Figure 1

Binary (LEGO) description system of the Hertel classification of proximal humerus fractures. The 12 basic fracture patterns result after combining the 5 basic fracture planes. Basic fracture planes lie between the greater tuberosity and the head, the greater tuberosity and the shaft, the lesser tuberosity and the head, the lesser tuberosity and the shaft, and the lesser tuberosity and the greater tuberosity. There are 6 possible fractures dividing the humerus into two fragments, 5 possible fractures dividing the humerus into three fragments, and a single fracture dividing the humerus into four fragments Categories eligible for enrolment into the current trial are indicated in red boxes.

Reprinted from J Shoulder Elbow Surg, 13, Hertel R, Hempfing A, Stiehler M, Leunig M: Predictors of humeral head ischemia after intracapsular fracture of the proximal humerus, pp 427-433, with permission from Elsevier.