Abstract
We report an 83-year-old female patient who developed pyogenic arthritis of both knee joints almost synchronously. She initially complained of right knee pain and became unable to walk. Pus was drained by arthrocentesis, and Streptococcus agalactiae was detected. MRI scan showed no evidence of osteomyelitis. Arthroscopic debridement and closed suction-irrigation were performed, and an antimicrobial agent was administered. On the same day the patient complained of left knee pain. Similarly, pus was drained by arthrocentesis and the same bacterium was detected. We treated this episode in the same way, and CT scan demonstrated no antecedent infection.
There are very few reports of pyogenic arthritis developing at almost at the same time in both knee joints. With regard to the pathogenetic mechanism in this case, we consider that bilateral infection arose hematogenously from an asymptomatic antecedent infection resulting from the process of healing of a patellar fracture and resulting weakened resistance.
