Superior & middle glenohumeral ligament anatomy and lesions

Recognition of acute & chronic GHL lesions is important in the preoperative work-up of shoulder instability and trauma. Our experience of SGHL and MGHL injuries is based on CTA and MRA performed in young patients with unstable shoulders and compared retrospectively to arthroscopy. Both ligaments are best visualized on axial or sagittal oblique images. The SGHL complex comprises an anterior limb (CHL – SGHL – CGL), a posterior limb (so-called Posterior SGHL). Both limbs merge with the rotator cable (the Rotator cable appearing as a thin line of intermediate signal interposed between cartilage of humeral head and supraspinatus tendon on MR images). A normal SGHL runs almost straight from the superior labrum in the direction of the coracoid process. In a partial humeral avulsion tear, the SGHL could appear frayed and detached from the humeral head with a torn and displaced flap interposed between biceps and subscapularis tendons. On sagittal images, a thickened structure with inhomogeneous signal could be described associated to a synovitis of the rotator interval. A normal MGHL originates most commonly from the anterior portion of labrum. It presents the greatest variation in size and attachment. It could be cordlike with triangular or rounded appearance or duplicated. A sprained MGHL can present an irregular outline with a more oblong appearance on axial views or appears undulated with a more vertical course on sagittal views, indicating an elongation. In a midsubstance rupture of MGHL, the medial stump can remain attached to the labrum; the lateral stump is found between subscapularis tendon and humeral head. A torn MGHL may appear as absent with an open and broad rotator interval (between CHL and subscapularis tendon). Think of a normal variation especially in an isolated finding. But normal variations can have clinical impact. Take home points: Recognition of acute & chronic SGHL & MGHL lesions is important in the preoperative work-up of shoulder instability and trauma. Both ligaments are best visualized on axial or sagittal oblique images. Think of a normal variation especially in an isolated finding.