Cartilage mainly includes elastic cartilage, hyaline cartilage and fibrocartilage, as follows: 1. Elastic cartilage: mainly distributed on the surface of the bone joints, forming the osteoarticular surface, the patient will protect the joint and maintain the normal function of the joint through elastic cartilage during weight-bearing activities. With age, the elastic cartilage will degenerate and the subchondral bone will be exposed, and the patient will experience degenerative osteoarthritis, which will lead to joint pain and joint deformity. Therefore, the elastic cartilage should be protected as much as possible to avoid accelerated joint degeneration.2. hyaline cartilage: distributed in the trachea and bronchial wall, forming a local scaffold to avoid tracheal collapse and maintain normal ventilation.3. fibrocartilage: mainly distributed in the spine at the location of the intervertebral discs, protecting the nucleus pulposus tissue, once a fracture occurs, the nucleus pulposus will protrude and form a herniated disc to compress the nerve.