Acute septic arthritis of the acromioclavicular joint caused by Staphylococcus aureus with marked soft tissue collection towards posterior medial aspect of the AC joint: A rare clinical presentation.

Primary septic arthritis of the Acromioclavicular joint is an unusual disorder and is seldom seen even in an immunocompromised person. We report a case of primary septic arthritis of the acromioclavicular (A-C) joint caused by Staphylococcus aureus. The patient was admitted with pain in the left shoulder, restricted movements and fever.