Ultrasound Case of Interest

David Pigott, MD, RDMS, FACEP
Co-Director UAB Emergency Ultrasound

This patient is a 40-year-old female with a history of uncontrolled DM and IV heroin use who presents with 4 weeks of worsening redness, swelling and pain over her R clavicle. She reports her sugars have been “too high to read.” She had a recent I&D of an abscess on her R wrist but denies injecting heroin into the affected area on her chest wall. Labs were remarkable for a WBC 16.9K and glucose >800 without an anion gap acidosis. Broad-spectrum antibiotics and an insulin infusion were started, along with IV fluid resuscitation.

Point-of-care US (POCUS) was performed of the affected area:

POCUS findings are notable for a subcutaneous abscess just overlying the proximal clavicle and sternoclavicular joint. Fluid from sternoclavicular joint can be seen extending into adjacent tissues.

CT Chest with contrast showed evidence of septic arthritis of the R sternoclavicular joint with subcutaneous and intrathoracic extension and osteomyelitis:

After initial evaluation and resuscitation, the patient was admitted to the Hospitalist service with Thoracic Surgery consultation.

The patient was subsequently taken to the OR where the R sternoclavicular joint and proximal clavicle were resected, the area debrided and extensively irrigated and covered with a wound vac.

Blood and tissue cultures were positive for MRSA. The patient underwent TTE which was negative for vegetations and was continued on IV vancomycin. She ultimately demanded that the wound vac be removed and left AMA 5 days following admission.

Sternoclavicular joint septic arthritis is a serious, rare complication of IV drug use, accounting for 7-9% of patients with septic arthritis. Delayed diagnosis, extra-articular infection and an immunocompromised host are also seen with this condition. A recent case report and review by Drs. Max Thompson and Dr. Kevin Barlotta is a great resource for more info on this disease:

Thompson MA, Barlotta KS. Septic Arthritis of the Sternoclavicular Joint. J Emerg Med. 2018 Jul;55(1):128-129.

© Copyright permission has been obtained from the UAB Department of Emergency Medicine Division of Ultrasound, Dr. David C. Pigott MD Co-Director of UAB EM Emergency Ultrasound