We have recently been seeing an increase in new patients that suffered an ACL injury while skiing, unfortunately, their injury required them to have ACL surgery. A question I often get asked by patients during the rehab process is, “Did I choose the right ACL graft?" Overall, that is a great question and in this blog, I will talk about 3 different ACL grafts I see most often.
As a quick reminder, the ACL acts as a major stabilizer for the knee joint, and if it becomes torn, instability, weakness, and discomfort are sure to follow. The three most common ACL grafts I see are Hamstring, Patellar, and Cadaver. Not to confuse you but you can have a cadaver graft of the hamstring or patellar, we refer to that as an allograft meaning you are using someone else’s tissue, whereas an autograft means you are using your own tissue.
Below I will talk about the three main grafts and list a few pros and cons for both.
Three Common Types of ACL Grafts
Patella Autograft
This graft is harvested from the patient where the doctor removes a strip of tissue in the middle of the patella tendon before weaving it into a band to act as your new ACL. Historically patella tendon grafts have less rate of failure and are stronger grafts. In fact, studies have shown that the patella tendon graft is 70% stronger than a normal ACL graft at the time of surgery. One of the biggest issues you will see following a patella graft is patella tendonitis due to the weakening of the tendon as a result of harvesting tissue from that tendon. Overall, this is a minor issue that clears up with hands-on care, and continued education by your therapist to improve pain-free movement patterns while strengthening the surrounding weakened tissue/muscle.
Hamstring Autograft
A hamstring autograft is obtained from the patient, harvesting the tendon tissue from 2 of the medial hamstrings (semitendinosus, and semimembranosus). The pros for this graft are that gaining knee extension comes quicker, lower incidence of post-surgical arthritis, and decreased knee pain for those individuals who are required to kneel a lot for work, home, or recreational activities. A few of the cons for this graft is the need to rehabilitate to sites again as the hamstring has been weakened due to harvesting tissue from the area. Additionally, the graft can be weaker than a patella tendon graft due to the surgical protocol of using implants to adhere to the graft, instead of in the patella tendon graft where bone plugs are used to attach the tendon.
Cadaver Graft (Allograft)
As the name implies this graft came from someone else with the tissue being harvested from the hamstring, Achilles, patella, or quadriceps of another individual. A major pro of this type of graft is that rehab processes will go quicker due to you don’t have to rehabilitate two surgical sites. A big issue that I’ve read about and seen is that the graft can become weakened following sterilization of tissue leading to a higher failure rate compared to the patella or hamstring graft. In fact, a recent study referenced as the MOON study found that the failure rate in young people was four times higher compared to using the patient's own tissue.
Which graft is right for you? Well, it really all comes down to you and your surgeon’s preference.
I hope this article gives you a little clarification on the different grafts available in case you are ever in need of ACL surgery.