Hi, everyone. Thank you so much for joining us for this ICL. I'm sorry that I can't be there with you in person, but I'm excited to have the opportunity to talk to you about Quad Autographed for ACL Reconstruction and focusing really on why it's a reliable and reproducible graft. These are my disclosures, none of which are directly relevant to this talk. I'm going to start with a case presentation and then touch a little bit on graft choice, but of course, focus on Quad Autographed for ACL Reconstruction. I'm going to give a little bit of the historical perspective of this graft and then touch on some of the studies related to biomechanics and clinical outcomes. This was a 29-year-old female who presented after injuring her left knee while playing co-ed rec soccer. She landed awkwardly and felt a pop in her knee. She had immediate pain and swelling and was unable to continue playing. On exam in clinic, she had moderate swelling about her knee. She had limited knee range of motion secondary to pain and swelling. She had some tenderness over the medial joint line and had a clearly positive Lachman. These were her x-rays in clinic, which were normal. Our initial plan was to order an MRI given the high risk of ACL tear. I started her in physical therapy to work on range of motion and gait training. Then we did start discussing what would be involved with ACL reconstruction, especially with regards to graft choice and overall timing for surgery. These were some of her cuts from her MRI. She had normal medial and lateral meniscus. That central sagittal image shows her ACL tear. On the far right, you can see the characteristic bone bruise pattern. A couple of her coronal cuts, again, demonstrating the bone bruising. In terms of graft choice, there are a lot of factors that influence our graft selection. Certainly, surgeon experience, preference, and comfort level is important. We take into account patient age and activity level. Additionally, their sport or occupation and desire to return to work or play are also very important. We want to keep in mind their comorbidities and BMI. Also, it's very important to consider whether the patients have high-grade pre-op knee laxity, if they have any history of previous surgery. Patient preference and expectations are critical. Also, we want to keep in mind any post-op rehab concerns. This table highlights the biomechanics of the native ACL. Then we can see the biomechanics of the many different grafts that we use. It's a little bit of a busy table, but the most important thing to take away is that all of these grafts are stronger than the native ACL. You can see quad autograft about halfway down that table. There are a lot of advantages to using quad autograft for ACL reconstruction, including that it can be harvested with or without a bone block. It's an incredibly strong, robust, and reliable graft. It can be harvested with a large diameter and can be used in primary and revision settings. Additionally, it causes minimal donor site morbidity, with regards to anterior knee pain and anterior numbness. There are some disadvantages, which include increased risk of proximal patella fracture if you harvest the bone block. There can be a lack of bone-to-bone healing if you use an all soft tissue graft. There's a risk of rectus femoris retraction or injury if you harvest up into the muscle belly. We can see a loss of extension and quad weakness similar to what we see with BTB. A little bit of the historical perspective. This graft actually was first described in 1979 by Marshall and colleagues, but it was a substitution graft, which involved extensive dissection and harvest of a 13-centimeter segment of the extensor mechanism, which included the quad tendon, prepatellar retinaculum, and patellar tendon. In 1984, Blouth reported the technique for harvesting the quad tendon with a patella bone block. In the 90s, Fulkerson and colleagues reported favorable results using the central third of the quad tendon with a bone block. Then in 1998, Fulkerson described the first technique for the use of all soft tissue quad autograft. In 1984, Stanisch found that there was a 20 percent incidence of post-op pivot chip test with a quad tendon substitution graft. In 1984, Noyes and colleagues using the quad tendon substitution graft again, found that it was significantly weaker than the native ACL. But very important to keep in mind that the substitution graft is significantly different from the quad tendon bone construct used in subsequent studies. At this point, the graft was actually largely abandoned because of poor clinical results. In the early 2000s though, there were some studies that describe the use of the central quad tendon free graft, i.e. no bone block. This eliminated the risk of patella fracture. There was reduced operative time, easier post-op rehab, and less risk of anterior knee pain. A study a little bit later in the 2000s by DeAngelis and Fulkerson found good to excellent outcomes using the free quad tendon graft. There was decreased donor site morbidity as well. At this point, they noted that the central quad tendon free graft seemed to be the least morbid of all currently used autografts for ACL reconstruction. A bit about the anatomy. The quad tendon is classically described as trilaminar with the superficial layer being the rectus femoris, middle being the vastus medialis and vastus lateralis, the deep layer being the vastus intermedius. Then there's a thin fatty layer that separates the rectus femoris and vastus intermedius. Based on MRI evidence, the quad can have two, three, or four layers, but again, most commonly it has three layers. With regards to length, it's usually about 7-8.5 centimeters from the myotendinous junction to the superior pole of the patella. The width ranges from about 2.5-3 centimeters, and the thickness is greatest at its distal insertion on the patella, but it's relatively constant throughout the distal six centimeters of the tendon. This study from 2013 again found that the thickness of the distal six centimeters was about 7-8 millimeters. The intra-articular volume of the quad tendon was 87.5 percent greater than that of a similar width patellar tendon graft taken from the same subject, and the residual quad tendon was greater than that left after patellar tendon graft harvest. With regards to vascular anatomy, there are contributions from three arcades, the medial, lateral, and