It is still unknown whether glenoid inclination or lateral acromial roof extension is a more important determinant for development of rotator cuff tears (RCT) or osteoarthritis (OA) of the shoulder.

It was the purpose of this study, to evaluate whether there is a potential predominance of one of these factors in pathogenesis of RCT or concentric OA.

We analyzed 70 shoulders with advanced degenerative RCT and 54 shoulders with concentric OA undergoing primary shoulder arthroplasty (anatomical or reverse) using antero‐posterior radiography and multiplanar computed tomography.

The two groups were compared in relation to glenoid inclination, lateral acromion roof extension, acromial height, and critical shoulder angle (CSA).