Streptococcus anginosus-constellatus infection of the sternoclavicular joint

We describe the first reported instance of sternoclavicular pyarthrosis caused by Streptococcus anginosus-constellatus. Infections caused by this organism are unusual in a nonimmunocompromised host. Common conditions predisposing to sternoclavicular joint infection were not present. A possible mechanism for the infection is offered.