Vertebral Bone Mineral Density, Vertebral Strength, and Syndesmophyte Growth in Ankylosing Spondylitis: The Importance of Bridging.

Associations between syndesmophytes and vertebral density and strength in AS differ between bridged and nonbridged vertebrae. Among nonbridged vertebrae, low tBMD and strength are associated with syndesmophyte growth. Bridging is associated with large subsequent losses in tBMD, possibly due to mechanical offloading.