The articular cartilage caps the ends of all the long bones and is an essential structure in all diarthrodial Joints. Its homogeneous macroscopic appearance belles its enormous complexity microscopically. It functions as a complicated shock‐absorbing and low friction‐bearing surface. In a clinical context, the ability of the athlete to jump and to absorb large compressive forces as well as to run with smooth, low friction oscillations depends on these functions. Despite major advances in ligament and meniscal treatment, the outcome of a significant knee joint Injury may depend solely on the subsequent function of the articular cartilage. Many clinical syndromes are associated with“destabilization”; of this structure, but our ability to diagnose and treat these Injuries is limited.