Septic arthritis of the acromioclavicular joint: an uncommon location.

Septic pyogenic arthritis of the acromioclavicular joint is a rare entity that occurs in immunosuppressed patients or those with discontinuity of defense barriers. There are only 15 cases described in the literature. The diagnosis is based on clinical features and the isolation of a microorganism in synovial fluid or blood cultures. The evidence of arthritis by imaging (MRI, ultrasound or scintigraphy) may be useful. Antibiotic treatment is the same as in septic arthritis in other locations. Staphylococcus aureus is the microorganism most frequently isolated. Our objective was to describe the clinical features, treatment and outcome of patients diagnosed with septic arthritis of the acromioclavicular joint at a Rheumatology Department. We developed a study with a retrospective design (1989-2012). The medical records of patients with septic arthritis were reviewed (101 patients). Those involving the acromioclavicular joint were selected (6 patients; 6%).