Calcium pyrophosphate deposition disease or CPPD. Root Cause of Disease Pseudogout it is the one type of Knee Pain. Pseudogout often mistaken for gout, pseudogout is caused by calcium-containing crystals that develop in the joint fluid. Knees are the most common joint affected by pseudogout. Pseudogout (SOO-doe-gout) is a form of arthritis characterized by sudden,…