Measurement and Treatment of Radiographic Progression in Ankylosing Spondylitis: Lessons Learned from Observational Studies and Clinical Trials

PURPOSE OF REVIEW One of the major goals of treatment of ankylosing spondylitis (AS) is to prevent or slow the development of spinal new bone formation. Recent observational studies are compared to results from clinical trials for the effects of tumor necrosis factor-alpha inhibitors (TNFi) and nonsteroidal anti-inflammatory drugs (NSAIDs) on radiographic measures of spinal damage.