Musculoskeletal ImagingRheumatic fever
a pathologic condition characterized clinically by fever, carditis and polyarthritis, often occurring after an episode of group A beta-haemolytic streptococcal infection. Typically joint involvement occurs as polyarthritis and
Jaccouds arthropathy.
Articular findings vary in severity from arthralgia to arthritis. Joint inflammation may last for several days to a week, later diminishing and eventually disappearing. On radiographs, soft tissue swelling without evidence of cartilage or bone destruction may be observed.
Jaccoud's arthropathy, which is also known as deforming nonerosive arthropathy, has typical radiographic abnormalities. This entity appears to result from capsular inflammation and fibrosis. It is not diagnostic of rheumatic fever but may also occur in other pathologic conditions. Changes in the hand resemble those in systemic lupus erythematosus and other collagen diseases. Symptomless and reversible joint deformities appear, such as ulnar deviation and flexion deformities at the metacarpophalangeal joints, which may be combined with hyperextension at interphalangeal joints. In the foot, fibular deviation and subluxation at metatarsophalangeal joints can be observed.
On radiographs, joint space narrowing and bone erosions are not evident, but hook erosions on the radial and palmar aspects of the metacarpal heads can appear in Jaccoud's arthropathy. Superficially these lesions resemble the marginal erosions of rheumatoid arthritis. The hook erosions may be produced by pressure erosion beneath the distorted capsule in the deformed joints.
DR