Bubble Sign to Confirm the Integrity of the Shoulder Rotator Cuff.

The presence of an intra-articular air bubble adjacent to the rotator cuff at the time of diagnostic shoulder arthroscopy will confirm an intact rotator cuff and is helpful in ambiguous cases. After the introduction of the arthroscope, air is pulled owing to negative air pressure in the joint cavity. Fluid inflow is then started after the inflow has been properly flushed of all air. This creates an intra-articular air bubble, which can be found at the top of the capsular-supraspinatus attachment site in cases with an intact rotator cuff. Secondary subacromial positioning of the arthroscope is used to confirm the intact rotator cuff from the bursal side.