Radiographic evaluation of arthritis: inflammatory conditions.

In the presence of joint space narrowing, it is important to differentiate inflammatory from degenerative conditions. Joint inflammation is characterized by bone erosions, osteopenia, soft-tissue swelling, and uniform joint space loss. Inflammation of a single joint should raise concern for infection. Multiple joint inflammation in a proximal distribution in the hands or feet without bone proliferation suggests rheumatoid arthritis. Multiple joint inflammation in a distal distribution in the hands or feet with bone proliferation suggests a seronegative spondyloarthropathy, such as psoriatic arthritis, reactive arthritis, or ankylosing spondylitis.