ACL Reconstructions: Which is the Preferred Graft?
Abstract & Commentary
Synopsis: Hamstring tendons are comparable to the patellar tendon in anterior cruciate ligament reconstructions.
Source: Jansson KA, et al. A prospective randomized study of patellar versus hamstring tendon autografts for anterior cruciate ligament reconstruction. Am J Sports Med. 2003; 31(1):12-18.
Patients with anterior knee laxity have been treated with good-to-excellent results with intraarticular ACL reconstructions with autogenous graft material. The most commonly used autogenous grafts are the central third of the patellar tendon (bone-patellar tendon-bone) and the hamstring tendon (semitendinosus-gracilis) constructs. The present study evaluates the difference in outcome between the 2 autografts.
This was a prospective, randomized clinical trial that included 99 patients. Surgery was indicated in an otherwise healthy patient with a clinically diagnosed ACL rupture who experienced instability or wished to maintain preinjury levels of activity. All patients underwent a primary, arthroscopically assisted ACL reconstruction with graft randomization into a patellar or hamstring group according to even or odd birth year. The bone-patellar tendon-bone grafts were fixated with interference metal screws (Linvatec) and the double-looped semitendinosus and gracilis tendons were fixated with a small metal plate (AO, Bern, Switzerland).
Knee function and stability were clinically evaluated preoperatively and at 1 and 2 years postoperatively. Of the 99 patients, 90% were available for 2-year follow-up.
Based on a minimum level of significance of P = .05, Jansson and colleagues found no statistically significant differences preoperatively or postoperatively between the 2 groups with respect to clinical and instrumented laxity testing, International Knee Documentation Committee Score ratings, isokinetic muscle torque measurements, and Kujala patellofemoral, Lysholm, and Tegner scores. Both autografts were shown to result in comparable outcomes 2 years following ACL reconstructions with improvements seen in the patients’ performances.
Comment by Brian J. Cole, MD, MBA, and Nina Shervin
The central third of the patellar tendon and the hamstring tendon are the 2 most commonly used autogenous grafts in ACL reconstructions. It has been reported that the postoperative disadvantages and potential complications of the patellar autograft include patellofemoral pain, weakness of the quadriceps muscle, rupture of the patellar tendon, and patellar fracture. It has also been proposed that potential disadvantages of the hamstring tendon include failure of immediate rigid fixation and lower stiffness relative to the patellar tendon graft or native ACL. Although Jansson et al have recognized the limitations in their study design, including the inability to isolate the comparison to the patellar and hamstring tendons alone as differing fixation techniques were used, they concluded that neither technique had a clear advantage over the other.
Dr. Cole is Assistant Professor, Orthopaedic Surgery, Rush Presbyterian Medical Center, Midwest Orthopaedics, Chicago, IL.