Physical Therapy Continuing Education - ACL Reconstruction Surgery - Use of the Hamstring Graft

Physical Therapists spend much time in Physical Therapy continuing education courses learning how to rehab patients after ACL surgeries, but rarely due we get taught about the surgery itself. We recently interviewed an orthopedic surgeon to ask him some questions about the use of the hamstring graft in ACL reconstruction surgery. Here are some of his answers.

PhysicalTherapyContinuingEducation: So to summarize on the use of hamstring graft in ACL surgery, the biggest advantage of the hamstring graft would you say, I think you alluded to earlier, that it is an easier rehab period with less pain. Are they the two major points, or are there other?

ACL Surgeon: I think the advantages are that it's a very strong graft that has actually, bio-mechanically, when you double up the two strands of the hamstring and basically have a four strand graft it's actually a stronger graft initially than the patella tendon. It actually now has stronger fixation. It is not quite as painful as taking the patella tendon and the rehab I think is initially a bit easier. I think with time that evens out. And the results now clinically are as good as patella tendon.

So, I think there are a lot of advantages. It is a smaller incision as well, so that may come into effect, particularly with those that are conscious of cosmesis. But, as we know, that's not the most important factor, but to some that may be.

PhysicalTherapyContinuingEducation: Fantastic. Let's talk a little bit more about the graft and the fixation. When we say we use the hamstring, what specifically do you use? And then on the fixation, you mentioned that there was some advancement in fixation. Could you just expand on that a little bit too?

ACL Surgeon: The grafts that we typically use for hamstring are the gracillis and the semitendinosus, and these are two long tendons that are attached to some of the hamstring muscles. If you really think about it, there are numerous hamstring muscles in the back part of the leg, so you still have many hamstring tendon muscles left, even after you take two.

So, these long tendons basically are such length that you can double them over and still have adequate length to reconstruct the ACL. So, we double them over and then the size of that can fit through a round tube anywhere from six-and-a-half millimeters all the way to eight millimeters in diameter, and really it actually provides more surface area and bulk a graft than say a typical ACL graft, which is a different type of graft. Actually, I'm sorry, I should say an ACL patella tendon graft, which is more of a - it doesn't quite fill up the diameter of a tube. It's more of a flatter graft, although it's quite strong. So, the tendons that we use are those.

The fixation, there's a lot of ways of fixating a hamstring graft. There's basically a point fixation that you can use with screws. You can use pins that go across the bone, and these will go through these or wrapped around these. There are also what we call suspension type fixation, where the graft is looped around a very heavy duty type rope suture and then there's an implant that goes around the end of the bone, and these are implanted around this and are terrifically strong fixation, and then fixed on the other end with either a combination of a screw, a washer, or some type of implant into the tibia. So, the fixation has really developed along the years and now is very strong. In fact, is stronger than that of the patella tendon.