Cartilage as the cricoid cartilage and carina. Cartilage is composed of specialized cells called chondrocytes that produce a large amount of collagenous extracellular matrix, abundant ground substance that is rich in proteoglycan and elastin fibers. Cartilage is classified in three types, "elastic cartilage", "hyaline cartilage" and "fibrocartilage", which differ in relative amounts of collagen and proteoglycan. Cartilage does not contain blood vessels (it is avascular) or nerves (it is aneural). Nutrition is supplied to the chondrocytes by diffusion. The compression of the articular cartilage or flexion of the elastic cartilage generates fluid flow, which assists diffusion of nutrients to the chondrocytes.
Articular cartilage damage but their use is still expensive and time consuming. X-rays show only bone injuries and are therefore not very helpful in diagnosing cartilage damage, especially not in early stages. The best tool for diagnosing articular damage is the use of arthroscopy. The International Cartilage Repair Society has set up an arthroscopic grading system by which cartilage defects can be ranked: Doctors will often also measure the size of each defect. Defects smaller than 2 cm, for example, are considered to be small. It is also important to remember that although the amount of damage is an important factor, the location