Treatment of septic arthritis

Raheem Kherani and Kam Shojania recently provided a comprehensive overview of septic arthritis; however, I have some concerns about the antimicrobial therapies outlined in their article.¹ The authors recommend that gram- positive cocci identified in Gram's staining of synovial fluid should be treated with cefazolin if the infection was acquired in the community. This treatment recommendation does not consider the emergence of community-acquired methicillin-resistant Staphylococcus aureus in Canada.² When one is treating an infection that leads to joint destruction or sepsis, it is prudent to include vancomycin as a first-line agent until the antibiotic susceptibility of the organism is known.³

My second concern is the authors' recommendation that cefazolin and gentamicin should be used to treat cases in which Gram's staining does not show bacteria. Most treatment recommendations for this scenario include a third-generation cephalosporin and vancomycin for empiric coverage of the most common bacterial pathogens. Neisseria gonorrhoeae would also be covered by this broader regimen; it is a common cause of septic arthritis in patients at risk for sexually transmitted infections. With the rising incidence of gonorrhea in Canada⁴ and the frequency of a negative result of Gram's staining with gonococcal arthritis, this organism should at least be considered when treating septic arthritis.