Patellar Tendon Graft Results in Fewer ACL Revisions

Anterior cruciate ligament (ACL) reconstruction with a patellar tendon autograft returns better results than those with a hamstring autograft, according to a new study.

Researchers at St. Olav’s Trondheim University Hospital (Norway), the Norwegian University of Science and Technology (Trondheim, Norway), and other institutions reviewed the Scandinavian ACL registries to compare the risk of revision between patellar tendon autografts and hamstring autografts. In all, 45,998 primary ACL reconstructions, including 6,736 patellar tendon autografts and 38,666 hamstring autografts were identified, with a median follow-up time of three years. During that time, 156 patients in the patellar tendon group and 1,042 patients in the hamstring group underwent revision.

The results showed that the overall risk of revision was significantly lower in the patellar tendon group than in the hamstring group, and decreased with increasing age at surgery, although not strictly linearly. The lower risk of revision in the patellar tendon group was consistently observed across subgroups of patient sex, age, and concomitant cartilage injury, but seemed to be slightly more pronounced for patients injured during certain pivoting activities, such as soccer, team handball, and alpine activities, when compared with other activities. The study was published on September 8, 2014, in the American Journal of Sports Medicine.

“The majority of primary ACL reconstructions in Scandinavia are performed with hamstring autografts,” concluded lead author Tone Gifstad, MD, PhD, of St. Olav’s. “Results from the present large prospective study show that patients receiving patellar tendon autografts have a statistically significantly lower risk of revision compared with patients receiving hamstring autografts.”

ACL reconstruction can be done with several different graft choices. These most common options include patellar tendon, hamstring tendon, and donor tissue (allograft). When a patellar tendon graft is selected, the central 1/3 of the patellar tendon is removed, along with a block of bone at the sites of attachment on the kneecap and tibia. The patellar tendon graft closely resembles the torn ACL, and allows for "bone to bone" healing, considered to be stronger than other healing methods. The most common problem following ACL surgery using the patellar tendon is pain over the front of the knee.

When the hamstring tendons are used in ACL surgery, two of the tendons of these muscles are removed, and "bundled" together to create a new ACL. The incision to obtain the graft is smaller, and the pain both in the immediate postoperative period, and down the road, is thought to be less. The primary problem with these grafts is the fixation of the graft in the bone tunnels; with the hamstring grafts, a longer period of time is necessary for the graft to become rigid.

Related Links:
St. Olav’s Trondheim University Hospital
Norwegian University of Science and Technology