The shear behaviour of the rabbit medial collateral ligament.

This study was conducted to determine whether load is transmitted via shear through the matrix between ligament fibres rather than solely as tension in the fibres. Thirty-six rabbit medial collateral ligaments were subjected to uniaxial tension tests. Twenty-four of these ligament complexes were incised laterally to create longitudinal shear planes, while the remaining 12 complexes served as controls. Data were used in conjunction with finite element models to determine how shear transfer, if any, occurred in the ligament. Non-linear, anisotropic, plane stress finite element models were able to simulate the non-linear structural behaviour shown by uncut control ligaments under normal tensile testing. The finite element models were also able to reproduce the ligament load deformation behaviour observed in the shear tests. Results indicated that some load was transferred between the collagen fibres and other constituents in the ground substance of these ligaments and possibly also through fibres missed during the cutting procedure. The exact manner in which the load was transmitted remains unclear and requires further investigation and quantification.