The most challenging aspects in treating articular cartilage injury include identifying the cellular and molecular mechanism(s) that lead to matrix changes and the differentiation and dedifferentiation behavior of chondrocytes, and understanding how they affect the structural integrity of the articular cartilage and tissue remodeling. Several treatment strategies have been proposed. A better understanding of the signaling pathways and growth and transcription factors for genes responsible for chondrogenesis is an important component in the development of new therapies to prevent cartilage degeneration or promote repair to replicate the physiologic and functional properties of the original cartilage.