This study was to describe the characteristics of syndesmophytes in different inflammatory and non-inflammatory diseases aiming to reflect the aortic-vertebrae interaction.
We conducted a cross-sectional study including four group of patients, ankylosing spondylitis (AS, n=52), Takayasu's arteritis (TKA, n=31), diffuse idiopathic skeletal hyperostosis (DISH, n=30), coronary artery disease (CAD, n=100), and also age-matched healthy controls (HC, n=143). All subjects underwent a chest CT and images of the upper and lower border of seven adjacent thoracic vertebrae (T5 to T12) were captured. An ‘aorta ipsilateral ratio’ (AIR) of the syndesmophyte was calculated as the area crossed the midline toward aorta side divided by the total syndesmophyte area.
The frequency of subjects with syndesmophyte and syndesmophyte counts increased with age across the board. Frequencies of syndesmophyte in AS and TKA were much higher than age-matched HCs. The AIRs were significantly elevated in AS, TKA and CAD compared with DISH or age-matched HCs. In addition, the AIR of patients with higher CRP levels (>8mg/L) were greater than that of those with lower levels, both among AS and CAD patients.
Our findings indicate that, in an inflammatory niche, regardless the origin or the grade of the inflammation, syndesmophyte formation will be facilitated and screwed toward aorta. There is a possible mechanistic connection between large vessel and new bone formation in the context of inflammation.