Mechanical testing of anterior cruciate ligament grafts

Injury to the anterior cruciate ligament (ACL) of the knee is common in both recreational and competitive athletes. Complete tears of the ACL do not heal, therefore surgeons have turned to autografts and allografts in an attempt to recreate the function of the intact ACL. Choice of graft material and graft-fixation device are highly debated topics. This article provides a brief description of some basic biomechanical principles followed by a discussion of the application of these concepts to the evaluation of various ACL replacement grafts and ACL graft-fixation devices. The functional behavior of normal, ACL-deficient, and ACL-reconstructed knees under various external loading conditions is also discussed. The information presented in this article should provide an understanding of biomechanical factors that can aid surgeons in choosing the appropriate graft and graft-fixation construct for their patients.