Figure 1. Bone turnover in AS patients with ≥1 complete bridge (n = 52), ≥1 non-bridging syndesmophyte (n = 49), and without syndesmophytes (n = 50).

A) bone resorption marker sCTX, B) bone formation marker PINP, C) bone formation marker BALP. Box-and-whisker plots (Tukey): boxes indicate medians with interquartile ranges;+indicate means; whiskers indicate 1.5 times the interquartile distances; · indicate outliers.