Glenoid version and rotator cuff tears.

The purpose of this study was to determine the relationship between rotator cuff (RC) tear and the orientation of the glenoid. Ninety-six shoulders (94 patients) that underwent open RC repair were grouped according to the type of tear. We measured on MRI the acromio-glenoid angle (AG) and the supraspinatus fossa glenoid angle on the anterior-posterior (SGAP) and axial (SGAX) views. RC patients had a smaller AG angle (76+/-7 degrees vs. 86+/-10 degrees ) and a larger SGAP angle (112+/-6 degrees vs. 102+/-7 degrees ) compared to controls (p<0.001). We also found a highly significant difference (p<0.001) in glenoid version measured by SGAX between anterior cuff tears (-5+/-4 degrees ) and posterior cuff tears (3+/-3 degrees ). Furthermore, we identified an association between RC tear and the orientation of the glenoid relative to the axis of the supraspinatus fossa. Greater retroversion is predictive of an anterior cuff injury and greater anteversion is predictive of a posterior cuff injury.