Articular cartilage, the resilient durable tissue that forms the opposing articulating surfaces of synovial joints, provides these surfaces with the lowfriction, lubrication, and wear characteristics that make possible smooth painless movement.

It also absorbs mechanical load and spreads these applied loads onto subchondral bone. No synthetic or reparative material performs as well as a natural joint surface. Injuries or diseases of articular cartilage cause pain and loss of mobility for more people than disorders of any other musculoskeletal tissue. This chapter reviews current understanding of how the unique structure and composition of articular cartilage give the tissue its remarkable mechanical properties and durability. It also introduces the subjects of articular cartilage injury and repair.