Diagnostic value of the axial view of magnetic resonance imaging to identify two-dimensional shapes of full-thickness rotator cuff tears

Background Coronal and sagittal views of magnetic resonance imaging (MRI) were used to determine rotator cuff tear size and fatty infiltration, but these images were not enough to identify the tear shape. Purpose To correlate the preoperative axial MRI views and arthroscopic surgical findings to identify the two-dimensional shapes in rotator cuff tears. Material and Methods This study included 166 patients who underwent arthroscopic repair between 2015 and 2018. Preoperative coronal, sagittal, and axial MRI views were evaluated for tear size and geographic configuration in axial sections, and the length and the width were measured and were matched with arthroscopic surgical views by lateral portals. Results The agreement of axial MRI views with the arthroscopic view was 88.0% in crescent, 97.2% in longitudinal, 78.6% in massive, and 100% in rotator cuff tear arthropathy. The mean agreement rate of axial MRI views with arthroscopic view was 81.9%. Mean mediolateral and anteroposterior tear sizes on axial MRI were 16.68 mm and 19.33 mm, respectively. Mean mediolateral and anteroposterior tear sizes by arthroscopic view were 21.49 mm and 21.04 mm, respectively. Tear sizes by MRI axial images were 71.3% of arthroscopic view. SST/IST degenerative changes were noted in most patients with massive tears and rotator cuff arthropathy (P = 0.001). Conclusion Rotator cuff tear shape on preoperative axial MRI view had close agreement (81.9%) with arthroscopic findings by lateral portal, and tear size by preoperative axial MRI views was 71.3% of that of arthroscopic view. Axial MRI views helped to predict the geometric tear shape of rotator cuff tears.