Background: In osteoarthritis of the shoulder, the tilt of the
glenoid surface undergoes an eccentric deformation not only in the
anteroposterior but also in the superoinferior direction. The goals of this
study were to analyze glenoid version in the coronal plane and to clarify the
relationship between retroversion and inferior inclination of the glenoid.
Methods: Standardized radiographs of 100 consecutive patients with
primary osteoarthritis of the shoulder and 100 otherwise healthy patients with
shoulder pain (the control group) were included in this study and were
analyzed by two independent observers.
Results: We defined four different types of inclination deformity of
the glenoid. In a type-0 glenoid, a line at the base of the coracoid process
and a line at the glenoid rim run parallel. Both lines intersect below the
inferior glenoid rim in a type-1 glenoid. In a type-2 glenoid, the line at the
base of the coracoid process and the glenoid line intersect between the
inferior glenoid rim and the center of the glenoid. In a type-3 glenoid, the
lines intersect above the base of the coracoid process. A significant
difference (p < 0.0001) in the distribution of glenoid types between the
two patient groups was observed. Forty-seven patients with osteoarthritis
showed combined posterior and inferior glenoid wear. We found no correlation
between the type of inclination and the type of glenoid morphology. The
interobserver reliability of our observations was very high.
Conclusions: In osteoarthritis, eccentric inferior glenoid wear is
frequent and independent from retroversion deformity of the glenoid.
Normalization of glenoid version in both transverse and coronal planes may
reduce eccentric loading of the prosthetic glenoid, which has been associated
Clinical Relevance: This radiographic classification system can
facilitate the decision-making process to normalize glenoid inclination during