The "paraglider-wing" sign: an arthroscopic indicator of partial-thickness bursal-surface tears of the supraspinatus tendon.

Partial-thickness bursal-surface tears of supraspinatus tendon may be missed on preoperative investigations and can be overlooked at surgery if not specifically sought. The authors describe an arthroscopic sign to detect these tears, when they involve more than half the tendon fibres, from the articular-side of the joint. The "paraglider-wing" sign, visualized during diagnostic glenohumeral arthroscopy, is demonstrated as an upward bulge of the capsulo-tendinous layer through the bursal-surface tear, under pressure of the inflow fluid. A positive sign indicates (1) presence of a partial-thickness bursal-side tear of the supraspinatus tendon, (2) significant depth (stage II or III) of the tear, and (3) the medial extent of the tear along the length of the tendon. A meticulous subacromial bursoscopy and excision of the bursa is then performed to visualize the tear from the subacromial space. Repair of the tear is performed with a double-row suture anchor fixation technique; the medial row of sutures is passed through the intact region of the tendon using the "paraglider-wing" sign as a guide.