ABSTRACT
Current concepts of gout and calcium pyrophosphate dihydrate (CPPD)
deposition disease began with the microscopic identification of crystals in
synovial fluid by Hollander and McCarty in 1961-1962 (1), and microscopic
examination continues to be the principal method for crystal identification. Gout
in fact is defined by the presence of monosodium urate (MSU) crystals. CPPD
crystals can be seen in a variety of settings, may be a result of osteoarthritis or
other joint diseases, and do not as clearly define a disease. Other crystals have
now also been identified in joint fluids. These have a variety of implications.
