Crystal induced arthropathies
are disorders involving crystal deposition in the articular and peri articular
soft tissues with resultant inflammation. Gout and calcium pyrophosphate
dihydrate (CPPD) crystal deposition disease are the two most common types of
crystal- deposition arthritis. The diagnosis is
primarily based on clinical and laboratory findings,
especially synovial fluid analysis. Radiographs can further aid clinicians in
establishing the correct diagnosis.
Acute gout most
frequently involves the first metatarsophalangeal (MTP) joint at first
presentation. However, it has non-specific radiographic features. Chronic gout
has a characteristic radiographic appearance with tophus considered to be a
hallmark feature.
Tophi are seen as
focal eccentric soft tissue swelling of the affected joints or soft tissues
resulting in a "lumpy bumpy appearance" and cause well-defined
punched out juxta-articular erosions with sclerotic rims and overhanging edges
due to pressure on the adjoining bone
