A1.3 fractures are glenohumeral dislocations with associated tuberosity fractures. enlarge

Almost all of these fractures involve the greater tuberosity.

Reduction of the glenohumeral joint should be performed as an emergency procedure. Once the glenohumeral joint is reduced, the tuberosity fracture is treated as appropriate.

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 (5 mm or more), it may impinge upon the coracoacromial arch, limiting motion, and producing pain. In this position, it provides a shorter lever arm for the supra- and infraspinatus tendons, and thus weakens them.

The biceps tendon may be incarcerated in the fracture.