31st January 2024

Septic arthritis

Septic arthritis is a potentially life-threatening condition. It should be suspected in anyone who is systemically unwell with or without fever and has an acutely hot, swollen, painful joint. The sepsis 6 guidelines should be followed, and local guidelines of antibiotic choice used. Once clinically suspected, septic arthritis should be investigated and treated urgently, as there is a ~10% mortality rate in septic arthritis. 

Treatment with intravenous antibiotics and fluids should commence within 1 hour of clinical suspicion. Culture sample should be taken in the same way as for treatment of sepsis; however, importantly, joint aspiration samples should be obtained using an antiseptic non-touch technique. If confirmed, discussion with the Orthopaedics team is often needed for consideration of joint washout. If there is a suspected joint prosthesis infection, discussion with the orthopaedic team is needed promptly, and joint aspiration should be performed by them. 

Joints are commonly infected with bacteria, but viral and fungal infections should be considered in the differential diagnoses as treatment will differ. Microbiology advice should be sought if there is doubt.

Delayed or poorly treated septic arthritis can result in reduced joint functioning and possibly joint loss, and therefore, long-term disability.