Rotator Interval Complex

intervallum musculorum rotantium

The rotator interval is the triangular gap in the anterior rotator cuff between the supraspinatus superiorly and the subscapularis inferiorly, through which the long head of biceps tendon passes. The interval is bridged by the coracohumeral ligament (CHL) and the superior glenohumeral ligament (SGHL), which together form a pulley that stabilises the biceps tendon at the entrance to the bicipital groove. The rotator interval also contains the anterior capsular recess.

Region: Shoulder

Clinical Relevance

Clinical Notes

Rotator interval pathology is central to two common shoulder conditions: adhesive capsulitis (frozen shoulder) — where the rotator interval CHL and SGHL become contracted and thickened, limiting external rotation and elevation; and biceps instability — where interval disruption allows medial subluxation of the long head biceps off the bicipital groove. Rotator interval closure (RI plication) reduces shoulder laxity in thermal capsulorrhaphy and in open instability surgery. RI release in arthroscopic capsular release for frozen shoulder restores external rotation. MRI arthrogram evaluates the CHL and SGHL as contrast filling the RI recess.

Pathology

Common Injuries & Conditions

Rotator Interval Contracture in Adhesive Capsulitis

Inflammation and subsequent fibrosis of the coracohumeral and superior glenohumeral ligaments within the rotator interval produce the progressive external rotation and elevation loss of frozen shoulder; arthroscopic release of the rotator interval CHL and SGHL as the first step in capsular release restores external rotation and sets up the remainder of the arthroscopic capsulotomy.