Calcification of the Costal Cartilages

Calcification of the costal cartilages is a subject of interest, as, with the possible exception of the pharyngeal cartilages, it is unique in showing ossification taking place throughout adult life. It is shown that contrary to commonly accepted views, the calcification is not perichondral, but is central, and is in the nature of a true ossification. This ossification is unrelated to disease or habitus, though disease may play a part by interfering with the normal blood calcium balance. It is indicated that costal cartilage calcification is a physiological response of a connective tissue to the strains imposed upon it by muscular action, and it is suggested that, in man, the ossification of the rib cartilages may, in fact, be a reaction towards greater rigidity of the anterior chest wall following the assumption of upright posture. The biochemical aspects of ossification are considered, with reference of cartilage calcification in adult life.