Costal cartilage bridges the sternum and the ribs and plays a key role in the biomechanics of the chest. Costal cartilage is known to calcify in local regions with age, which can substantially stiffen its overall response to loading. However, the rate of accumulation of the calcified volume is not well quantified. Current computational models of the thorax assign a homogeneous soft material to cartilage segments, yet their finite element meshes are well suited to the specification of interstitial calcification zones, should applicable data become available.

This study measures volumes and extents of costal cartilage calcification from 205 live subject CT scans. Significant increases in volume calcification – both in a given cartilage segment and in the lengthwise extent of those segments that experience calcification – are seen with age (p<0.0001). Age and sex accounted for 35% of all inter‐individual population variability. Specific recommendations for introducing person‐age via regional calcification to models of the costal cartilage are that (1) calcification volume within a segment should increase at the rate of 0.9 mm (for an equivalent cube edge length) per decade, and (2) should involve an increasing lengthwise extent of the cartilage segment at a rate of at least 7% per decade.