Superior labrum anterior-posterior (SLAP) tears: Evaluation of three MR signs on T2-weighted images

PURPOSE: To compare the sensitivity and specificity of three magnetic reson ance (MR) imaging signs for the diagnosis of superior labrum anterior-poste rior (SLAP) tears. MATERIALS AND METHODS: The study involved 23 consecutive patients with a ty pe 2, 3, or 4 SLAP tear at arthroscopy and 31 age-matched control patients with an arthroscopically normal or type 1 SLAP lesion. The superior labrum was evaluated oh MR images for high signal intensity extending to the artic ular surface in the posterior third of the labrum, an irregular or laterall y curved area of high signal intensity, or two,high-signal-intensity lines. RESULTS: The sensitivity, specificity, and accuracy of posterior high signa l intensity for a type 2, 3, or 4 SLAP tear were 48%, 94%, and 74%, respect ively, for observer 1 and 61%, 81%, and 72%, respectively, for observer 2. For laterally curved area of high signal intensity, these values were 65%, 84%, and 76%, respectively, and 56%, 84%,:and 72%, respectively. For two hi gh-signal-intensity lines, these values were 17%, 94%, and 61%, respectivel y, and 13%, 94%, and 59%, respectively. For the presence of either posterio r or laterally curved high signal intensity, the sensitivity was 65% for bo th observers, whereas the specificity was 84% for observer 1 and 74% for ob server 2. The kappa values for interobserver agreement were 0.60 for poster ior high signal intensity and 0.58 for laterally curved high signal intensi ty. CONCLUSION: Laterally curved and posterior high signal intensities are:spec ific signs for distinguishing a SLAP tear from a normal-variant superior su blabral recess.