Septic arthritis of the acromioclavicular joint.

A patient with isolated pyogenous arthritis of the acromioclavicular joint (A-C joint) caused by Streptococcus viridans is described. The patient had no underlying disease. Minor trauma preceded shortly the development of the septic process. The patient was treated successfully with surgical drainage and antibiotics. To our knowledge this is the first case report of septic arthritis of the A-C joint caused by Streptococcus viridans. The A-C joint is rarely involved in septic processes. Even conditions such as intravenous drug abuse [3, 6] and renal dialysis [4, 7] which tend to infect unusual joints [5] have only rarely been described in association with A-C septic arthritis.