Pseudogout Mimicking Infection Following Total Knee Arthroplasty: A Report of Two Cases.

Abstract

One of the most serious postoperative complications following total knee arthroplasty is periprosthetic infection, with a reported rate of 1% to 2%1. Early diagnosis of the infection is critical for successful treatment, but diagnosis can be difficult. An acute pseudogout attack, for instance, should be included in the differential diagnosis of septic arthritis because the two conditions can have similar presentations, including joint pain, swelling, fever, and elevations in serum inflammatory marker levels. Several pseudogout cases mimicking infection after total knee arthroplasty have been reported, but most of these developed years after the surgery2-5. We report two cases of pseudogout mimicking infection that arose within two weeks after total knee arthroplasty. The patients were informed that data concerning their cases would be submitted for publication, and they provided consent. Case 1. A sixty-four-year-old woman with a history of hypertension underwent a primary right total knee arthroplasty for osteoarthritis (OA). Two days after the surgery, she began rehabilitation therapy; thirteen days after the surgery, she developed a fever of 38.4°C. The right knee was swollen and warm to the touch, but the surgical wound was free of drainage and was healing well. She had no pain in the right knee and was not taking nonsteroidal anti-inflammatory drugs (NSAIDs). Both the C-reactive protein (CRP) level (22.5 mg/L; normal: <3 mg/L) and the erythrocyte sedimentation rate (ESR) (29 mm/h; normal: <10 mm/h) were elevated. The total white blood-cell count and neutrophil count were 6.4 × 108/L and 4.9 × 108/L, respectively. She walked with a cane and had a knee range of motion …