Staphylococcal septic synovitis of the sternoclavicular joint with retrosternal extension.

Bacterial arthritis of the sternoclavicular joint is an uncommon disorder caused by a variety of microorganisms. Both Gram-positive and Gram-negative bacteria have been identified as etiologies of an acute suppurative arthritis, whereas a few other bacteria such as mycobacteria and treponemes have been incriminated in chronic disease of the sternoclavicular joint. We recently treated a patient with staphylococcal synovitis of the sternoclavicular joint, which is the 24th recorded in the literature. His illness was complicated by a retrosternal abscess, soft tissue abscess of the chest, septic bursitis, and lumbosacral discitis. He recovered after 6 weeks of nafcillin therapy without any residual infection. Six previous patients with extension into the substernal space and mediastinum have been described. Staphylococcal infection of the sternoclavicular joint, although usually confined to the joint, can be associated with sepsis and metastatic abscess formation as well as substernal extension even in immunocompetent individuals.