Biaxial Mechanics of Musculoskeletal Tissue and Fiber-Reinforced Scaffolds

Biaxial tensile testing is the primary experiment used to functionally evaluate cardiovascular fiber-reinforced tissues [1, 2], but has not been widely applied to musculoskeletal tissues. The in situ geometry of many musculoskeletal tissues does not meet uniaxial tensile boundary conditions of freely contracting edges and large aspect ratios. In addition, biaxial tests load the sample through a larger domain of strain configurations as are experienced in situ. In contrast, uniaxial tests represent just a single path within that domain. It has been shown in cardiac tissue and grafts that model parameters determined from biaxial experiments can be used to predict uniaxial behavior, but that uniaxial tests do not predict the biaxial behavior well [1, 2]. Therefore, biaxial mechanical testing is important to address musculoskeletal tissue function.