Classification of acromioclavicular joint injury

  • Type I: sprain of acromioclavicular ligaments, functionally intact. Intact coracoclavicular ligament. Normal radiograph. Tender, painful joint
  • Type II: disrupted acromioclavicular ligaments. Sprained coracoclavicular ligament which is intact. Wide acromioclavicular joint, acromioclavicular subluxation
  • Type III: acromioclavicular and coracoclavicular ligament disrupted. Superior displacement of clavicle. Acromioclavicular dislocation
  • Type IV: acromioclavicular and coracoclavicular ligament disruption. Posterior displacement of clavicle into trapezius. Seen in axillary view
  • Type V: more sever version of type III. Marked superior displacement of clavicle. Coracoclavicular distance 2-3 times the normal. Distal clavicle subcutaneous. Torn deltoid and trapezius. Marked drooped shoulder
  • Type VI: inferior dislocation of distal clavicle. Shoulder appears flat. Can be subcoracoid or subacromial.