Diagnostic Value of Clinical Tests for Supraspinatus Tendon Tears

Abstract

Purpose: The purpose of this study was to analyze the diagnostic value of 7 clinical tests for the diagnosis of supraspinatus tendon tears, to investigate the ability of these tests to distinguish between partial- and full-thickness tears, and to compare 3 different ways of interpreting positive test results (weakness and pain): (1) in case of pain, (2) in case of weakness, regardless if with pain or not, and (3) when any of the 2 symptoms occurs, regardless if in combination or not. Moreover, this study aimed to investigate whether a combination of tests can improve the diagnostic accuracy.

Methods: A total of 115 consecutive patients who presented with different shoulder symptoms were prospectively enrolled in the study from March 2015 to April 2017. The inclusion criterion was that a shoulder arthroscopy was scheduled. Patients with the following characteristics were excluded from the study: patients (1) with shoulder instability, (2) with adhesive capsulitis, or (3) with any history of previous shoulder surgery including rotator cuff repair or patients (4) who did not provide informed consent. To assess the sensitivity, specificity, positive and negative predictive values, accuracy, diagnostic odds ratio, positive and negative likelihood ratio, and area under the curve (AUC) of each test, the intraoperative findings were compared with the results of the preoperative clinical examination of 7 established clinical tests: the empty can test, the full can test, the zero-degree abduction test, the Whipple test, the scapular retraction test, the drop arm test, and the modified drop arm test.

Results: A significant correlation was found between the findings for the empty can (P = .004) and full can (P = .001) tests and the intraoperative findings, wherein the full can test achieved better AUC. Muscle weakness showed the best diagnostic precision compared with pain or using both criteria. No single clinical test was found to be useful to distinguish between partial- and full-thickness tears. A combination of at least 3 or more tests improved the diagnostic value. The combination of the empty can, the full can, and the zero-degree abduction tests showed the best AUC (0.795) and correlation with the intraoperative findings (P = .02).

Conclusions: The results of the present study indicate that of all clinical tests studied, only the empty can and full can tests were effectively able to diagnose tears of the supraspinatus tendon accurately. The greater AUC and correlation with the arthroscopic findings suggest that muscle weakness should be considered the gold standard when interpreting the test results. Furthermore, the present study showed that the analyzed tests are not capable of distinguishing between partial- and full-thickness tears of the supraspinatus tendon and that the combination of at least 3 tests, including the empty can, the full can, and the zero-degree abduction tests, improved the diagnostic value significantly. In addition, the empty and full can tests have showed higher diagnostic precision and fair AUC when supraspinatus tendon tears were more than 1 cm in size.

Level of evidence: Level 1, diagnostic study.