Acromioclavicular joint sprains are classified based on x-ray findings: Type I: No joint disruption Type II: Subluxation with some overlap of the clavicle and acromion Type III: Complete joint dislocation, usually because the coracoclavicular ligament is torn Type IV: Posterior displacement of the distal clavicle Type V: Superior displacement of the distal clavicle Type VI: Inferior displacement of the distal clavicle Types IV, V, and VI are variants of type III.