Fig. 2

Definition of point, line, and plane of proximal humerus. a Line AB = humeral shaft axis (HSA) in perspective mode. b C = most superior point of articular surface; D = most inferior point of articular surface; E = concave point of articular surface; F = furthest vertical distance point on articular surface to plane 1; G = most superior point of humeral head; H = most superior point on greater tuberosity; plane 1 = anatomical neck plane; plane 2 = the plane that was via point G and parallel to the transverse axis of humeral shaft. c I and J = intersection of plane 1 and plane 3 on the articular surface; plane 3 = axial plane that was the vertical plane through the midpoint of line CD