peripatellar. The medial arcade is an anastomosis of the femoral artery descending geniculate artery, superior medial genicular artery division of the popliteal artery, and it's located between the muscular portion of the vastus medialis and the medial portion of the rectus femoris and vastus intermedius. In terms of the lateral arcade, this is from the long descending branch of the lateral femoral circumflex artery and that anastomosis with the superior lateral genicular artery. It courses between the rectus femoris and vastus lateralis. The medial and lateral arcades then anastomose within and below the rectus femoris musculature. A centrally based graft harvest within the quad tendon spares the lateral perforating vessels, avoids violation of the quad muscle, and mitigates the likelihood of post-op hematoma. Very, very important to harvest in the central portion of the quad tendon. For biomechanics, there are studies that demonstrate that the quad tendon is superior to BTV with regards to load to failure, strain at failure, and Young's modulus of elasticity. It has a significantly larger cross-sectional area and significantly greater ultimate load to failure. Important to note though, most of this data is based on quad tendon patellar bone block. This 2006 study found that the post-harvest extension strength of the quad tendon was higher than that of the intact patellar tendon, and that harvesting the central quad tendon actually leaves a stronger extensor mechanism than after harvesting the patellar tendon. For clinical results, there are a lot of studies looking at this. This 2017 study found comparable survival rates and joint stability when comparing quad tendon versus BTV, and there were fewer adverse donor site symptoms with the quad tendon autograft. This great 2019 study compared quad tendon versus BTV and hamstring. When looking specifically at quad tendon versus BTV, there was no significant difference with regard to several parameters. However, patients with quad autograft were noted to have less donor site pain. When comparing quads and hamstring autograft, again, very similar with several parameters, but patients with quad autograft had improved mean Leisholm scores. The authors concluded that quad autograft had comparable clinical and functional outcomes and graft survival rate compared with BTV and hamstring autograft, and that quad autograft showed significantly less harvest site pain compared with BTV and better functional outcome scores compared with hamstring autograft. Another very recent study found that the proportion of knees classified as higher than grade 1 on anterior drawer lockman and pivot shift decreased significantly post-op, and the overall complication rate was about 23 percent. A third of those patients underwent revision surgery as a result of graft rupture and residual instability. They concluded that ACL reconstruction using quad tendon with patellar bone block provided satisfactory long-term clinical results and acceptable rates of complication and donor site morbidity. Certainly, there's a question about whether we should use bone versus all soft tissue quad autograft. This recent study found that more bone quad tendon patients demonstrated rotatory laxity on pivot shift compared with soft tissue quad tendon, and there was no difference in re-rupture rate between graft choices. But still clearly, there's a paucity of literature comparing bone quad tendon and soft tissue quad tendon, so this is an area where some more work needs to be done. With regards to complications, there's a risk of bleeding and hematoma formation, especially if the quad muscle is violated and most specifically on the lateral aspect. Additionally, there's a risk of retraction of the rectus femoris muscle if the harvest spans the myotendinous junction, but there don't seem to be any functional consequences. Then there's a risk of patellar fracture, which is very rare. It's really comparable to the rate of patellar fracture with BTB. The bone block should not exceed 30 percent of the patella thickness and it should not be harvested from the lateral aspect of the patella. Now back to our case. The patient returned about two weeks later. She was able to ambulate normally. She was not complaining of any gross instability. Her range of motion had improved, and at this point, she elected to proceed with ACL reconstruction using quad autograft. These are a few pictures from her case. This is harvesting the graft. We released that using this cigar cutter, which works really well to harvest. This is preparing the graft on the back table, and this is really important, a really critical step of the whole process, because securing the tape to the graft, that's really what we're relying on. When you're first learning how to do this, it's important to take time to do this correctly. Then there's a few pictures from intraoperatively, so normal medial and lateral meniscus, and then that central picture shows the stump of her ACL. These are a few pictures from the tunnel. So you can see the femoral tunnel, which I drill retrograde. On that top right, you can see the button being advanced into the femoral tunnel, and then on the bottom right is the graft in place. I then put the knee in full extension, and I'll secure that in the tibial tunnel using a biocomposite interference screw, and back that up with an anchor. These are the patient's postoperative x-rays. I start her in physical therapy a week after surgery, and she is actually doing quite well now, about seven months out from her surgery. So in summary, quad autograft is a fantastic option for ACL reconstruction. It can be used for primary or revision cases. There's less harvest site pain compared with BTB, and better functional outcome scores compared with hamstring autograft. So really, we encourage you to use it now, use it often. It's a great graft. Definitely add this to your toolbox, and I know you're gonna be hearing some more about some tips and tricks with regard to technique from Dr. X. So thank you so much for your attention. I would be very happy to answer any questions. Please reach out to me via email or social media. Thanks again for being here, and huge thanks to my colleagues, Dr. Clay, Nali, Cassandra Lee, and Dr. John X, for participating in this ICL. Enjoy the rest of the meeting.

Quad Autograft

ACL Reconstruction

graft choice

biomechanics

clinical outcomes