Table 1. Rockwood Classification of Acromioclavicular Joint Injuries.

Injury Type	Acromioclavicular Ligament	Coracoclavicular Ligament	Trapezoid and Deltoid Muscles
I	Partial tear	No tear	No tear
II	Complete tear	Partial tear	No tear
III	Complete tear	Complete tear	No tear
IV	Complete tear	Complete tear	Distal end of the clavicle is displaced posteriorly into or through the trapezius muscle
V	Complete tear	Complete tear	Detachment from distal part of clavicle
VI	Complete tear	Complete tear	Inferior displacement of the clavicle beneath the coracoid process