Inferior inclination of the reverse total shoulder baseplate reduces the risk of component loosening, scapular notching, and limited range of motion.
The authors of The reverse shoulder arthroplasty angle: a new measurement of glenoid inclination for reverse shoulder arthroplasty, point out that the key to achieving inferior inclination is to recognize that (1) the baseplate should be placed on the inferior Aspect of the bony-glenoid
(2) Preoperative Inclination inferior The glenoid C-D is different from the inclination (A-B) of the whole glenoid.
The supraspinatus fossa line is a useful reference line to measure glenoid inclination because the sclerotic line of the supraspinatus fossa line is visible on both plain radiographs and CT scans.
They defined the preoperative reverse shoulder arthroplasty angle as the angle between a line perpendicular to a line drawn along the floor of the supraspinous fossa and the plane of the inferior glenoid (A–S) (below right).
The postoperative reverse shoulder arthroplasty angle is the angle between a line perpendicular to a line drawn along the floor of the supraspinous fossa and the plane of the baseplate (below right).
These findings suggest that the ideal inclination for the…