Effect of Age on the Biomechanical Properties of Porcine LCL

The Lateral Collateral Ligament (LCL), one of the four major ligaments in the knee joint, resides on the outer aspect of the knee. It forms a vital connection between the femur and the fibula. The LCL's primary role is to provide stability against Varus forces, safeguarding the knee from undue rotation and tibial displacement. Uniaxial mechanical testing was conducted on the dog bone (DB) samples in this study. The porcine of different ages, from 3 months to 48 months (4 years) old, were used to analyse the effect of age. A constant head speed of 200 mm/s was applied throughout the tests to mimic strain-stress and damage responses at an initial strain rate of 13.3/s. The mechanical properties of LCL were evaluated, with a specific focus on the effect of age. The LMM (Linear Mixed Model) analysis revealed a marginally significant positive slope for Young's modulus (<i>p</i> = 0.0512) and a significant intercept (<i>p</i> = 0.0016); for Maximum Stress, a negative slope (<i>p</i> = 0.0346) and significant intercept (<i>p</i> < 0.0001); while Maximum Stretch showed a significant negative slope (<i>p</i> = 0.0007) and intercept (<i>p</i> < 0.0001), indicating the muscle reduces compliance and load-bearing capacity with age.