Posterior sentinel sign of the biceps tendon as an arthroscopic indicator of supraspinatus tears

INTRODUCTION Magnetic resonance imaging (MRI) is highly accurate for diagnosing full-thickness rotator cuff tears but inaccurate to detect small anterosuperior cuff tears near the rotator interval. Expanding on the concepts of long head of biceps tendon (LHBT) instability and the anterior sentinel sign, the present study evaluated the posterior sentinel sign, a novel arthroscopic indicator of supraspinatus tears. METHODS This monocentric prospective cohort study included patients undergoing arthroscopic repair of rotator cuff tears at a single institution. The integrity and stability of the LHBT were assessed intra-articularly for abrasion, delamination, or partial tears. Sentinel signs were classified as anterior or posterior based on their location on the LHBT. Rotator cuff tears were evaluated, and their correlation with sentinel signs was analyzed using Chi-Square test. To evaluate the diagnostic value of the sentinel signs, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) were calculated. RESULTS This study included 69 patients. The posterior sentinel sign was observed in 21/39 patients with supraspinatus tears (53.8%) and in 1/30 patient without (3.3%), showing a significant association (X 2 = 19.9, p