People with Pectus do not have an overgrowth of costal cartilage

Updated: Jun 21, 2020

The most common explanation for why people with pectus excavatum have an indent in their chest is an overgrowth of costal (chest) cartilage. This is simply not true, and although several studies have disproved this, the concept is still everywhere and even clinicians still spread this false information.


Not a single study has provided evidence for this hypothesis. Here are three studies that disprove this hypothesis:


Study 1: Eisinger et al., 2019


In this study, 16 people with pectus excavatum were compared to 16 age- and gender-matched controls (people without pectus excavatum). The authors found that in ribs 4 through 8, people with pectus excavatum had shorter cartilage (NOT longer) relative to bone length.


Study 2: Nakaoka et al., 2010


In this study, 20 people with prepubertal pectus excavatum were compared to 24 similarly aged healthy controls without pectus excavatum. They looked at only the 5th and 6th costal cartilages and ribs, but they found a similar result as above. That is, people with pectus excavatum do not have larger costal cartilage:bone ratios.