Therefore, it was hypothesized that trends in tensile properties would reflect trends in collagen content. In this study, collagen content was quantified in each tissue and normalized to tissue wet weight. It was found that the menisci had the highest collagen content, followed by the patellar ligament and the collateral ligaments. Collagen content was lowest in the hyaline cartilages and the cruciate ligaments. As expected, the tensile properties appear to reflect the general trends observed in collagen content normalized to wet weight. In particular, it was found that the menisci and patellar ligament exhibited significantly higher stiffness and strength values compared to the other tissues, while the hyaline cartilages and the cruciate ligaments were among the softest and weakest in tensile properties. The differences in tensile properties among the ligament tissues may reflect the anatomical development of these tissues, since the stiffer/ stronger tissues are extracapsular ligaments, and the softer/ weaker tissues are intracapsular ligaments. In particular, the patellar ligament arises from fibers of the quadriceps muscle attaching inferiorly to the tibial tuberosity, hence the term ����patellar tendon���� often used interchangeably with patellar ligament, given the tendinous origin; the cruciate ligaments develop posteriorly from the articular interzone; and the collateral ligaments form independently of the joint capsule or from mesenchymal condensation in the joint capsule . Furthermore, of particular interest was the finding that CraCL is significantly softer and weaker than CauCL. Future studies should seek to examine whether this relationship is maintained in adult cows, as well as whether it is observed in humans. Taken together, the tensile data described above contribute important Abmole Streptozotocin information about the tensile properties of immature tissues, especially in light of the increasing incidence of knee joint injuries among youths. Additionally, these tensile properties may serve as important benchmarks to determine success criteria for in vitro engineering of the major knee joint connective tissues, all of which play important roles in mechanical function. Tissue engineering efforts aimed at recapitulating native tissue structures should strive to reproduce native tissue biomechanical properties, as well. Crosslink analysis with HPLC showed that the different joint tissues had varying pyridinoline abundances that contributed to tensile stiffness. The data showed that the hyaline cartilages and the cruciate ligaments exhibited the highest pyridinoline levels. Both the patellar ligament and CauCL exhibited higher tensile stiffness values that paralleled pyridinoline content but not the amount of collagen. Although pyridinoline has been shown to correlate with tensile strength and stiffness in bovine articular cartilage, this is the first study to show that pyridinoline also contributes to the mechanical properties of other joint tissues. These results also corroborate structurefunction relationships in other species. For example, a study of the rat tendon demonstrated that pyridinoline was a better indicator of ultimate stress than collagen content. These structure-function relationships illustrate the importance of crosslinking in a variety of joint tissues. Pyridinoline content is known to generally increase as tissues matures, but this study provides comprehensive, quantitative benchmarks that can be compared to adult tissue values.