抄録
The purpose of this study was to investigate the utility of MR imaging of shoulders in abduction and external rotation positions (ABER method) for evaluating the anterior inferior glenohumeral ligament (AIGHL). Nineteen shoulders (8 with traumatic anterior instability; 3 throwing shoulders; 8 normal contralateral shoulders) were examined by 3D-FT gradient echo sequences (TR = 100, TE = 15, flip angle = 15, thickness = 2mm) using a superconducting MR imager (1.5T, Shimadzu Corporation). The subjects' mean age was 24.2 years (range 16-44 years). Axial scapular images were taken in ABER position (with hand on back of head in 135° abduction) and compared to usual hand-down plain images or hand-down MR arthrograms (15ml of 0.5% lidocaine). MR arthrography was performed on the injured side only. In 9 of the 11 injured shoulders, the ABER images were equivalent to the hand-down plain images or hand-down MR arthrograms, in terms of detecting Bankart lesions and anterior capsular low signal band. In 7 of the 11 injured shoulders, the ABER images showed an anterior capsule low signal band continuity, with a similar continuity observed in MR arthrograms as well. The ABER images of every normal shoulder also showed a low signal band continuity. We have previously reported that shoulders with traumatic anterior instability showed low signal band continuity in MR arthrography have a wide and thick AIGHL, as demonstrated by arthroscopy, and represent good indication for an arthroscopic Bankart repair. These findings suggest the potential of MR imaging with the ABER method for AIGHL evaluation, even without an MR arthrography.
