Shallow Medial Tibial Plateau And Steep Posterior Slope: New Risk Factors For Anterior Cruciate Ligament Injury

+Hashemi J; Chandrashekar N; Gill B; Slauterbeck JR; Schutt R; Dabezies, ED;Beynnon BD +Texas Tech University, Lubbock, TX; University of Waterloo, Ontario, CA; University of Vermont, Burlington, VT [email protected] – [email protected] INTRODUCTION Severe knee ligament trauma, such as Anterior Cruciate Ligament (ACL) disruption, is associated with a dramatic loss of function. Even when ACL reconstruction is performed, there is high likelihood that the injury predisposes the knee to the early onset of osteoarthritis, which eventually progresses to end stage disease. This places an emphasis on the prevention of ACL injuries and has focused research on identifying the risk factors that predispose individuals to these debilitating injures. Previous research has identified an inverse relationship between femoral notch width geometry and risk of ACL injury (a decreased femoral intercondylar notch geometry is associated with an increased risk of ACL injury); however, very little is known about the relationship between geometry of the tibial plateau and the risk of suffering an ACL injury. Prior research has shown that the weight bearing regions of the femoral condyles are spherical in profile and symmetrical between medial and lateral compartments. In contrast, the geometry of the tibial plateau varies widely and differs considerably between medial and lateral compartments of the knee. For example, females have significantly increased posterior directed slope of the medial (MTS) and lateral (LTS) tibial slopes. Similarly, the medial tibial depth (MTD) of concavity has been reported to vary widely between male and female subjects. Recognizing that most non-contact ACL injuries occur during landing from a jump when considerable forces and moments are generated across the knee, and the fact that the geometry of the tibiofemoral joint acts to distribute the magnitude and direction of these forces and moments; we hypothesized that subjects with increased posterior directed slope of their tibia while having a shallower medial tibial depth of concavity would be at increased risk of suffering an ACL injury in comparison to those with decreased posterior slope and increased medial tibial depth