<prompt> The pathogonomic finding in pseudogout is -CPPD crystals under microscopePolyarthritis with urinary sedimentJuxta - articular osteopeniaBone spurs  <response>: Ans. is a i.e., CPPD crystals under microscope Pseudogouto It is one of the forms of Calcium pyrophosphate dihydrate CPPD arthropathyo Pseudogout commonly involves the larger joints. Knee joint is most commonly involved: other sites are wrist, elbow, shoulder, ankle. Involvement of small joints is uncommon.o Age group is 60 yrs.o In CPPD arthropathy, CPPD deposition occurs in articular tissues. It can present in any of the following three forms-Asympatomatic chondrocalcinosisAcute synovitis - PseudogoutChronic pyrophosphate arthropathyo The radiologic hallmark of CPPD is chondrocalcinosis. Chondrocalcinosis is seen as punctate andor linear radiodense deposits in fibrocartilaginous joint menisci or articular hyaline cartilage,o Definitive diagnosis is made by synovialfluid polarised light microscopy which shows weakly positive, birefringent, rhomboid crystals of CPPD. o In acute synovitis form, leucocytosis thousands to 1 lac cells 1 is seen in synovial fluid examination,o It may be associated with certain underlying disease such as -Primary hyperparathyroidismHemochromatosisHypomagnesemiaHypophosphatasiaHypothyroidism 