<unk><unk><unk>  (CPPD) crystal<unk><unk> , also known as pseudogout and<unk>  arthropathy, is a rheumatologic<unk>  which is thought to be secondary to abnormal accumulation of<unk><unk><unk>  crystals within joint soft tissues. The knee joint is most commonly affected.
Calcium pyrophosphate dihydrate crystal deposition disease
Gout
Ectopic calcification
Metastatic calcification
AA amyloidosis
Secondary systemic amyloidosis
Crystal arthropathy
Cartilage tumor