Accuracy of magnetic resonance imaging in determining the presence and size of recurrent rotator cuff tears.

We attempted to assess the accuracy of magnetic resonance imaging (MRI) in determining the size of recurrent cuff tears in correlation with size measured at surgery. Thirty-seven shoulders in 33 patients who had reoperation for a presumed failed rotator cuff repair were retrospectively evaluated. All patients had preoperative MRI, the results of which were read by a musculoskeletal radiologist to determine the presence of a tear and to estimate its size. All tears were measured intraoperatively in sagittal and coronal planes. Thirty-three shoulders had recurrent tears of the rotator cuff, and MRI correctly identified the presence of 30 of them. MRI correctly identified only 1 of the 4 patients without a recurrent tear of the cuff. The correlation coefficient for MRI accurately defining the size of cuff tears was 0.46. The sensitivity of MRI for the diagnosis of retear was 91%, and the specificity was 25%. MRI is accurate in diagnosing a recurrent full-thickness cuff tear in postsurgical shoulders. However, it is relatively inaccurate in correctly defining the size of the tear. MRI also has a tendency to overdiagnose cuff tears in postsurgical patients with continued pain and symptoms.