Hi, everyone. My name is Nate Endres from the University of Vermont. Welcome to the 7th Annual Anna Fellows in Chief Residence Course. I hope you have a great experience at this course. I was tasked with the topic of ACL graph selection in 2024, and specifically the question as to whether or not there is a gold standard for ACL graphs. To start with, let's go over some definitions. So what is the gold standard? Well, technically, for those of you who are history or economics majors, the gold standard is a monetary system whereby a country's currency has value directly linked to gold, but in more general terms, the gold standard refers to a benchmark or an example by which others are measured. So we need to look at what our measurement outcomes are, and there are a number of different outcomes that one can look at with regards to ACL reconstruction. We can look at outcomes from the surgeon's perspective versus the patient perspective. Some outcomes are objective versus some that are subjective, and these may include, this is not an exhaustive list, but these may include the presence or absence of a stable knee, the presence or elimination of a pivot shift phenomenon, Lachman's testing, potentially with the use of KT devices, return to function or sport, patient-reported outcomes, which are a very important consideration, and then surgical morbidity. So it's important to keep this in mind when discussing different graphs. What outcome are we referring to? So I think one way to look at this is the concept of the surgeon as a risk modulator, and I think that's relevant when you're looking at different graphed options. And we can go through the various options here and look at the pros and the cons, and this is not meant to be a complete review of all the different pros and the cons, but these are some things to think about when trying to figure out what graft might be best for a particular patient. So we'll start with kind of the original bone patella tendon bone autograft. Pros of BTB autograft include bone-to-bone healing within the tunnels, potentially lowest rates of re-rupture and highest rates of return to sport. That may be somewhat debatable, but there are a number of studies that bear that out, and potentially earlier return to sport, which may be important for some of our patients. Cons include graft tunnel mismatch, and I would encourage you to talk to your instructors during this course about ways to manage that. Anterior knee pain is obviously the main issue with patella tendon autograft, as are other extensor mechanism complications, including patella tendon rupture and patella fracture. And some studies suggest there may be an increased risk of post-traumatic osteoarthritis with BTB autograft. So hamstring autograft is obviously another option. Pros include favorable biomechanics in terms of load-to-failure, graft tunnel mismatch is much less likely compared to BTB autograft. It could be used in pediatric cases, which is not the case for a BTB, and there may be a lower risk of post-traumatic OA. Cons include tendon-to-bone healing, which is felt to be slower than bone-to-bone healing. The size of the graft is variable, and multiple studies show that the size of the graft is important with regard to failure rate. Hamstring weakness could be an issue for some patients, and there's concern, particularly in the female athlete, using hamstring graft and whether that may affect re-tear rates and re-injuries. Some studies show more laxity, as well as other measures of stability. And there may be a higher re-tear rate, depending on what study you're referring to. Quadriceps tendon autograft has become increasingly popular. Pros include less anterior knee pain compared to BTB autograft. It's a very versatile graft and can be used in pediatric and revision cases. It can be harvested with bone or purely as a soft tissue graft. Studies show that it really shouldn't matter. The biomechanics are very favorable, and the outcomes, clinically, are favorable in terms of re-tear rates and return to sport. Cons include, obviously, quadriceps weakness and the potential for patella fracture if you do harvest the graft with bone. Allograft is yet another option. Obviously, there's no donor site morbidity. And for some patients, that may mean an easier, earlier recovery. But particularly in the younger, active population, there clearly is a higher re-tear rate. And overall, it may take longer for the graft to heal and remodel. Additionally, there are other options, specifically iliotibial band autograft, which can be used as a primary graft, if you will. This is well-described in pediatric cases. And it can also be used as a secondary graft or an augment, which may decrease the rate of failure of your primary graft. And certainly, we'll talk about that in the course. So in conclusion, I think the key here is to understand the patient goals and expectations when deciding on a graft. Is there a gold standard? Well, I think if you look at re-tear rates and return to sport, which are obviously very important outcomes, I think a strong argument could be made for patellar tendon autograft. But I don't know that that's the best graft for everybody. So if you have a patient who has a super solid endpoint, no pivot shift, but they can't kneel down to play with their kids or their new puppy, then arguably, that's not a great outcome for that patient. So I don't think there's any universally ideal graft. And I think it's important if you're going to do a lot of ACL surgery, and I assume many of you will, it's important to be familiar with multiple grafts. Thanks.

ACL graph selection

University of Vermont

gold standard

graft options

patient goals