Primary osteoarthritis of the shoulder: are there differences in scapular morphology, orientation, and rotator cuff action lines between patients and healthy controls?

Patients with primary OA and glenoid type A barely show differences in scapular morphology and scapulathoracic orientation compared to a healthy control group. In contrast, patients with glenoid type B or C showed significant differences of scapulohumeral centering in glenoid version, humeral offset, and glenoid inclination compared to controls. Furthermore, despite the changes of SSP and ISP angles in type B glenoids, the humeral head stayed centered to the glenoid fossa.