Extracellular matrix scaffold devices for rotator cuff repair

Rotator cuff tears affect 40% or more of those over age 60, and the repair failure rate of large to massive tears ranges from 20 to 90%. High re-tear rates are a result of mechanical factors as well as biologic factors that may compromise the patients' intrinsic capacity to heal. Hence, there is a critical need for repair strategies that provide adequate strength as well as stimulate and enhance healing potential. Tissue engineering strategies to improve rotator cuff repair healing include the use of scaffolds, growth factors, cell seeding or a combination of these approaches. Scaffolds have been the most common strategy investigated to date. Despite the growing clinical use of scaffold devices for rotator cuff repair, there are numerous questions related to their indication, surgical application, safety, mechanism of action and efficacy that remain to be clarified or addressed. The purpose of this paper is to review the current basic science and clinical understanding of extracellular matrix scaffolds, which are currently the most widely used scaffolds for rotator cuff repair. Our review will emphasize the host immune response and scaffold remodeling, the mechanical and suture retention properties of ECMs and preclinical and clinical studies on the use of ECMs for rotator cuff repair. We will then discuss the implications of these data on the future directions for use of these scaffolds in tendon repair procedures.