Biomechanics and mechanobiology in osteochondral tissues

Osteochondral tissues are those that form the synovial joints, namely cartilage and bone, including sub-chondral bone. The biomechanical purpose of synovial joints is to provide lubricated contact between the moving surfaces with as little frictional forces as possible. This is achieved by separating the cartilage layers by a thin film of fluid and supporting the cartilage layers by a bony trabecular network that becomes dense and more calcified immediately underneath the cartilage layer. Each tissue's biomechanical behavior is well understood after several decades of research and this behavior is briefly reviewed here, as are the concepts relating to the mechanical induction of cartilage degradation (osteoarthritis) with a discussion of clinical strategies for repair. Focusing on tissue-engineering strategies, the following concepts are reviewed: scaffolds, bioreactors and computational simulations, with an analysis of how these elements may be combined in future.