Calcium pyrophosphate deposition disease (CPPD) is a rheumatologic disorder with varied clinical manifestations due to precipitation of
calcium pyrophosphate dihydrate crystals in the connective tissues. It is more commonly known by alternative names that specify certain clinical or radiographic findings, although neither is synonymous with CPPD. Pseudogout refers to the clinically evident acute
synovitis with red, tender, and swollen joints that may resemble
gouty arthritis (a similar condition with joint deposition of monosodium
urate crystals). Chondrocalcinosis, on the other hand, refers to the radiographic evidence of calcification in hyaline and/or fibrocartilage. Pyrophosphate arthropathy is a term that may refer to either of the above, but is uncommonly used.
See more at Wikipedia.org...