Bone-patellar tendon-bone grafts for anterior cruciate ligament reconstruction - An in vitro comparison of mechanical behavior under failure tensile loading and cyclic submaximal tensile loading

Background: Secure fixation is an important factor in the success of anterior cruciate ligament reconstruction. Hypothesis: There is no difference in the mechanical behavior of reconstructions from method of fixation or method of testing. Study Design: Controlled laboratory study. Methods: Anterior cruciate ligament reconstructions were performed with bone-patellar tendon-bone grafts in 48 human cadaveric knees. Three different fixation methods (Endobutton, interference screw, suture-post fixation) were compared under failure tensile loading and cyclic submaximal tensile loading. Results: No difference was observed in ultimate load among the three techniques. Stiffness of the grafts was significantly lower for the suture technique than for the interference screw technique. Cyclic loading revealed significantly different failure rates: 0% of the Endobutton, 38% of the interference screw, and 100% of the suture-post groups. The relative movement of the femoral bone plug and the migration of the bone plug out of the femoral canal were lowest in the interference screw group. Conclusions: The suture-post fixation is not recommended. The interference screw technique showed the best results, but results were age-dependent, suggesting its best use is in younger patients. The Endobutton technique is recommended for older patients. Clinical Relevance: Results of testing are useful to the surgeon in making a choice of reconstruction technique, (C) 2002 American Orthopaedic Society for Sports Medicine.