Experimental Search for Determinants of Ligament Health

The anterior cruciate ligament (ACL) is one of the four ligaments which stabilize the knee during movement. Today, ACL injury is on the rise, occurring more than 200,000 times per yearmost often in agility sports. With so many people affected by ACL injury, the medical community stands to benefit from an understanding of the observable attributes which characterize ligament health. Such an understanding would allow standard MRI screenings to be utilized in determining a patients susceptibility to ligament damage and detecting damage which has occurred prior to tearing. This study aims to relate ligament composition and microstructure observed in MRI with ligament health characterized by mechanical testing. For this, a porcine knee was used and T2 and T1 MRI data was obtained prior to mechanical testing. The specimen was then dissected to leave only the femur-ACL-tibia complex intact. The femur and tibia were potted into fixtures which mount to the base and crosshead of a load frame. An auxiliary load cell was used to record force data, while a motion capture system tracked the ACLs length during testing. Elastic tensile testing was used to measure stiffness. Current work includes sensitivity analysis of the transformation from the stiffness data to the elastic modulusa material property of ligaments. This will be compared to the samples MRI data, which characterizes composition and microstructure. Repeating this procedure for many samples will reveal underlying correlations between ACL health and composition.Ope