Topic overview

Start with the big picture

The lesson follows septic arthritis from pathogenesis and risk factors through microbiology, diagnosis, treatment, and follow-up. It highlights hematogenous spread as the dominant route and explains why rapid cartilage destruction makes urgent care essential. Risk factors include prosthetic joints, rheumatoid arthritis, diabetes, intravenous drug use, recent surgery, and older age. Pathogens vary by setting, with Staphylococcus aureus prominent and other organisms associated with particular patient groups. Diagnosis centers on prompt joint aspiration for cell count, Gram stain, and culture, alongside consideration of blood cultures. Initial management connects empiric antibiotics with culture results, while drainage and debridement provide essential source control. The lesson also addresses treatment duration, monitoring, complications, prevention, and practical key points.