Cartilage repair: third-generation cell-based technologies--basic science, surgical techniques, clinical outcomes.

The goal of all cartilage replacement techniques is the reformation of mature organized hyaline cartilage. However, currently cartilage repair techniques lead principally to production of fibrocartilage, which has material properties that are inferior to hyaline cartilage. Cell-based therapies such as autologous chondrocyte implantation hold promise for cartilage regeneration; however, these techniques still do not predictably result in hyaline cartilage formation. The newest, "third-generation techniques" have been developed to address the limitations of earlier techniques. These new procedures use 3 novel approaches: chondro-inductive or chondro-conductive matrix; use of allogeneic cells, both of which may allow a single-stage surgical approach; and techniques to mechanically condition the developing tissue before surgical application to improve the material properties and maturation of the implant. However, at this time there is very limited clinical data available on the nature and outcomes of these procedures.