Plain radiographs as an outcome measure in ankylosing spondylitis

Radiographic evidence of sacroiliitis is a prerequisite for classification according to the (modified) New York criteria. Structural damage is also an important endpoint in the assessment of ankylosing spondylitis (AS). Howev er, little research has been done on the development, validation, and appli cation of scoring methods for radiographic changes in AS. Methodological is sues that can be addressed concerning radiographic scoring methods are disc ussed in detail. A short introduction to the available scoring methods is p resented.