Fig. 3.

Technique proposed by Renaud et al. Two main lines are placed for measurement: an acromial line that represents the superior cortex of the acromion, and a tangent line to the centre of the prosthetic epiphysis or to the centre of rotation of the humeral head perpendicular to the first line. The two latter lines represent the acromioepiphyseal distance and are compared to provide a ratio of lengthening. From [30], with permission