Sternoclavicular joint septic arthritis: an interesting lesson in clinical anatomy

An otherwise healthy 45-year-old man presented to our emergency department holding his left arm in abduction and external rotation. He reported pain in his left shoulder and chest for the preceding 10 days that had become much worse over the last 48 h and was eased only by holding his arm in this position. The CT of the chest revealed soft tissue swelling around the left sternoclavicular joint consistent with sternoclavicular joint septic arthritis with significant inflammatory involvement of the medial component of the left pectoralis major muscle. The patient was taken to theatre for washout of the left sternoclavicular joint and is currently recovering well at home on intravenous antibiotics.