USING ABDUCTION AND EXTERNAL ROTATION OF THE SHOULDER TO INCREASE THESENSITIVITY OF MR ARTHROGRAPHY IN REVEALING TEARS OF THE ANTERIOR GLENOID LABRUM

OBJECTIVE. The purpose of this study was to compare oblique axial MR a rthrograms obtained with the patient's shoulder in abduction and exter nal rotation (ABER) position with conventional axial MR arthrograms ob tained with the patient's arm in neutral position and the shoulder not rotated in revealing tears of the anterior glenoid labrum (AGL). SUBJ ECTS AND METHODS. MR arthrography of the shoulder that included an add itional oblique axial imaging sequence with the patient in the ABER po sition was performed in 256 patients, Assessment of AGL integrity with patients in both conventional axial and ABER positions was made befor e surgery, These assessments were compared with the surgical findings. RESULTS. Of the 92 patients who underwent surgery, AGL tears were fou nd in 27, Conventional axial MR arthrograms revealed 13 tears (sensiti vity, 48%; specificity, 91%). A separate review of MR arthrograms obta ined with patients in the ABER position revealed 24 tears (sensitivity , 89%; specificity, 95%), Reviewed together, axial MR arthrograms and MR arthrograms obtained with patients in the ABER position revealed 26 tears (sensitivity, 96%; specificity, 97%). CONCLUSION. Oblique axial MR arthrograms obtained with the patient's shoulder in the ABER posit ion were significantly more sensitive in revealing AGL tears (p = .005 ) than were conventional axial MR arthrograms obtained with the patien t's arm in a neutral position and the shoulder not rotated.