| Classification | Description | Notes |
| Type 1 | AC Joint strain | Normal radiograph |
| Type 2 | AC disrupted, CC strain | Mild vertical separation (normal AC interval 5-8 mm) |
| Type 3 | AC and CC disrupted | CC distance 25-100% of contralateral side |
| Type 4 | Distal clavicle positioned posterior to acromion | |
| Type 5 | Subcutaneous distal clavicle | CC distance >100% contralateral side |
| Type 6 | Distal clavicle positioned inferior to coracoid | Rare: Deep to conjoined tendon (coracobracialis, short head biceps) |
Reference:
Gorbaty, J. D., et al. (2017). “Classifications in Brief: Rockwood Classification of Acromioclavicular Joint Separations.” Clinical Orthopaedics and Related Research® 475(1): 283-287.
Rockwood CA Jr. Fractures and dislocations of the shoulder. In: Rockwood CA Jr, Green DP, eds. Fractures in Adults. Philadelphia, PA: Lippincott; 1984:860–910.