The ACL has irregular and complex geometry; therefore, the ideal element type for ACL simulation is the 10-node tetrahedral element SOLID187. It is well suited to modeling irregular geometries (such as those created using CAD/CAM systems).

The fiber directions in the ACL can be defined using the vectors (A,B) in the anisotropic hyperelastic material model. The ligaments are highly anisotropic because of their strongly unidirectional fibrous structure and provide primary resistance to the tensile loading; therefore, only the direction vector aligned with the long axis is considered.

Although a simplified model of ACL is used in this problem, femur and tibia sides with insertion zones can also be considered in an ACL simulation. In such a case, a fine mesh yields more accurate results. Too fine a mesh, however, increases computational time; to minimize the computational cost, the femur and tibia sides can be considered to be rigid.