Proximal fractures of the humerus only account for about 5% of all fractures but account for 45% of all humeral fractures.
We should be familar with the Neer Classication System for Humeral fractures, which can also be seen at http://health-7.com/Handbook%20of%20Fractures/15%20-%20Proximal%20Humerus%20Fractures
The classification system classifies fractures based on
1-part
2-part
3-part
4-part
The bony segments that make up the parts are
Greater Tuberosity (GT)
Lesser Tuberosity (LT)
Humeral Head
Humeral Surgical Neck (SN)
A part is defined as displaced if >1 cm of fracture displacement or >45 degrees of angulation.
The greater the number of parts the more likely the patient will require surgery or have increased complications.
3 and 4 part fractures are often fixed surgical due to the increased risk of vascualr compromise to the humeral head.