Initial Biomechanical Properties of Anterior Cruciate Ligament Reconstruction Autografts

ABSTRACT: To provide more information to consider when selecting a reconstruction  technique, we did a side-by-side comparison of some of the initial biomechanical properties of  currently accepted reconstruction methods. Our research hypotheses were that a quadrupled,  woven semitendinosus and gracilis graft is as strong as any of the other commonly used graft  materials and that quadrupling and weaving the hamstring graft may increase the stiffness of  the overall construct. Using lower extremity cadaveric specimens harvested from young    donors, we fashioned seven each of seven types of graft: 9-mm, 10-mm, and 11-mm-wide  patellar tendon graft (PTG); 10-mm-wide central quadriceps tendon graft; doubled  semitendinosus graft; tripled semitendinosus graft; and quadrupled, woven semitendinosus and gracilis graft. Specimens were stripped of remaining soft tissue, and anterior cruciate  ligament (ACL) constructs were created for biomechanical testing. The tibia was translated  anteriorly on the femur, mimicking a pivot shift maneuver, and failure strength, failure  mechanism, and construct stiffness were recorded. No differences in mean strength were detected. The quadrupled, woven graft was significantly stiffer than the doubled  semitendinosus graft and no less stiff than any of the PTG constructs. All grafts showed similar A nd adequate initial absolute strength to reconstruct the ACL. Quadrupling and weaving the
semitendinosus and gracilis graft increases the stiffness of the reconstructed specimen to a level statistically similar to that of specimens reconstructed with a PTG.