Radiographic imaging: the 'gold standard' for assessment of disease progression in rheumatoid arthritis.

Rheumatoid arthritis (RA) is characterized by a chronic inflammation of the joints, which leads to the destruction of articular cartilage and bone. The degree of joint damage assessed by radiographic imaging represents a key outcome in RA. There are several methods for scoring the joint damage associated with RA. The most widely used are the Sharp and Larsen systems, as well as more recent modifications of each method. Radiographic imaging has several advantages compared with other outcome measures in RA, specifically: X-rays reflect the history of joint pathology, provide a permanent record for serial evaluation, and can be randomized and blinded for objective scoring. Several modifications of these methods have been proposed and employed in the investigation of disease progression. A review of the radiographic progression of RA is presented, as well as a simplified scoring system useful for the evaluation of joint damage in RA in a clinical setting.