Hello, my name is Clay Milley with the University of Missouri, and I will be discussing ACL graft selection, quadriceps tendon graft. My disclosures are on the Academy website. There are many graft options to choose from when considering anterior cruciate ligament reconstruction, including patellar tendon, bone tendon bone, or BTB, hamstring tendons, allograft tendons, and the quadriceps tendon. There are many factors at play that influence graft selection, including patient demographics, patient activity level or demands, and surgeon preference. Patellar tendon, BTB, has historically been considered the gold standard and certainly has many positives for ACL reconstruction, including bone-to-bone healing and being a reliable graft. Some of the negatives associated with it, however, include anterior knee pain, a small tendon thickness or diameter, oftentimes only three to six millimeters as the patellar tendon is more of a ribbon as opposed to a thick type of graft, and also the patellar tendon with bone plugs typically requires screw fixation, which when they are biocomposite or bioabsorbable can cause cyst formation, or if they're biocomposite or metal screws can actually lead to difficult removal and revision settings. Hamstring tendons have also been a reliable and often utilized graft. The positives of hamstring tendons is no anterior knee pain, particularly when harvested from a posterior approach as seen in the picture to the right, and you're sometimes able to utilize multiple tendons, including both the gracilis and the semitendinosus to create a larger graft. Some of the negatives of hamstring tendons are that it can weaken the posterior chain and thus create a risk factor for quadriceps dominance, which then is known to be a risk factor for ACL retear, particularly in females who have quadriceps dominance at baseline. Hamstring tendon grafts are also often produced less predictable graft size and frequently will result in small grafts, particularly in smaller patients where they have smaller native tendons, and often to create a thick enough graft or a thick enough diameter, you need to do a multi-stranded graft, whether or not you use semitendinosus and quadruple or quintuple it over, or you utilize gracilis and add that and double it over as well. Allograft is another often utilized graft source. The positive of an allograft tendon is no harvest site morbidity and a very predictable graft size that the surgeon creates. The negatives are that there is oftentimes poor quality tissue associated with an allograft, which can lead to prolonged graft incorporation, and there's documented increased failure and retear rates with allograft versus autograft. In fact, much of the MARS data and some of the MOON study group data has shown that there's a much higher risk of retear and allograft in younger patients in particular, and it's not recommended to utilize allograft in patients less than 25 years old. And in my particular practice, I do not use allograft in anyone less than 40 years old or anyone very active. That brings us to the quadriceps tendon. Use of the quadriceps tendon for ACL reconstruction has been around for a number of years, as it was described by John Fulkerson and his colleagues back in 1995. They described taking a central strip of the quad tendon with a proximal bone plug from the patella. They described it as a very large and excellent, robust graft, but that it was a very demanding harvest and was not easily harvested through simple, small incisions during that time. There are many benefits to the quadriceps tendon graft. It gives you a very predictable graft size as the surgeon actually determines the width of the graft, and the thickness of the graft can actually typically be predicted on preoperative MRI imaging, as you see to the right. The graft itself is typically 20 to 50 percent greater thickness than BTB or hamstring tendon, and typically has 20 percent or more collagen per millimeter squared circumferentially within the graft, so it's a very thick and robust piece of collagen tissue. There are multiple fixation options, and you can take a bone plug from the proximal patella, or you can do an all soft tissue graft with fixation accordingly. There is minimal soft tissue disruption with some of the newer devices, with less donor site morbidity and less anterior knee pain than you typically would see with the BTB graft, and you have a balanced anterior and posterior chain, so there's very minimal to no post-op physical therapy limitations when doing an isolated ACL graft with a quadriceps tendon. What about the literature of quadriceps tendon versus the other grafts? This is a nice prospective randomized trial by Lund and Au looking at quad tendon versus BTB. It was 51 patients with 25 in the BTB group and 26 in the quad tendon with the bone plug group. They looked at a number of different outcome studies, and the results showed that there was anterior knee and graft site pain that was significantly less for the quadriceps tendon at 7% versus BTB, with over a third of the patients having that, but there were similar anterior laxity and subjective outcome scores, so their conclusions was that quadriceps tendon is a viable graft option for anterior cruciate ligament reconstruction, particularly relative to BTB. How about quad tendon versus hamstring? In this study, first here you see that there was 51 quads versus 45 hamstrings, and they used the exact same technique and fixation method. It had a little bit longer follow-up. The outcome scores were actually significantly better for the quadriceps tendon, and stability was actually slightly better on KT1000 testing for the quadriceps tendon as well, so their conclusions were that the quadriceps tendon was equal or better in functional outcomes to hamstring. In the second study by Reuner and Au, they had 875 patients at two-year follow-up. There was no differences in the patient-reported outcome measures, but the odds of revision surgery were both greater in younger patients, which has also been shown and documented elsewhere, but also much greater in the hamstring tendon versus the quad tendon, so their conclusion was that the hamstring tendon graft had a significantly higher risk of needing revision than the quadriceps tendon. These are some current systematic reviews pertaining to the quadriceps tendon. The first study by Sloan and colleagues was a systematic review of 14 studies in over 1,154 quadriceps tendon ACL reconstructions, and they showed stability. Patient-reported outcomes, range of motion, and complications were similar between quadriceps