Symptoms and signs of septic arthritis are an important medical emergency, with high morbidity and mortality. We review the changing epidemiology of septic arthritis of native joints in adults, encompassing the increasing frequency of the disorder and its evolving antibiotic resistance. We discuss various risk factors for development of septic arthritis and examine host factors (tumour necrosis factor a, interleukins 1 and 10) and bacterial proteins, toxins, and enzymes reported to be important...