Fig. 4.

Saggital view—screw-equator angle. The angle measured between the equatorial line (yellow horizontal line perpendicular to yellow vertical line between superior and inferior glenoid pole—12 and 6 o’clock) and the axis of the screw (red line). Cronbach’s α for the screw-equator angle (0.61 for intra-rater and 0.77 for inter-rater) implies this measurement is unreliable. Due to the complex shape of the glenoid and alterations of the anterior glenoid rim in shoulder instability, it is difficult to achieve the exact same image for repeated measurements. Despite this fact, no correlation was found between this parameter and other clinical and radiological results. To our knowledge, this parameter value was not yet reported in the literature