tendon and BTB in hamstrings, but there was less donor site morbidity in quadriceps tendon versus BTB. The second study was a systematic review of 27 studies in 2,856 patients, no differences in Lachman's or pivot shifts, so no differences in stability testing, no differences in patient-reported outcome measures, no differences in graft failure, and again, quadriceps had less donor site pain than BTB, so their conclusions were that there were similar functional and clinical outcomes to BTB, actually slightly better functional outcomes than hamstring tendon and less donor site pain than BTB. So as I mentioned previously, Fulkerson first described the quadriceps tendon harvest and noted that it was a very difficult harvest, and that was frequently why people did not utilize quad as a primary graft, as it sometimes was a difficult harvest or there was a lot of donor site morbidity associated with that. The quadriceps tendon is obviously a very thick tendon and a very robust piece of collagen that makes for a great graft, but the harvest was sometimes difficult, but with modern instrumentation, we now have more minimally invasive and less morbid harvesting techniques with smaller incisions, less soft tissue dissection and stripping, less donor site morbidity, and you can either harvest with or without a bone plug, depending on your preference. This is a nice infographic published by John Zeroyans out of Emory in Atlanta on the quadriceps tendon for ACL reconstruction that can be found in the arthroscopy journal, showing how the graft can be minimally invasively harvested, and then also simple graft preparation, in this particular case for an all soft tissue graft. I'll briefly show the steps of the harvest technique here. As you can see in the first picture, you can utilize a very minimally invasive incision of about two to four centimeters, and it can be either a vertical or horizontal incision. Tendon stripping is first completed with a double-edged scalpel to make it the width that you desire as the surgeon that you select as the exact diameter and width, which is typically anywhere from nine to eleven millimeters, and then you can use a circumferential tendon stripper that actually has length measurements on it so you know how long of the tendon you're cutting and stripping, and you can take either a partial or a full thickness graft as you see being completed in the picture at the bottom right. The skin closure from the harvest site can be done with either a small curved needle like a UR6 needle pictured here in the first picture, or can be done with a self-passing suture device and looking underneath using the self-passing suture device. It can be done through small incisions like this one that you see. It's only about three centimeters, but I recommend when you first start doing this technique, if you start doing it, is you utilize a little bit larger incision so you can understand the anatomy and get an appropriate graft, but as you get more facile and comfortable using this, the incision can get much smaller and smaller and less minimally invasive. The graft prep, as I stated before, can be done with either a bone plug on one end or an all soft tissue graft depending on surgeon preference. If doing an all soft tissue graft, you can utilize cortical suspensory fixation on both sides as you see pictured in the picture on the bottom left. Typically your graft lengths are anywhere from 60 to 70 millimeters in length, and your graft diameter can be anywhere from 8 to 11 millimeters in diameter, again depending on how the surgeon individually preps the graft. I typically like to utilize an all inside technique, which you see pictured in the picture on the bottom right hand corner, which works very well with a quadriceps tendon graft. Here you can see a final autograft quadriceps tendon ACL reconstruction pictured intra-articularly in the picture on the left within the notch, and the post-operative x-ray in the picture on the right demonstrating the cortical suspensory fixation on both the femur and the tibia for the all inside quadriceps ACL reconstruction. Here you can see some of the post-operative clinical images and radiographic images. In this particular patient, you can see they had bilateral quadriceps tendon autograft ACL reconstructions performed. You can see the incisions are very cosmetic, and the patient has excellent range of motion and excellent cosmesis after having this surgery performed. In the middle MRI images, it's a six-month post-operative MRI where you can see excellent graft incorporation, and the MRI image on the far right is a one-year post-operative MRI with a quadriceps ACL, where it looks essentially almost like a native ACL, but you can see a little bit of the signal from the cortical button on the tibia, and the graft is in excellent congruity and excellent position at one year post-operatively. So, in conclusion, the quadriceps tendon versus BTB, the quad has less donor site morbidity, less anterior knee pain. You get a larger thickness graft, but it has similar patient reported outcome measures, similar knee stability scores, and similar re-tear and revision rates, depending on the study quoted. Quadriceps tendon versus hamstring, quadriceps tendon is a more predictable graft size and, again, has larger thickness, particularly in smaller patients, especially smaller females. There are no changes to the posterior chain and, thus, no changes to the anterior and posterior biomechanics with quad tendon. The patient reported outcome measures are, again, very similar, and, again, they're similar or even slightly decreased re-tear and revision weights for quad tendon versus hamstring, again, depending on the study. With modern instrumentation, the harvest technique is straightforward and can be done in a minimally invasive fashion, and that results in a very robust and biomechanically strong graft that is excellent for autograft intracruciate ligament reconstruction. So with all of that information and data, you can see why you should LOD the quad. Thank you for your time. My contact info is listed on the slide. Please feel free to email me or message me on social media at either the email address listed here or the handle listed here with any questions. Thank you for your time. My contact info is listed on the slide. Please feel free to email me or message me on social media at either the email me or message me on social media at either the email address listed here or the handle listed here with any questions.

quadriceps tendon

graft options

ACL reconstruction

patient demographics

comparative outcomes