Measurement of sternal curvature angle on patients with pectus excavatum

Pectus Excavatum (PE) comes in all shapes and sizes. It is not uncommon for PE to be asymmetric. That is, the part of the chest that is concave may not be perfectly centered in the chest. One way to measure the asymmetry of PE is to examine the sternal curvature angle (SCA). This value represents how much the sternum is twisting, so to speak. A normal value in individuals without PE is about 22 degrees. In this research article, the authors found that the average SCA for a total of 202 PE patients was about 40 degrees. Interestingly, there was no relationship between SCA and Haller index, an objective measure of severity. However, in this study, they used X-rays to measure the SCA, whereas it's normally done using a CT scan for a more accurate measure. The authors hope that measuring the SCA value for PE individuals will help motivate future studies asking what the underlying cause of PE is.