Oh boy, why did we have to start with such a heavy-hitting question today? It is a very important topic, so here are some orienting facts about different graft types.
ACL Graft Sources: Autograft or Allograft
When you tear the ACL or “that cross-shaped binding thing near the front,” it is just like tearing a rope that was holding the two bones together. Now we need something to replace it with. Your choices start with two overall categories of graft tissue types:
- It comes from you – an autograft (auto- means “self” in Latin)
- It comes from someone else – an allograft (allo– means “other/different” in Latin). That someone is usually a dead person, a cadaver – I am sorry, but that’s the truth. Don’t worry, these grafts are well-prepared and hygienic.
Graft Tendon Options
Once you’ve figured out the graft source selection part, you will have to choose from the following three locations:
- Patellar tendon – the ligament that runs between the knee cap and shin bone (bottom of picture). This graft type is also known as BPTB, or “bone-patellar tendon-bone.”
- Hamstring tendons – the muscles that bend the knee in the back of the leg (left side of picture below)
- Quadriceps tendon – the large tendon that runs between the knee cap and thigh bone (top of the picture below)
AAAAAAAAHHH! We are talking about dead people and learning Latin. Is your head spinning yet?
Hang in there, almost done.
Pros and Cons of different ACL grafts
Here is a table to help you decide, based on research and outcomes of thousands of other people who have had ACL surgery.
| Graft Type | Self /Autograft | Cadaver /Allograft | Quad Auto | BPTB Auto | Hamstring Auto |
|---|---|---|---|---|---|
| Pros | Low risk of infection
Better healing |
Don’t have to give up your own tissue from elsewhere
Lesser pain |
Very strong and large tendon | Very frequently used
Lots of research Strong tendon Good ACL healing within the bone |
Very frequently used
Lots of research on it Very little pain during recovery |
| Cons | Pain at the donor site | A small risk of disease transmission (1 in 1.6 million)
Chance of rejection Possible graft laxity down the road |
“Newer” technique – used since the late 1990s
Fewer research studies done |
Pain in the front of the knee during rehab
Pain with kneeling Largest scar from the harvest site |
Possible hamstring weakness |
Usually when you learn a lot you end up having more questions. So don’t worry if all of this is as clear as mud. The bottom line is you need a good surgeon who has done a lot of these ACL procedures and is well-versed in whatever technique he chooses. I once observed a surgeon as he completed the whole ACL surgery in a whopping 20 minutes! I think he had done just a few thousand of these.
From the PT standpoint, I have seen people with hamstring autografts do better than BPTB autografts due to less knee pain during the rehab. I have not seen quad tendon grafts and allografts used as much in the clinic so my own jury is still out on those two graft types.
Further Reading
In case you haven’t had enough Latin and anatomy, here are a few more links with more detailed information. I ranked them in the order of relevance and helpfulness (links will open in a new window).
- Comparison of all graft types, considering multiple factors: pain, function, graft stability, donor sites, risk of infection, rate of re-tear, laxity: Anterior Cruciate Ligament Graft Choices. 2012.
- Very simple reference with good visuals for more anatomy pictures: “Which ACL Graft Is Right for You?”
- Comparison of quad to patellar tendon autografts: Is quadriceps tendon a better graft choice than patellar tendon? a prospective randomized study. 2014.
- Comparison of quad to hamstring tendon autografts: Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon autograft: clinical outcome in 4-7 years. 2006.
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I see clients in Southern Illinois and Missouri.
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