Diagnostic performance of clinical tests for subscapularis tendon tears.

Abstract

Tears of the subscapularis (SSC) tendon constitute a diagnostic challenge. The purpose of the present study was to evaluate the diagnostic capabilities of five clinical SSC tests. Five established clinical tests were evaluated in 106 consecutive patients prior to shoulder arthroscopy. The tests included the Lift Off Test, Internal Rotation Lag Sign, Belly Press Test, Belly Off Sign, and Bear Hug Test. The integrity of the SSC tendon at surgery was used as the gold standard. Lesions to the SSC were graded according to Fox and Romeo. There were 32 SSC lesions accounting for an incidence of 30.2%. The sensitivity for all tests was 0.66, while the specificity was 0.82. For all tests, positive tests results were found to be dependent on subscapularis integrity (p<0.001, respectively). The sensitivity for any type of SSC lesion for the Lift Off Test, Internal Rotation Lag Sign, Belly Press Test, Belly Off Sign, and Bear Hug Test was 0.35, 0.41, 0.34, 0.31, and 0.52, respectively. Specificity was found to be 0.98, 0.91, 0.96, 0.97, and 0.85, respectively. If only grade 2-4 tears were analysed, sensitivity was 0.32, 0.42, 0.37, 0.37, and 0.72 and specificity 0.94, 0.86, 0.92, 0.94, and 0.84. A positive correlation was found between the number of positive tests and the severity of the SSC lesions. In the present study, the Bear Hug Test was found to have the highest sensitivity of all tests studied, especially for tears of the upper tendon border. It appears advisable to perform more than one clinical subscapularis test to further improve sensitivity. Nevertheless, SSC tears may still escape clinical recognition. Therefore, a high index of suspicion has to be maintained in order not to miss SSC tears. Diagnostic study, Level I.