Reproduction of the Mechanical Behavior of Ligament and Tendon for Artificial Joint Using Bioinspired 3D Braided Fibers

The level of joint laxity, which is an indicator of accurate diagnosis for musculoskeletal conditions is manually determined by a physician. Studying joint laxity via artificial joints is an efficient and economical way to improve patient experience and joint proficiency. However, most of study focus on the joint geometry but are inadequate with regard to the tailored mechanical properties of soft tissues. On the basis of collagen fibril deformation, this study proposes bioinspired 3D fibers braided from polyethene multifilament for the reproduction of the controlled nonlinear behavior of ligaments and tendons. Four braided bands are designed, all showing biological behaviors. Two knot-based bands exhibit large toe strains of 10.98% and 5.33% but low linear modulus of 239.84 MPa and 826.05 MPa. The other two bands without knots exhibit lower toe strains of 1.61% and 1.52% but high linear modulus of 2605.27 MPa and 2050.74 MPa. Empirical formulas for braiding parameters (wales and courses) and mechanical properties are expressed to provide a theoretical basis for the mimicry of different tissues in the human body by artificial joints. All parameters have significant effects on the linear region of the load-displacement curve of a fiber due to braided structure, while changing the number of wales facilitates a major contribution to the toe region. A biofidelic human knee has been successfully reconstructed by using bioinspired 3D braided fibers. This study demonstrates that the nonlinear mechanical properties of soft tissues can be replicated by bioinspired 3D braided fibers, further yielding the design of more biomechanically realistic artificial joints.