Lower Risk of Revision With Patellar Tendon Autografts Compared With Hamstring Autografts

Background: A number of studies have found comparable results after anterior cruciate ligament (ACL) reconstruction with patellar tendon autografts and hamstring autografts; however, few studies have been large enough to reveal differences in risk of revision with regard to clinical and demographic factors. Purpose: To present the distribution of grafts for ACL reconstruction based on data in the Scandinavian ACL registries and to compare the risk of revision between patellar tendon autografts and hamstring autografts. Potential associations with other clinical and demographic factors were also explored. Study design: Cohort study; Level of evidence, 2. Methods: A total of 45,998 primary ACL reconstructions, including 6736 patellar tendon autografts and 38,666 hamstring autografts, were identified in the Scandinavian ACL registries. The overall median follow-up time was 3 years (range, 0-8 years). To compare the risk of revision between groups of patients, univariate Kaplan-Meier analysis (with log-rank test) and the Cox proportional hazard regression model were applied. The hazard rate ratio with 95% CI was reported as a measure of effect. Results: Patellar tendon and hamstring autografts were used in 14.6% and 84.1% of the patients, respectively. The remaining patients received allografts, direct sutures, or other graft types (1.3%). The primary ACL injury occurred during soccer, team handball, or alpine activities in 67.5% of the patients in the patellar tendon group and 66.2% in the hamstring group. A total of 156 patients in the patellar tendon group and 1042 patients in the hamstring group underwent revision. The overall risk of revision was significantly lower in the patellar tendon group versus the hamstring group (hazard rate ratio = 0.63; 95% CI, 0.53-0.74), and it 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 (P > .05, test for interaction) but seemed to be slightly more pronounced for patients injured during certain pivoting activities (soccer, team handball, and alpine activities) compared with other activities (hazard rate ratio = 0.57 vs 0.81; P = .058, test for interaction). Conclusion: The majority of primary ACL reconstructions in Scandinavia are performed with hamstring autografts. 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.