Fibrous structures in augmentation for rotator cuff repair: an experimental comparison

Abstract

Background and purpose. Rotator cuff tendon (RCT) injuries are difficult to manage as current strategies do not restore tissue functionality. Driven by this market demand, several devices have been developed during the last years, however, to develop a structure that properly mimics the mechanical performance of the native tissue remains a challenge. This way, in this work we study a set of design criteria for a synthetic graft development for RCT repair and reconstruction, in order to achieve a structure with an adequate mechanical performance to substitute the damaged tissue, and that can also act as a scaffold, allowing and guiding tissue ingrowth. Materials and Methods. Two three-dimensional (3D) and two planar (2D) warp-knitted structures were developed using polyethylene terephthalate (PET) yarn, and are characterized in terms of their morphology, absorption and wicking behavior, and mechanical properties. Results. The present warp-knitted structures mimic the non-linear mechanical behavior of the native tissue. A less porous planar structure was concluded to be the best to provide mechanical augmentation, as it demonstrated mechanical properties suitable for RCT repair. Pre-tensioning techniques were adequate to increase this type of textile’s mechanical properties. Furthermore, the physical properties of this structure can allow and guide tissue ingrowth, demonstrating its potential to act also as a scaffold. Conclusions. As this is a relatively new field of application of knitting technologies, this work provides important information on how a warp-knitted structure should be tailored and treated post-production, in order to be used for RCT repair.