Sentinel sign: a sign of biceps tendon which indicates the presence of subscapularis tendon rupture.

PURPOSE

Subscapularis tendon ruptures, which are small in size, can be missed on CT or MRI imaging and are also difficult to diagnose by arthroscopy. Here we discuss a new sign of biceps tendon, which may point towards rupture of the subscapularis tendon. The biceps tendon may have scuffing, abrasion or partial tear of its anterior portion. We have named this as sentinel sign as it signals the presence of a coexisting subscapularis rupture.

MATERIALS AND METHODS

This study was a retrospective analysis of available arthroscopic rotator cuff repair surgery videos of 2009-2010. The videos were studied, and data recorded for number of cases showing the presence of sentinel sign and coexisting subscapularis rupture. Sensitivity, positive predictive value of the sign, was calculated.

RESULTS

Out of 330 available videos, 79 showed the presence of subscapularis rupture. Ten patients had a positive sentinel sign, but an intact biceps pulley that obscured the visualisation of the subscapularis tendon tear. This tear became apparent after removal of anterior part of biceps sling.

CONCLUSION

The presence of sentinel sign of the biceps tendon indicates the presence of a coexistent subscapularis rupture. If the rupture is not apparent, obscuring parts of the biceps sling should be removed to see the upper fibres of subscapularis tendon.

LEVEL OF EVIDENCE

Study of diagnostic test, Level III.