Figure 2 Receiver operating characteristic (ROC) curve for critical shoulder angle (CSA). A cutoff point for CSA was calculated, and patients with CSA values of 36 and above had a sensitivity of 73.58%, specificity of 74.47%, positive predictive value of 75%, and negative predictive value of 74.47% for detecting full thickness rotator cuff tear. The area under the ROC curve was 77.4%, with a standard error of 4.6 (Number Cruncher Statistical System 2007; Kaysville, Utah, USA).