A new device to measure the structural properties of the femuranterior cruciate ligament-tibia complex

Previous studies of biomechanical properties of femur-anterior cruciate ligamenttibia complex (FATC) utilized a wide variety of testing methodologies Introduction The anterior cruciate ligament (ACL) has a very complex anatomy which enables it to perform an important role in guiding knee motion. As the knee undergoes flexionextension, internal-external, and varus-valgus rotation, the length and orientation of the ACL change significantly. The broad attachments of the ACL to both the femur and the tibia allow various portions of the ligament to be relatively taut throughout a full range of knee motion. So, given a particular orientation of the knee, some collagen bundles of the ACL experience tension while other bundles are unloaded Previous studies of the biomechanical properties of the femur-ACL-tibia complexes (FATC) utilized knee orientations and loading directions which were poorly documented and seemingly arbitrary with respect to the ligament orientation relative to the direction of applied load. Thus, data are difficult to compare with one another. Viidik [5] investigated the structural properties of the FATC in rabbits with the knee in a fully extended position and with the femur, tibia, and ACL all aligned along the axis of the applied tensile load. Gupta et al. [6] used a similar experimental set up to test the FATC of canines, but with the tibia externally rotated 90 deg relative to the femur to eliminate the natural twist in the ACL. Noyes and Groo