Radiographic scoring methods in rheumatoid arthritis and psoriatic arthritis

Structural changes of bone and cartilage are the hallmarks of rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Radiography can help in making diagnosis and in differentiating PsA and RA from other articular diseases. Radiography is still considered the preferred imaging method to assess disease progression, reflecting cumulative damage over time. The presence of bone erosions in RA is as an indicator of irreversible articular damage. Radiographic features of PsA are characteristic and differ from those observed in RA, especially in the distribution of affected joints and in the presence of destructive changes and bone proliferation at the same time. Semiquantitative scoring methods are designed to measure the degree of radiographically detectable joint damage and of changes over time. Several radiographic scoring methods that had been developed originally for RA have been adopted for the use in PsA. This review discusses the use of conventional radiography for diagnosing and detecting early structural changes in RA and PsA and providing a historical overview of commonly used scoring methods.