Tension-torsion characteristics of the canine anterior cruciate ligament- Part II: Experimental observations

An experimental program was devised to determine whether the canine anterior cruciate ligament with an apparent helical twist of its component fiber bundles could support a torque during axial loading to failure. The experimental axial force data was used to determine material parameters in the constitutive equation for the fascicle and underlying bone. A nonlinear ligament model based on this response was found to reproduce the axial force data adequately and to reasonably predict the observed ligament torque over the entire subfailure loading range.