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Defining the Challenge: The Basic Science of Articular Cartilage Repair and Response to Injury

The repair of articular cartilage is an area of orthopedic research that has seen explosive growth over the past ten years. Researchers who had previously disregarded cartilage repair because of its poor intrinsic reparative capability have changed their outlook with the advent of new technologies. Our review examines the damage of cartilage and its response on a cellular level. There is an overview of some new methods that are being used to modulate the repair of articular cartilage through different perioperative techniques, the use of gene therapy, utilization of various growth factors such as transforming growth factor-beta, insulin-like growth factor, and bone-morphogenic proteins; also the use of new bioactive materials such as chyrsalin, platelet rich plasma, and processed marrow is reviewed. We describe the different types of scaffolds being studied. In conclusion we examine issues that will be important for future study such as the use of proper in vivo models and further discuss some of the more controversial areas of research such as the use of hyaluronic acid, postoperative immobilization, and careful retention of the subchondral plate for successful outcomes.