The supraspinatus distension sign: an indicator of supraspinatus integrity

To determine if direct contact between the biceps tendon and supraspinatus in patients undergoing shoulder arthroscopy performed in the lateral decubitus position has predictive value in evaluating full-thickness and articular-sided, partial-thickness rotator cuff tears.

Five hundred sixty-three consecutive shoulder arthroscopies in the lateral decubitus position were performed by a single surgeon between September 2005 and September 2007. The presence or absence of distance between the biceps tendon and supraspinatus was evaluated upon entering the joint. A diagnostic arthroscopy of the glenohumeral and subacromial spaces then ensued to determine the presence and extent of rotator cuff tear.

The biceps-supraspinatus interval was preserved in 211 of 232 (90.9%) of the articular-sided, partial-thickness tears. The biceps-supraspinatus space was absent in 76 of 77 (98.7%) of the full-thickness tears. After excluding cases of concomitant adhesive capsulitis, all 211 articular-sided, partial-thickness rotator cuff tears and only 1 of 75 (1.3%) full-thickness rotator cuff tears was associated with a preserved biceps-supraspinatus interval (false negative).

Our study further validates the high sensitivity and specificity of using the loss of supraspinatus distension for predicting full-thickness rotator cuff tears. We also report the reliable preservation of supraspinatus distension with articular-sided, partial-thickness rotator cuff tears. These articular-sided partial-thickness tears typically do not lead to sufficient egress of arthroscopic fluid from the glenohumeral joint to cause a loss of supraspinatus distension.

Level IV, prognostic case series.