THE HUMAN POSTERIOR CRUCIATE LIGAMENT COMPLEX - AN INTERDISCIPLINARY STUDY - LIGAMENT MORPHOLOGY AND BIOMECHANICAL EVALUATION

To study the structural and functional properties of the human posteri or cruciate ligament complex, we measured the cross-sectional shape an d area of the anterior cruciate, posterior cruciate, and meniscofemora l ligaments in eight cadaveric knees. The posterior cruciate ligament increased in cross-sectional area from tibia to femur, and the anterio r cruciate ligament area decreased from tibia to femur. The meniscofem oral ligaments did not change shape in their course from the lateral m eniscus to their femoral insertions. The posterior cruciate ligament c ross-sectional area was approximately 50% and 20% greater than that of the anterior cruciate ligament at the femur and tibia, respectively. The meniscofemoral ligaments averaged approximately 22% of the entire cross-sectional area of the posterior cruciate ligament. The insertion sites of the anterior and posterior cruciate ligaments were evaluated . The insertion sites of the anterior and posterior cruciate ligaments were 300% to 500% larger than the cross-section of their respective m idsubstances. We determined, through transmission electron microscopy, fibril size within the anterior and posterior cruciate ligament compl ex from the femur to the tibia. The posterior cruciate ligament become s increasingly larger from the tibial to the femoral insertions, and t he anterior cruciate ligament becomes smaller toward the femoral inser tion. We evaluated the biomechanical properties of the femur-posterior cruciate ligament-tibia complex using 14 additional human cadaveric k nees. The posterior cruciate ligament was divided into two functional components: the anterolateral, which is taut in knee flexion, and the posteromedial, which is taut in knee extension. The anterolateral comp onent had a significantly greater linear stiffness and ultimate load t han both the posteromedial component and meniscofemoral ligaments. The anterolateral component and the meniscofemoral ligaments displayed si milar elastic moduli, which were both significantly greater than that of the posteromedial component.