A 72-year-old man presented to our clinic with a 1-year history of pain and swelling of the right knee. He had been having intermittent pain in both knees for 15 years. Medication for mild degenerative arthritis had been recommended, but the patient refused treatment. A year before he presented to our clinic, he visited another clinic due to the aggravation of pain and swelling of the right knee and was diagnosed with severe degenerative arthritis by radiologic and physical exam, and a decision was made to perform total knee arthroplasty. During the operation, severe inflammation and an abscess were found inside the knee joint; therefore, bacterial culture was obtained and arthroplasty was not performed. After the operation, he was diagnosed by culture with unknown-originated joint infection and transferred to our clinic. The medical history was negative for rheumatoid disease, cancer, renal disease, and HIV. He was a nonsmoker and nondrinker and did not take any steroids or illegal drugs. On physical examination, the patient had signs of infection, including swelling and localized warmth, of right knee. Knee radiographs revealed multiple patched subchondral lesions of the distal femur and proximal tibia, severe joint space narrowing, and definite osteophytes (Figure 1(a)). These findings were suggestive of a degenerative knee joint (K-L grade IV).
The laboratory results were as follows: white blood cell (WBC), 11,200/mm3 (4-10 x 103/mm3); erythrocyte sedimentation rate (ESR), 97 mm/hr (0-15 mm/hr); C-reactive protein (CRP), 19.2 mg/dL (0-5 mg/dL). Tests for anti-nuclear antibody (ANA), rheumatoid factor (RF), and HLA B27 were all negative. The joint fluid cytology findings were as follows: appearance, cloudy and reddish; WBC, 17,200/mm3 (0-200/mm3) with 85% neutrophils and 10% lymphocytes. The Gram stain and acid-fast bacteria (AFB) stain showed no bacteria or tuberculosis. Candida guilliermondii was cultured in the joint fluid on hospital day 7 and was confirmed on hospital day 8. Amphotericin B (0.7 mg/kg/day) was given intravenously. Two weeks later, CRP had normalized. After 4 weeks, the amphotericin B was discontinued and oral fluconazole (400 mg/day) was prescribed for 6 months. The last culture of joint fluid was negative for C. guilliermondii, and the patient had no complaints of pain or swelling. The ESR/CRP was continuously maintained at normal state. After the inflammation had resolved, the patient had pain on the medial side of the knee joint with ambulation, and rechecking knee radiographs revealed aggravation of the patient's intra-articular deformity due to the candidal infection (Figure 1(b)). After 4 months, primary total knee replacement with a Duracon prosthesis (Howmedica, Rutherford, NJ, USA) was performed (Figure 2). The wound was daily dressed, and intravenous amphotericin was injected; however, redness and swelling were observed at the proximal operative site 1 week postoperatively (Figure 3).
 The patient was diagnosed with a superficial infection, and wound debridement and closure were performed. So far, after discharge, there were no abnormal findings or signs of infection.