Staphylococcus lugdunensis Septic Arthritis of a Native Knee A Case Report.

A 67-year-old man presented to orthopaedic care with a painful knee. Workup was consistent with septic arthritis of a native knee, and the patient underwent operative treatment. Cultures from the operating room were speciated to Staphylococcus lugdunensis. To the investigators' knowledge, this is the first reported S. lugdunensis infection in a peripheral joint in the absence of an orthopaedic prosthesis. Although traditionally associated with infectious endocarditis, S. lugdunensis has been identified as a causative agent in many organ systems, including orthopaedic infections. This case report emphasizes the importance of familiarity with this emerging pathogen in the treatment of a septic joint.