MRI of the rotator interval of the shoulder

The rotator interval of the shoulder joint is located between the distal edges of the supraspinatus and subscapularis tendons and contains the insertions of the coracohumeral and superior glenohumeral ligaments. These structures form a complex pulley system that stabilizes the long head of the biceps tendon as it enters the bicipital groove of the humeral head. The rotator interval is the site of a variety of pathological processes including biceps tendon lesions, adhesive capsulitis and anterosuperior internal impingement. This article describes the anatomy, function and pathology of the rotator interval using magnetic resonance imaging (MRI).