The Arthroscopic “Bellows” Sign Identifies Hidden Rotator Cuff Tears

The intraoperative recognition of rotator cuff tears continues to be a challenge in some cases, despite clinical suspicion, a physical examination suggesting a rotator cuff tear, and detection on preoperative imaging studies. Intraoperative identification can be elusive in partial tears including intratendinous tears and obscured full-thickness tears. The purpose of this Technical Note, and the associated technique video, is to discuss a visual sign for the detection of various rotator cuff tear pathologies. Derived from the dynamic fluid expansion and contraction of the affected tissues, this indicator is termed the arthroscopic “bellows” sign.