A1.1 fractures are undisplaced fractures of the greater tuberosity. enlarge

Although these fractures are undisplaced fractures of the greater tuberosity, displacement may occur during the first week or two after injury.

The greater tuberosity fragment tends to be displaced superiorly and posteriorly due to the pull of the rotator cuff (supraspinatus and infraspinatus tendon). If the greater tuberosity heals with displacement, it may impinge upon the coracoacromial arch, limiting motion, and producing pain.