Fig. 2
From: Long-term results after non-operative and operative treatment of radial neck fractures in adults
Method to determine the dislocation of the radial head towards the radial shaft. First, a line following the axis of the radial shaft is constructed by determining the centre of the radial shaft in two locations (line A). Second, a line is created by connecting the edges of the radial head (line B). The angle alpha between the two lines is the angle of the radial head towards the radial shaft. The radial head-shaft angle is defined as the opposite angle to alpha