Alun Yewlett, Paul M.C. Dearden, Nicholas A. Ferran, Richard O. Evans & Rohit Kulkarni
Shoulder & Elbow 2012 4, pp 81-86
This is a very informative paper which discusses in detail AC joint anatomy, biomechanics, mechanisms and classification of injury.
Both conservative and surgical management are discussed.
You can access the full paper here.