Topologically controlled tensile behaviour of braided prostheses for anterior cruciate ligaments.

Anterior cruciate ligament (ACL) is one of the most susceptible ligaments of the knee that can suffer injury. These ruptured ligaments can be treated through surgical intervention using a braided structure that either acts as a substitute graft in isolation or an augmentation device alongside the biological tissue. Therefore, the main objective of the research work is to present an analytical model for predicting the complete set of tensile properties of braided prosthesis consisting of multifilament strands based upon predefined braid geometry and constituent material properties. The model has also accounted for the kinematical changes under defined loading conditions. The research findings have been confirmed by making a comparison between the theoretical and experimental results. The tensile properties of braided prostheses predicted via analytical route matched reasonably well with the experimental results.

Tensile behaviour of structurally gradient braided prostheses for anterior cruciate ligaments.

Anterior cruciate ligament (ACL) is a key fibrous connective tissue that maintains the stability of a knee joint and it is the most commonly injured ligament of the knee. A synthetic prosthesis in the form of a braided structure can be an attractive alternative to biological grafts provided that the mechanical properties can be tailored to mimic the natural ACL. In the present work, the polypropylene based structurally gradient braided prostheses have been designed and developed by understanding their tensile properties. Circular braiding process was employed to fabricate structurally gradient braided prostheses by systematically placing different types of braids in defined set of layers. An analytical model for predicting the tensile properties of structurally gradient braided prostheses has been presented by modifying and combining the existing models available in the literature. Specifically, the full set of stress-strain behaviour of structurally gradient braided prostheses has been computed based upon braid structural characteristics, constituent strand properties and braid kinematics. A triaxial braid in the outer layer of braided prostheses was found to withstand higher tensile stresses in comparison to a biaxial braid having same structural characteristics. A comparison has been made between the theoretical and experimental results of tensile properties of structurally gradient braided prostheses. The tensile properties of structurally gradient braided prostheses predicted through analytical route matched reasonably well with the experimental results.

Geometrically controlled tensile response of braided sutures.

Sutures are the materials used for wound closure that are caused by surgery or trauma. The main pre-requisite to the success of the suture is to obtain ultimate level of tensile properties with defined geometrical constraints. In this communication, the model for tensile properties of braided sutures has been proposed by elucidating the most important geometrical and material parameters. The model has accounted for the kinematical changes occurring in the braid and constituent strand geometries under defined level of strain. A comparison has been made between the theoretical and experimental results of stress-strain characteristics of braided sutures.