Surgical Neck Fractures of the Humerus Wheeless

Description: most common fracture of proximal humerus;
- frx is extracapsular, usually has an adequate blood supply and relatively low incidence of AVN;
- in contrast, anatomic neck frx has much higher incidence of AVN;
- upper fragment is usually abducted & externally rotated by muscles inserting onto greater tubercle, while lower fragment is adducted & internally rotated by internal rotators;
- stable vs unstable fractures:
- surgical neck fractures should be classified as either stable or unstable;
- unstable fractures may result from either low or high velocity forces;
- compression fractures tend to be stable,
- shear injuries tend to be unstable;
- periosteal tissue disruption leads to increased fracture instability;
- unstable fractures will display gross motion between shaft & head fragments
Wheeless Textbook of Orthopaedics