AnatomyThe costal cartilages are extensions of hyaline cartilage from the anterior ends of the ribs and contribute to the elasticity of the thoracic wall ( Fig. 43.1). Each of the 12 paired ribs articulate posteriorly with the respective thoracic vertebrae. Anteriorly, the first seven pairs of ribs, also known as true ribs, attach directly to the sternum through their respective costal cartilages. Typically the costal cartilages of ribs six and seven have an intercostal attachment. The remaining five pairs of ribs (8 through 12) either have an indirect attachment or no attachment to the sternum, and are known as the false ribs. 8,9,10 Conventionally, the costal cartilages of ribs 8, 9, and 10 are described as being attached to the costal cartilages of ribs 7, 8, This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.