Articular cartilage is a complex, living tissue that lines the bony surface of joints such as knee joints. Articular cartilage acts as a very thin Shock absorber during daily activities such as walking, stair climbing, and work-related activities.

There are three different types of cartilage are found in the body. Articular or hyaline cartilage (covers joint surfaces), fibrocartilage (knee meniscus, vertebral disk), and elastic cartilage (outer Ear). These different cartilages are distinguished by their structure, elasticity, and strength. In some joints, such as the knee, both articular cartilage and fibrocartilage are found functioning side-by-side, as distinctly different structures with different functions. Articular cartilage forms a thin incrustation upon the joint surfaces of the bones, and its elasticity enables it to break the force of concussions, while its smoothness affords ease and freedom of movement.

It varies in thickness according to the shape of the articular surface on which it lies. When the surface is convex the cartilage is thickest at the center and it becomes thinner on concave surfaces.

The function of articular cartilage is to absorb Shock and provide an extremely smooth bearing surface to facilitate movements of the joints.

Osteoarthritis