[Bone mineral density and fracture risk in patients with ankylosing spondylitis].

Ankylosing spondylitis (AS) is an inflammatory disease primarily affecting the spine. Bone mineral density (BMD) is reduced in AS, particularly in male patients. Syndesmophyte formation may cause falsely increased BMD of the spine. The risk of spinal compression fractures may be 7-fold increased compared with healthy individuals. An increased risk of peripheral fractures has not been described. Structural spinal changes in advanced AS predispose to unstable vertebral fractures. Antiresorptive treatment is recommended for osteoporotic patients with AS, but the effect on BMD has never been studied in these patients.