Anterior cruciate ligament (ACL) tears have a high rate of occurrence, debilitating symptoms, arduous recovery process, and economic impact that necessitate improved injury prevention programs and clinical treatment. Patient-specific care has improved clinical outcomes and additional individualized measures are needed. Tibiofemoral bony morphology impacts knee mechanics by influencing knee motion through bone-to-bone articulation. Therefore, determining tibiofemoral bony morphological risk factors for ACL injuries and their influence on knee mechanics would provide clinicians with parameters to individualize injury prevention and treatment. The objective of this dissertation is to provide a better understanding of tibiofemoral bony morphological risk factors for ACL injury and their effect on knee mechanics before and after injury and treatment.

Using statistical shape modeling, a smaller anterior-posterior length of the tibial plateau, a greater angle between the femoral long axis and femoral condylar axis, and a more lateral mechanical axis of the distal femur were determined to associate with ACL injuries compared to uninjured subjects. No differences were determined between the ACL injured knee and the contralateral knee of the ACL injured subject demonstrating their knees are at equal risk for injury. A computational model of the knee used this data to predict that smaller anterior posterior length of the tibial plateau and more lateral mechanical axis resulted in greater force in the ACL in response to an anterior drawer at 30° and 60° of flexion. Functional bracing was also found to provide additional rotatory stability to the knee and decreased the force in the ACL in response to a simulated pivot shift at lower flexion angles using a cadaveric model. These findings demonstrate that functional braces can reduce ACL injury risk. Tibiofemoral bony morphological features were also correlated with knee kinematics and kinetics before and after application of a brace and lateral extraarticular tenodesis demonstrating that certain morphological features influence the impact of each treatment option. Overall, tibiofemoral bony morphological features are risk factors for ACL injury, influence knee mechanics differently after injury and treatment, and impact biomechanical behavior of the knee. Implementing individualized programs that account for these morphological features may result in better clinical outcomes.