All shoulder arthroplasty candidates with glenohumeral osteoarthritis will be receiving both 3D computed tomography (CT) and 3D non-contrast magnetic resonance (MR) imaging.

MRI is performed using 3T scanners with a dedicated 16-channel shoulder array coils. The MRI sequences include 3-mm slice thickness and 0.5-mm gap width with a field of view of 14 or 15 cm. There were 6 diagnostic sequences with axial, coronal, and sagittal proton density weighting as well as coronal T2 with frequency selective fat suppression and sagittal T1 images.

All scans from 3D CT and 3D MR imaging were reviewed carefully for the presence of any morphological changes. For the determination of glenoid version, a line was drawn between the anterior and posterior margins of the glenoid. The transverse axis of the scapula was determined by a line drawn from the midpoint of the genoid fossa to the medial end of the image of the scapula; a line drawn perpendicular to this was defined as a line of neutral version. The angle between the line of neutral version and the line connecting the anterior and posterior margins of the glenoid was measured and recorded as the Glenoid Version.

The 3D MRI glenoid inclination is measured by the two observers with the same method used for CT 3D glenoid inclination measurement following generating a new 2D axial MR images form the 3D MRI model using the three-point method. A line on the supraspinatus fossa and 3 points are drawn: Point S represents the inferior border of the glenoid, point R represents the intersection of the supraspinatus fossa line with the glenoid surface, and point A represents the vertex of the right triangle created by the line of the supraspinatus fossa and a perpendicular line passing through point S; this line (RS) is the hypotenuse of the right triangle. The inclination corresponds to the area in which the glenoid component of RSA is implanted.

3D computed tomography (CT) and 3D non-contrast magnetic resonance (MR)

3-dimensional (3D) magnetic resonance (MR): MRI is performed using 3T scanners with a dedicated 16-channel shoulder array coils. The MRI sequences include 3-mm slice thickness and 0.5-mm gap width with a field of view of 14 or 15 cm. There were 6 diagnostic sequences with axial, coronal, and sagittal proton density weighting as well as coronal T2 with frequency selective fat suppression and sagittal T1 images.

3D computed tomography (CT) imaging: The CT protocol consists of 3-mm axial images of the glenoid reconstructed into 1-mm sagittal and coronal 2D reconstructions using the following parameters: 120 kV, 280 mA, and pitch of 0.9. The CT data were also used to produce a 3D reconstruction of each glenoid.

All scans from 3D CT and 3D MR imaging were reviewed carefully for the presence of any morphological changes. For the determination of glenoid version, a line was drawn between the anterior and posterior margins of the glenoid. The transverse axis of the scapula was determined by a line drawn from the midpoint of the genoid fossa to the medial end of the image of the scapula; a line drawn perpendicular to this was defined as a line of neutral version. The angle between the line of neutral version and the line connecting the anterior and posterior margins of the glenoid was measured and recorded as the Glenoid Version.

3D computed tomography (CT) and 3D non-contrast magnetic resonance (MR)

3-dimensional (3D) magnetic resonance (MR): MRI is performed using 3T scanners with a dedicated 16-channel shoulder array coils. The MRI sequences include 3-mm slice thickness and 0.5-mm gap width with a field of view of 14 or 15 cm. There were 6 diagnostic sequences with axial, coronal, and sagittal proton density weighting as well as coronal T2 with frequency selective fat suppression and sagittal T1 images.

3D computed tomography (CT) imaging: The CT protocol consists of 3-mm axial images of the glenoid reconstructed into 1-mm sagittal and coronal 2D reconstructions using the following parameters: 120 kV, 280 mA, and pitch of 0.9. The CT data were also used to produce a 3D reconstruction of each glenoid.