Acromioclavicular septic arthritis and sternoclavicular septic arthritis with contiguous pyomyositis.

Acromioclavicular (AC) and sternoclavicular (SC) septic arthritis with contiguous pyomyositis are rare, especially in immunocompetent individuals. We report a case of septic AC joint with pyomyositis of the deltoid and supraspinatus muscles and a separate case with septic SC joint with pyomysitis of the sternocleidomastoid muscle. Both patients had similar presentations of infections with Staphylococcus aureus and were successfully treated with surgical incision and drainage followed by prolonged antibiotic therapy.