In this Section
ACL Reconstruction Grafts
Patellar Tendon Graft
The patellar tendon is a flat, broad tendon with bone attached to both ends. The central third of the tendon can be used along with bone plugs from the patella and tibia for reconstruction of the anterior cruciate ligament, ACL.
This graft has a very long track record and has been considered the gold standard for ACL reconstruction. The advantages of this graft include: increased stiffness of the tendon and ability to achieve ridged initial fixation due to the bone plugs on each end of the graft. The patellar tendon graft allows for early bone-to-bone healing, which is crucial for ACL reconstruction.
The patellar tendon graft has historically had the best long-term results in terms of stability. It has also been shown to have a mean strength that is approximately 168% of the normal ACL. The procedure has been associated with anterior knee discomfort in some patients. However, the benefits of the graft far outweigh the risk of slight knee discomfort.
Hamstring Tendon Graft
The hamstring tendons can also be used as a graft for ACL reconstruction. There are four hamstring tendons in the body. Typically two tendons, the gracillis and semitendinosous tendons are used for the ACL graft. These two tendons are doubled over to create a four-stranded graft. Biomechanically, the hamstring graft itself is actually stronger than patellar tendon graft.
Unlike the patellar tendon graft, the hamstring graft does not involve bone. This means the fixation methods can vary, but the injury can still be fixed arthroscopically. This also means there is no bone-to-bone healing, but rather soft tissue-to-bone healing.
Hamstring grafts have several potential advantages including, smaller incisions, less anterior knee pain, and less likelihood of patellar tendonitis. The disadvantage of hamstring grafts as compared to patellar tendon graft is that the tendons may stretch out more over time. This can cause hamstring tendinitis and weakness.
For ACL tears, allograft tissue is commonly used. The tissues used include, the patellar tendon allograft, the achilles tendon allograft, and the hamstring tendon allograft. Allografts have been shown to provide stable fixation after ACL reconstruction. They are often used in multi-ligamentous injuries (multiple ligament injuries), in revision surgeries, and in patients looking for a quicker recovery or less donor site pain.
Concerns with allograft have included disease transmission (which is extremely rare), swelling, and laxity. No tissue matching is required for allograft ACL reconstruction.