Pseudogout after total knee arthroplasty.

We report a case of a patient who presented with signs and symptoms of acute septic arthritis of the knee 9 years after total knee arthroplasty. Thick white purulent fluid was aspirated from the knee. Microscopy of the fluid demonstrated calcium pyrophosphate dihydrate crystals, and no organisms were cultured. The patient made a rapid recovery after the single aspiration, rest, and nonsteroidal antiinflammatory drugs alone. Eight years after this episode, the patient remains asymptomatic. To the best of our knowledge, no case of calcium pyrophosphate dihydrate arthropathy after total knee arthroplasty has been reported previously.