Fig. 2From: 3D analysis of the distal ulna with regard to the design of a new ulnar head prosthesisThe cylinder was fitted into the ulnar trochlea. The coordinate system was aligned with the green arrow (y-axis) overlaying the humeral cylinder axis and is perpendicular to the ulnar axis. The blue arrow (z-axis) was set in the direction of the ulna, although its alignment does not have an influence on the here presented measurementsBack to article page