Rapid Review: Septic Arthritis

Reviewed February 2024

Septic Arthritis

• Patient may present with fever, monoarticular pain with decreased ROM
• Labs from arthrocentesis: WBC > 50,000/µL with > 75% PMNs
• Diagnosis is made by arthrocentesis
• Most common cause overall: S. aureus
• Infants < 3 mo: Group B Streptococcus (Streptococcus agalactiae)
• N. gonorrhoeae is a common cause in young, sexually active individuals
• Tx: IV Abx, joint drainage, surgical washout

Sample Question:

A 23-year-old man with a history of intravenous heroin use presents to the emergency department with a painful left hip that is preventing him from walking. He denies injury. Physical exam reveals a swollen and erythematous left hip that is tender to palpation. His temperature is 102.2°F. What is the most likely causative pathogen?