Measurement of the mechanical properties of the ovine anterior cruciate ligament bone-ligament-bone complex: a basis for prosthetic evaluation.

The reported ultimate tensile stress of the anterior cruciate ligament varies greatly, ranging from 13 to 147 MPa. This study shows that the orientation and degree of flexion of the bone-ligament-bone complex significantly alter the apparent ultimate tensile properties (ultimate tensile stress ranging from 60 +/- 3 to 123 +/- 15 MPa, ultimate specific extension from 37 +/- 7 to 93 +/- 20%), whilst the method chosen for measuring extension also affects the calculated specific extension of the bone-ligament-bone complex. It is suggested that, for considerations of prosthesis design and evaluation, the mechanical properties of the bone-ligament-bone complex should be measured in anterior draw and extension measured using points as close as possible to the positions of the ligamentous attachment sites.