Acromioclavicular Joint Injuries: Evidence-based Treatment.

Injuries to the acromioclavicular (AC) joint are common in the athletic patient population. Most AC joint injuries occur in young males, typically from a direct fall onto the superior aspect of the shoulder when the arm is adducted. Numerous publications describing joint anatomy and biomechanics, surgical techniques for reconstruction, and rehabilitation protocols are available to guide treatment strategies for injuries to the AC joint. Treatment is typically nonsurgical for type I and II injuries and surgical for type IV and VI injuries. Controversy surrounds the indications for nonsurgical versus surgical treatment of type III and V injuries. Multiple surgical techniques have been described, including coracoclavicular (CC) screw fixation, coracoacromial ligament transfer, and numerous methods of CC ligament reconstruction. Anatomic CC ligament reconstruction can be performed either open or arthroscopically, with and without graft augmentation. This article will discuss clinically relevant anatomy and biomechanical properties of the AC joint and will review decision-making principles and treatment options for common AC joint injuries. An updated summary of clinical outcomes after AC joint treatment will also be presented.