Proximal Humerus Fracture

A proximal humerus fracture is a break of the upper humerus, most often a low-energy fragility fracture in an older adult after a fall.

Incidence peaks in older women with osteoporosis; younger patients usually have a high-energy mechanism such as sport, a road traffic collision or a fall from height. About half are minimally displaced, and most are managed without surgery. The key questions are whether the fracture is displaced, whether the humeral head blood supply is at risk, whether there is a fracture-dislocation, and whether red flags are present.

The anatomical neck sits above the tuberosities at the edge of the articular surface; the surgical neck sits below them and is the most common fracture site. Neer described 4 segments: the humeral head, the greater tuberosity (supraspinatus, infraspinatus, teres minor), the lesser tuberosity (subscapularis) and the shaft.

Both circumflex humeral arteries supply the head. Traditional teaching emphasised the anterior circumflex humeral artery, but a cadaver study (Hettrich, 2010) found the posterior circumflex humeral artery provides about 64% of the supply. In younger adults with high-energy injuries, look for cervical, chest and other upper limb injuries.