Call 281-633-8600 for our Sugar Land Clinic and 713-234-3152 for our Houston Clinic. If you think you might have an anterior cruciate ligament or ACL tear, you probably have lots of questions about graft options for ACL reconstruction. In other words, you’re wondering how your orthopedic surgeon will be able to replace your torn ACL with a new ACL.
Dr. J. Michael Bennett guides you through the procedure in this video describing the typical graft options for ACL repair. He’s a Board Certified Orthopedic Surgeon and a Fellowship Trained Sports Medicine Specialist with many years of experience in treating ACL injuries and repairing ACLs.
Hi there. My name is Dr. J. Michael Bennett. I am with the Fondren Orthopedic Group. I’m a Fellowship Trained Sports Medicine Physician with my Certificate of Added Qualification in Sports Medicine. We primarily treat shoulders, elbows and knees.
Today we’re going to talk a little bit about one of the big questions we get often and asked in our clinic and a lot of you out there may have some questions as well regarding it.
First off when you’re told that you have an ACL tear that’s pretty big news and a lot of you don’t know really what to do or even what to think at that point. But the first thing that your doctor should go over with you is that you have options in regards to graft preference. The big part of the ACL reconstruction is removing a torn anterior cruciate ligament and giving you a new anterior cruciate ligament. There are different ways of doing that and there are different grafts that you can choose.
Most doctors have their own preferences but I’ll just talk about how we do things here at my practice. What determines what type of graft we use to repair an ACL tear depends on the age of the patient, the patient’s activity status, and the patient’s preference. The patient’s preference for repairing the ACL tear might depend on having a little bit larger incision or a smaller incision or whether or not the patient wants a stronger graft overall.
So basically the way we break it down in repairing your ACL tear is to start with your activity level and age. Are you a young, active individual, say less than maybe 30 years of age, in their late 20’s or so? Do you want to go back to playing high contact sports with cutting, twisting, pivoting movements?
The strongest graft that we usually offer to repair an ACL tear with the best outcomes per long term studies is the patellar tendon autograft. Autograft means it’s coming from your own knee. It’s auto for yours and graft is obviously for the graft, but the graft is coming from the patellar tendon.
So if you look at the knee anatomy and you look at your knee here this is the quadriceps in the knee. This is the patella here and here’s the patellar tendon and it starts right here in the tibial tubercle. And usually what we do is we harvest the central third of that tendon so that way you have a bone plug on either side.
So you basically take a little saw and you take a little plug of patella and you take the central third of the tendon and you take a plug of the tibia here. And then after that we close the defect. Each plug gives you very good bone integration.
So when you’re doing an ACL reconstruction, you’re drilling two holes, one in the femur then one in the tibia and you’re passing a graft through those holes and you’re fixating them on either side.
Typically the graft will look something like this. This is just a plastic model but it shows you the patella bone and the tibial bone, and then the central third of the graft and then you fixate it on either side with whatever doctor’s preference is. Usually we use a screw of some sort and it could be either metal or it can be absorbable and you fixate it on either side. This is what the graft looks like with the little drill holes and the pull string.
Now another graft that’s a very popular graft is the hamstring graft. Now one of the big differences between the patella tendon and the hamstring is that the patella tendon has bone on either side and the hamstring grafts are just soft tissue.
The hamstring grafts are the central third of the tendinous portion of the two hamstrings here which is the semitendinosus and the gracilis. It’s a smaller incision too than the patella tendon, and it’s usually on the distal aspect slightly medial. We make a small incision here and we go and just harvest the hamstring tendon.
Now when you think of hamstring a lot of people think it’s up in the muscle belly hamstring. That’s not true. It’s just the tendinous portion of those two hamstrings. And once you harvest those hamstrings this will heal and you will return to activities as tolerated once that is healed up. So you can actually sacrifice these two hamstrings in order to get a good graft. And another benefit of that is that it is once again autograft so it’s your own tissue.
The big difference between the two is patellar tendon graft gives you bone to bone ingrowth because you’ve got a plug here of bone growing to the femur, which is bone to bone, whereas the hamstring is going to be tendon to bone ingrowth. So the fixation is going to be a little bit different for the hamstring graft.
What we usually use is something called an endobutton or a button that we actually put around the hamstring. It’s like a little anchor here. We pass the graft through, the graft gets embedded into this little socket here and then there’s a little button on the outside that kind of locks it into place in the outer cortex. And then over on this side we have a screw actually that fixates it here.
Typically the hamstring incision is usually maybe one to 2 inches. The patellar tendon incision usually goes from the inferior pole patella down to the tibial tubercle so it’s a little bit larger incision for the patella tendon.
So if cosmetics are an issue for you, and you don’t want a scar or a large scar on your kneecap, then the hamstring graft may be a better option for repairing your ACL tear.
If you’re a younger player who wants to get back to those cutting, twisting, pivoting types of sports, either the patellar tendon graft or the hamstring graft might be appropriate because once again the autograft shows better incorporation overall than an allograft.
So we’ve talked about patella tendon graft, we’ve talked about hamstring graft and now the third type of graft that you’re going to read about and hear about is something called an allograft. That means that the graft comes from a third party. It comes from a donor.
So you can actually get any of these tendons from a donor. You can get a patellar tendon allograft, you can get a hamstring allograft or you can even get an Achilles allograft, which some doctors will use as well because it’s a very robust tendon with a single bone plug on one side. So the Achilles works really well as well fixation-wise but it is an allograft.
Since the allograft is not your tissue, it gets sterilized and prepared for use and then we use that as a graft substitute. The problem with some of these allografts is that the studies have shown that there is a slightly higher failure rate in very young patients who participate in a lot of these cutting, twisting, pivoting sports and activities.
So usually I start mentioning allograft as an option to some of my older patients who are usually 30 years and up and maybe want to go just do some recreational ball or just want to play with their kids. They’re not necessarily out there every weekend competing either in pro football, collegiate football, any kind of pro, collegiate sports or activities. The allograft option is usually for repairing the ACL tears of the weekend warriors.
It’s a good option but it is an option nonetheless and the benefit with the allograft is that you’re not harvesting anything from yourself. That way you’re not taking any bone from your patellar tendon or taking your hamstring. You get to keep all your own tissue and you’re using tissue from a third party.
But that being said once again it may take a little bit longer for your cells to populate that allograft because that allograft is basically a blank slate. It’s like a scaffold of collagen that we put into the knee and then your cells will over time populate that scaffold and it becomes a part of you over time.
So the recovery phase in the postoperative course usually is about the same in the end when you’re looking at returning to high contact cutting, twisting, pivoting activities. And it’s anywhere from six months sometimes up to a year depending on your type of therapy and your recovery. And everybody’s a little bit different regarding that.
But that’s really just some basic information regarding graft options and it’s something that you should talk about with your doctors when you’re deciding to repair an ACL tear. You’ve got to know the different types of grafts that are out there and which one is best suited for you.
So if you have any other questions, please go to our website or please call us at the office at 281-633-8600. Thank you.
Click this link to see more videos Dr. Bennett has recorded about knee injuries. If you’ve injured your knee and you’d like to have it evaluated by Dr. Bennett, please call our Sugar Land office at 281-633-8600 and our Houston office at 713-234-3152 for an appointment. You can also click this link to see a video by Dr. Bennett describing a typical knee examination so you’ll know what to expect. We also have a more recent video describing ACL graft options.