Rotator interval

The rotator interval is a triangular anatomical area in the anterosuperior aspect of the shoulder bounded superiorly by the anterior margin of the supraspinatus tendon, and inferiorly by the superior margin of the subscapularis tendon, and ranging from the coracoid process to the biceps groove. 

It is better to describe it as a triangular-shaped space instead of a two-dimensional ‘area’: the joint capsule is the as a ceiling and he floor of this space is the articular surface of the humeral head. At the capsuloligamentous level, the roof of this space is formed by the anterior part of the superior complex (the superior glenohumeral ligament and coracohumeral ligament). The inferior border of the rotator interval is formed by the middle glenohumeral ligament.

The rotator interval contains several important anatomical structures that contribute to the stability and normal function of the shoulder joint, including biceps tendon, coracohumeral ligament, superior glenohumeral ligament, rotator interval capsule, anterior fibers of the supraspinatus tendon, and superior fibers of the subscapularis tendon. The rotator interval allows the biceps tendon to become intra-articular as it runs to the superior labral insertion.