Summary

to introduce a novel test for detecting the leading edge tear of subscapularis (LETS)

Abstract

Purpose

The aim was to introduce a novel test for detecting the leading edge tear of subscapularis (LETS), and determine its diagnostic accuracy in comparison with the other known tests.

Methods

From January 2018 to September 2019, 233 patients who underwent arthroscopic repairs for anterior and superior cuff tears were reviewed. The assessments with a provocative test we have coined as the ‘Scissors sign’ and the other related clinical tests (Belly press, belly off, Napoleon, lift off, internal rotation lag, bear hug tests) were performed preoperatively. These were correlated with the arthroscopic findings. Sensitivity, specificity and areas under receiver operating characteristic (AUC/ROC) curve among others were calculated for each test.

Results

In patients who had the LETS with or without supraspinatus tear, the Scissors sign showed the highest sensitivity (91.4%) with specificity of 81.6%, positive predictive value (PPV) of 80.2% and negative predictive value (NPV) of 92.1%. In contrast, all of the other tests showed less than 50% of sensitivity. In patients with the isolated LETS, the Scissors sign also showed the highest sensitivity (90.3%) with specificity of 81.6%, PPV of 57.1%, and NPV of 96.8%. The Scissors sign for the complete tear of subscapularis (CTS) with or without supraspinatus tear, and for the isolated CTS had the sensitivity of 73.1% and 75% respectively. The AUC/ROC of the Scissors sign was the highest in patients with the LETS with or without supraspinatus tear and with the isolated LETS (0.865 and 0.860, respectively).

Conclusions

The Scissors sign is a novel provocative test that can be helpful in the diagnosis of subscapularis tear, especially of the LETS with its relatively high sensitivity and diagnostic accuracy in comparison with the other well-known tests. In combination with the other tests, the Scissors sign will be a good screening tool.