Acromioclavicular (AC) Joint Septic Arthritis on POCUS IVDU with severe left shoulder pain. Can fully range but has significant tenderness. Temp-102.9. Tender on top of shoulder with redness. No murmur. no stigmata of endocarditis. Diagnosis? Scan over AC joint showed effusion. WBC/CRP/ESR elevated. Arthrocentesis-64K WBC with no crystals. Culture MRSA. AC joint septic arthritis rare. Usually in immunosuppressed but can be seen in IVDU (same with sternoclavicular septic joint). AC joint septic arthritis can be confused with glenohumeral joint septic arthritis. This patient had no glenohumeral joint effusion. Dr. Robert Jones @RJonesSonoEM #Acromioclavicular #AC #Joint #Septic #Arthritis #Effusion #POCUS #clinical #ultrasound #MSK
