Objective    To assess the relationship between anterior-inferior glenohumeral instability and glenoid version.     Methods    Both shoulders in 24 patients with unilateral anterior-inferior glenohumeral instability were scanned with multiplanar spiral CT scanner (MSCT). The scapula and the humerus were reconstructed by the volume rendering technique and multiplanar reformation in 4 slices on axial plane from glenoid top to its bottom. The scapular glenoid version angles of 24 patients were measured bilaterally in 4 levels

and compared bilaterally by statistic analysis.     Results    From the top to the bottom

the scapular glenoid ve

rsion angle in the side with anterior-inferior glenohumeral instability was respectively (-15.24±10.18)°

(-8.22±8.47)°

(-2.88±4.56)°  and (-2.49±6.43)°

while the angle in the healthy side was respectively (-15.07±12.11)°

(-10.63±7.25)°

(-6.04±3.61)°  and (-5.26±3.02)°. Only the difference at the 4

th

plane was significant between the healthy side and the affected side (P0.05).     Conclusion    The glenoid version angle may be directly related with the anterior-inferior glenohumeral instability. The glenoid version angle measurement would be helpful to stability evaluation

surgery choice and prognosis.