Diagnosis of classification of SLAP lesion with MR arthrography

To determine the accuracy of MR Arthrography (MRA) in the classification of super labrum anterior posterior (SLAP) lesions, we investigated 15 patients (15 men, average 27.5 years) who underwent MRA before arthroscopic operation from 1998 to 2001. Based on the Snyder's classification, we defined the diagnostic criteria for classification of SLAP lesion on MRA: Type I shows irregularity of the labrum, without evidence of detachment from the superior glenoid rim. Type II shows complete detachment of the bicipital-labral complex. Type III shows detachment and inferior displacement of the superior labrum. Type IV shows Gd-DTPA dissecting into the biceps tendon. MRA findings correlated with arthroscopic findings. In MRA, 4 patients were diagnosed as type I, 10 type II, and 1 type IV. But in surgical findings, 3 out of the 4 patients diagnosed as type I were type II, and 3 out of the 10 patients (type II) were type I. MRA had a sensitivity of 25%, specificity of 73%, accuracy of 60% in type I, and sensitivity of 70%, specificity of 40%, accuracy of 60% in type II. The MRA classification corresponded with those of arthroscopy in 9 out of 15 patients (60%). MRA is a useful technique in the diagnosis of SLAP lesion, but classification is still difficult. (author)