Correlation between Sternal Slope Angle and Primary Spontaneous Pneumothorax in Young Males, a Propensity Score Match Analysis

Abstract

It is generally accepted that primary spontaneous pneumothorax (PSP) is found mostly in tall, thin young males. However, the precise etiology of PSP is unclear. We compared some thoracic structural angles of PSPs and controls in young males to determine the predominant factor. CT data of 43 male PSPs (age 21.88 AE 5.30) and 30 controls (age 21.47 AE 5.47) were collected. The angle of thoracic vertebrae slope (∠α), sternal slope angle (∠β), and tracheal-sternal stem angle (∠γ) were measured in the sagittal position. Carina angle (∠δ) was measured in the coronal position. After a propensity score match (PSM) of age and smoking history, the angles were comparatively evaluated. There were significant differences in all four angles between two unmatched groups, while only in three (∠β, ∠γ, and ∠δ) after PSM was performed. The correlation between ∠β and PSP was most significant, and R 2 was 0.456. The prediction accuracy of ∠β was 81.3%, OR was 1.386, 95% confidence interval was (1.095-1.754). The sternal slope angles in PSPs are greater than controls indicate the sternal slope angle is associates with the development of PSP and it could be a thoracic structural index to predict the risk of PSP occurrence. Clin. Anat. 33:605-609, 2020.