BackgroundThe prevalence of subscapularis (SSC) tendon tears is often underestimated. This negatively impacts the shoulder function because the SSC muscle is a powerful internal rotator. The primary aim of this study was to compare a blended clinical and radiological preoperative index of suspicion for SSC tears to the arthroscopic findings. The secondary aim was to compare the surgeon's and radiologist's index of suspicion to determine which is more accurate. HypothesisAnalyzing a transverse image passing under the tip of the coracoid process, in combination with clinical examination, will be the standard for detecting SSC tears. MethodsThis prospective study enrolled 50 consecutive patients who underwent shoulder arthroscopy. Preoperatively, four clinical tests were doneto detect SSC tears: lift-off, internal rotation lag sign, bear-hug, belly-press. A CT arthrography slice passing under the coracoid process tip was analyzed by the surgeon. The surgeon deduced a radiological index of suspicion for SSC tears then a blended clinical and radiological index of suspicion based on the clinical examination. Lastly, the surgeon looked at the radiologist's findings and index of suspicion for a lesion. The three indexes of suspicion were compared with the actual arthroscopy findings. ResultsThe surgeon's blended clinical and radiological index of suspicion was similar to his radiological index. Both of the surgeon's indexes of suspicion were higher than the radiologist's. The prevalence of SSC tears was 58 %. DiscussionWe recommend doing multiple clinical tests as they complement each other in detecting SSC tears, since each one activates a different portion of the muscle. We advise surgeons to supplement their clinical examination by analyzing a specific image of the tendon below the coracoid, as the reference view for the starting point of SSC tears. Level of evidenceIV, prospective diagnostic study on consecutive patients.