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 shoulder, elbow 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 really give you options in regards to graft preference. And the big part of
the ACL reconstruction is basically taking a torn anterior cruciate ligament and
giving you a new anterior cruciate ligament and there are different ways of
doing that and there are different grafts that you can choose. And a lot of doctors
have their own preferences but I'll just say how we do things here. A lot of what
determines what type of graft we use here depends on the age of the patient,
activity status and then basically just patient's preference as well depending on
whether or not they're okay with receiving a little bit larger incision or a smaller
incision or whether or not they want a stronger graft overall. So basically the
way we break it down if you're a young, active individual say less than maybe 30
years of age, in their late 20's or so, and you have an ACL tear and you want to
go back to playing high contact cutting, twisting, pivoting types of sports and
activities. The strongest graft that we usually offer with the best outcomes per
long term studies is the patellar tendon autograft. Autograft means it's coming
from your own knee, okay. It's auto for yours and graft is obviously for the
graft. But it is coming from the patella 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 patella 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 usually close the
defect okay. And with each plug, it 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. And 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. And 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. And so the hamstring grafts are the central third of
the tendinous portion of the two hamstrings here which is the
semitendinosus and the gracilis okay. And basically it's a smaller incision too
than the patella tendon and it's usually on the distal aspect slightly medial and
we make a small incision here and we go and we 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. The big difference between the two is patella
tendon 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's going to be a little bit
different for the hamstring. 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. So typically the hamstring incision is
usually maybe a couple of, maybe one to 2 inches, 1.5 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, you don't want a scar or a large scar on your
kneecap then the hamstring may be a more valuable option if you're a younger player
that wants to get back to those cutting, twisting, pivoting types of sports because
once again the autograft shows better incorporation overall especially in that
younger, active population than say an allograft. So we've talked about patella
tendon, we've talked about hamstrings and now the third type of graft that you're
going to read about and hear about is something called an allograft. And that
means it 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 patella 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. And
so the Achilles works really well as well fixation-wise but it is an allograft. So
that being said that's not your tissue so that tissue actually is from a donor,
it gets sent off, it gets sterilized and prepared and then we basically 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 that 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. Usually it's for 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 really necessarily taking any bone from your patella 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
time 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 in the end typically 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 do an
ACL. 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.