There is more than one accepted classification for clavicle fractures. how it brakes? Most clavicle fractures are caused by a fall or other direct trauma to the shoulder, usually with the clavicle bending and breaking over the fulcrum of the first rib. Falls on an outstretched hand, although commonly cited, account for a smaller percentage of clavicle fractures. 1. Craig's classification For Clavicle fracture: Group I- fracture of the middle one third (most clavicular fractures are the group I fractures; Group II -fracture of the lateral or distal one third Type I -minimally displaced Type II -displaced secondary to a fracture medial to the coracoclavicular ligament complex Type III -fracture of the articular surface Type IV -ligaments intact to the periosteum, with a displacement of the proximal fragment Type V -comminuted Group III-fracture of the medial one third Type I -minimally displaced Type II -displaced ...