Pseudogout is a form of arthritis common in the knee, characterized by sudden episodes of joint pain and swelling that can last for days or weeks. Also called calcium pyrophosphate deposition disease (CPPD), pseudogout is similar to gout in that both conditions involve the build up of crystals in the fluids that lubricate joints.
Pseudogout occurs when calcium pyrophosphate dihydrate crystals move from the protective cartilage around joints into the synovial fluid and cause inflammation. Although researchers are not sure why these crystals form, it is believed to be associated with aging. No treatment can remove the crystals from the joints, but drug therapy has shown to be effective in controlling pain and swelling.