Northwestern University Feinberg School of Medicine

Orthopedic Teaching

Shoulder Case 8 Background

AC Separation


Background

Acromioclavicular (AC) separations are frequent shoulder injuries in emergency medicine. Most patients give a history of falling and striking the lateral shoulder while adducted, usually in athletics or a mechanical fall. There are two main complexes of ligaments involved, the AC ligaments and the coracoclavicular (CC) ligaments. The AC ligaments rupture first, then the CC ligaments.