Staphylococcus lugdunensis: An emerging pathogen of surgical site infections after knee arthroscopy-related procedures

PURPOSE: We report our experience with 4 patients with septic arthritis after knee arthroscopic related procedures with Staphylococcus lugdunensis as the pathogen. METHODS: Between December, 2011 and September 2012, we identified 4 cases of knee arthroscopy-related procedures that were infected by S. lugdunensis postoperatively. The demographic, clinical, and laboratory data of these cases are described, as is the epidemiological investigation that followed this cluster of uncommon events. RESULTS: Three patients who underwent anterior cruciate reconstructions procedures and 1 patient who underwent an artificial meniscus implant procedure presented with fever or a painful red knee within 1 week of the index surgery. Their C-reactive protein and white blood cell levels were elevated. All 4 grew S. lugdunensis from the synovial fluid aspirate with different antibiograms and were treated with urgent debridement and lavage followed by a prolonged course of intravenous antibiotics. Two patients needed more than 1 debridement of the joint. All patients reacted favorably to this course of treatment. A comprehensive infection control unit investigation did not uncover the source of this outbreak and suggested that the probable cause was disinfected arthroscopic equipment. CONCLUSIONS: S. lugdunensis has the propensity to cause an aggressive infection after arthroscopic procedures. Treatment with arthroscopic debridement and prolonged intravenous antibiotics resolved the infections in all of our 4 cases. Stringent observation of arthroscopic equipment sterilization protocols is warranted to prevent the recurrences of these infections.