130. So normal full range of motion, Lockman 2B, Pivot Shift 1+. So just keep those two cases in mind as we go through talking about why BTB and hamstring auto are the gold standards for ACL reconstruction. So let's just talk about this up front. Allograft probably for these patients is not a great option, right? We know that from the MOON cohort studies, so the prospective cohort looking at primary ACL reconstructions, and we know that overall, allograft does have a higher failure rate, and that's dependent upon age as well as activity level. So but overall, the it's lateral ACL retear rates 5.2 times greater with an allograft compared to BTB autograft, and odds of retear between BTB and hamstring, there's really no difference. So again, this goes back to probably surgeon choice in terms of graft options. So when we think about ACL reconstructions, we want to talk about what you want requirements out of an ACL graft, right? Ideally, you want something that's about seven centimeters in length. You want something that has a good mid-substance cross-sectional area that's similar to that of the native ACL. So graft options that we have right now are BTB, hamstring, or quad tendon. So BTB, I think, is considered the gold standard. We have a 10 millimeter wide tendon strip. We have two bone blocks. The collagen itself in between is flat, and there's less collagen fibers than, say, like a quad tendon. Hamstring can be variable in terms of how many strands you want to make in terms of how wide you want your graft to be. Quad jubilant is the most common option, and this is, again, related to patient anthropomorphics. The sports is patient-dependent factors, right? So this may not be as predictable in terms of grabbing a graft. There is more collagen and fiber less than a patellar tendon, but overall, again, those are mostly the likely gold standards. Quad tendon, I'll have my fellow speakers talking about that. You can do a quad tendon with or without bone block. There's probably about 20% more collagen fibers than, say, BTB in a cross-section. So these are graft characteristics. So it always goes back to the biomechanics. It always goes back to the basic science. So these are patellar tendon, hamstring, and quad tendon. So you can see the comparative to the native ACL, load to failure is relatively similar. So between patellar tendon, quad, as well as to the native ACL, you can see quadruple hamstring is much higher than that for load to failure. And then if you look at the cross-sectional area, in terms of the cross-sectional area, the highest is probably going to be the quad tendon, which may be actually wider and bigger than the native ACL. When you think about how biologically this incorporates and how we get our patients back to play, with BTB, we have a bone-to-bone healing. So it's like a nice fracture healing. We know that's predictable and consistent within six weeks, eight to 12 weeks for the graft to fully incorporate. And then when we look at quad tendon, we look at soft tissue to graft healing can be a little bit longer in the eight to 12-week range. So we know BTB autograft has high load to failure rate, fast incorporation within animal models. Six weeks, the graft fails at mid-substance. So for all intents and purposes, in an animal model, the BTB incorporates within six weeks. We do know that from vast amount of literature that there's a higher proportion of patient return to pre-injury level of activity and there's pretty low risk of graft-free rupture. But it's not without problems, right? There's risk of patellar femoral pain, loss of range of motion, patellar fracture, even patellar tendonitis in terms of the rehab protocols. Hamstring also has a very high load to failure rate, higher than that of the native ACL. The donor site is a little bit less compared to patellar tendon. What patients have an issue with are potentially risk of flexor strength, the variability in the hamstring size, and fixation hardware limitations, right? You're looking at suspensory fixation that might be an issue. And there may be delayed incorporation compared to that of a BTB. We know that it takes probably about after 12 weeks in animal models, the graft fails at mid-substance. So when that bone and tendon tissue interface does mature a little bit more. So when you talk about how to approach our two patients, right? So we have a soccer player, cutting, twisting, pivoting sport. We have a volleyball player, all high-intensity sports. So factors to consider is you want to look at autograft versus allograft. And again, I would make an argument in this age group, in this activity level, that allograft is not an option. You want to look at sex differences. You want to look at sporting activity, right? What is their expectation? What is their sport? And any contraindications. If there's any other comorbidities, if, say, patellar tendonitis is an issue, you probably don't want to take a patellar tendon. So let's talk about outcomes. So what is the difference? And the reality is there is a ton of literature out there, and there really is no difference. So I'm going to go kind of back like 10, 15 years, up until kind of more modern kind of outcomes. But looking at prospective studies, there's no difference between a hamstring and patellar tendon. This is an interesting study where there's actually no hardware. This is a press fit looking at patellar tendon and hamstring tendon. And there's basically no differences. The only difference was that there's no anterior knee pain with hamstring tendon, and there's a weaker hamstring tendon when you take your hamstring. So in terms of the Scandinavian registries, so looking at 45,000 primary ACLs, majority are going to be hamstring, right, 38,000 hamstring and 6,700 patellar tendon follow-up in 3 years. The risk of revision for BTB is much lower for a hazard ratio of 0.63. And there's a decreased risk with increasing age at the time of surgery, right? So this is an issue of when you look at revisions and looking at likelihood of failure, you're looking at mostly age issues, which goes back to how active are they and how well are they expecting from their sport. So BTB statistically had less risk for revision, and that was slightly more obvious when it comes to cutting, twisting, pivoting sports. So this meta-analysis, again, 10 years ago, looking at multiple trials showing that hamstring would tend more towards loss of flexion range of motion, and patellar tendon had better Lockman pivot instrumented laxity. But they did have a little bit loss of extension. So depending, you have to rob Peter to pay Paul, and you want to choose kind of what issues you might have in terms of your deficit. So again, study after study showing no difference, basically, between patellar tendon and hamstring tendon. So looking at this MOON cohort, again, looking at multiple sites, and that there's a hypothesis that there's no difference between patellar tendon and hamstring tendon at six years. And so these are some of the cohorts, 7,700 patients, six-year follow-up, about half are female. A little bit more patellar tendon compared to hamstring. Incidence of revision at six years was 9.2 on the ipsilateral, 11.2 on the contralateral, and 19.7% on either knee. So the highest predictor for revision is the high-grade preoperative laxity. And again, we'll probably address this with some of the other talks we're going to have. Graph choice and age. So the odds of ACL revision was two times higher for that for hamstring compared to patellar tendon. But again, all of our literature looks at hamstring versus patellar tendon, and I think that's because it's the gold standard. So long-term outcomes, this is kind of an interesting study looking at truly long-term outcomes for patients with mean follow-up of 20 years. So again, 2,000 patients, looking at some patients who had patient-reported outcome for follow-up versus patients who actually had in-person evaluation. Obviously, you can think at 20 years, you're going to have fewer patients actually showing up for a full physical exam. But overall, you can see the graft tear rate is about 11.8%, contralateral side about 12%, knee arthroplasty is about 5%. So arthritis is definitely associated with more of a meniscus issue rather than the potential of the ACL itself. So when you're talking to your patients, you know, graft choices are going to be autograft, and I would make an argument for patellar tendon versus hamstring and highly active cutting, twisting, pivoting sports in our adolescent athletes. So overall, I would say long-term, we do have good long-term good to excellent outcomes for patellar tendon and hamstring tendon. These have been the most studied for the longest amount of time with a ton of literature on it. Overall, there's an 81% return to sport, 65% return to pre-injury level, kind of all-comers. Both grafts are a very high load of failure strength and low donor site morbidity. So thanks. Thanks.

ACL reconstructions

BTB graft

hamstring autograft

graft options

biomechanics