Comparison of Magnetic Resonance Imaging and Computed Tomography Scans of the Glenoid Version in Anterior Dislocation of the Shoulder

The glenoid version is an important factor in the etiology of anterior dislocation of the shoulder and the planning of shoulder surgery. Few reports compare the magnetic resonance imaging (MRI) measurements of the glenoid version with those of computed tomography (CT). This study aimed to show that it is possible to use MRI instead of CT, which is accepted as the gold standard today for the evaluation of the glenoid version. A total of 55 patients with a history of 1 nonsurgically treated unilateral anterior dislocation of the shoulder who had both MRI and CT records for the dislocated shoulders constituted the study group. The glenoid version was measured in the axial plane on MRI and CT. Mean glenoid version measured by the observers was -1.6 degrees +/- 4.7 degrees (95% confidence interval, -2.3 degrees to -0.8 degrees) and -1.8 degrees +/- 4.3 degrees (95% confidence interval, -2.5 degrees to -1.2 degrees) by CT and MRI, respectively (P=.126). The evaluation of the CT and MRI measurements made by the 3 observers (X, Y, and Z) revealed no significant difference, as the P values of X CT - X MRI, Y CT - Y MRI, and Z CT - Z MRI were .550, .406, and .238, respectively. Interclass correlation among the 3 observers for CT and MRI was 0.996 and 0.981, respectively. The imaging methods of MRI and CT can be interchangeably used in the evaluation of the glenoid version in cases of anterior dislocation of the shoulder.