Index for Measurement of Pectus Excavatum

Abstract

The severity of pectus excavatum is quantified by the use if index measurements. The clinical standard has historically been the Haller index (HI), which was initially described in 1987. This metric was defined as the ratio of the distance between the anterior spine and posterior sternum to the widest transverse diameter of the chest. In general, the deep point at the bottom of the sternum is chosen as the location to measure the denominator. In other words, the number means the number times the chest is wider than it is deep at the deepest point of the sternal depression. Recent evidence demonstrates that the impact of width in the equation results in tremendous overlap in HI between normal controls and pectus patients. The more recent pectus correction index firmly separates normal patients from pectus patients by providing an accurate assessment of sternal depth relative to the anterior chest wall. The equation utilizes the minimum distance between posterior sternum and anterior spine and the maximum distance between anterior spine most anterior portion of the chest. The difference between the 2 is divided by the latter (× 100) to give the percentage of chest depth the defect represents.