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Superior glenohumeral ligament

The superior glenohumeral ligament (SGHL) is the most superior of the three glenohumeral ligaments, located within the shoulder joint capsule. It reinforces the anterior-superior aspect of the glenohumeral joint and plays a key role in stabilizing the humeral head, particularly in the neutral and adducted positions of the arm.

It arises from the supraglenoid tubercle and adjacent glenoid labrum, running obliquely downward and laterally to insert on the lesser tubercle of the humerus and the upper part of the anatomical neck, blending with fibers of the subscapularis tendon and the coracohumeral ligament in the rotator interval.

Synonyms

  • SGHL

  • Superior glenoid-humeral ligament

  • Upper glenohumeral capsular ligament

Origin, Course, and Insertion

  • Origin: Upper pole of the glenoid labrum and adjacent supraglenoid tubercle, just anterior to the origin of the long head of the biceps tendon.

  • Course: Passes obliquely downward and laterally across the rotator interval, lying deep to the coracohumeral ligament and superficial to the joint capsule.

  • Insertion: Attaches to the upper part of the lesser tubercle and the anterior aspect of the humeral neck, blending with the subscapularis tendon fibers.

Relations

  • Superiorly: Coracohumeral ligament and base of the coracoid process

  • Inferiorly: Middle glenohumeral ligament (MGHL)

  • Anteriorly: Subscapularis tendon and joint capsule

  • Posteriorly: Long head of the biceps tendon (within the biceps pulley)

  • Laterally: Lesser tubercle and humeral head articular cartilage

  • Medially: Supraglenoid tubercle and glenoid labrum

Nerve Supply

  • Sensory innervation via articular branches of the suprascapular and axillary nerves

Function

  • Joint stability: Prevents inferior and anterior translation of the humeral head, especially when the arm is adducted.

  • Rotator interval reinforcement: Forms part of the rotator interval capsule, stabilizing the long head of the biceps tendon in conjunction with the coracohumeral ligament.

  • Range control: Limits external rotation when the arm is adducted.

  • Dynamic coupling: Works synergistically with the subscapularis and supraspinatus tendons to maintain humeral head centering.

Clinical Significance

  • Tears or laxity: Can lead to anterior shoulder instability or biceps tendon subluxation.

  • Rotator interval pathology: SGHL often affected with capsular thickening or disruption in adhesive capsulitis and instability syndromes.

  • Biceps pulley lesions: Partial tearing of the SGHL contributes to instability of the long head of the biceps tendon.

  • Impingement and degeneration: Seen in chronic overhead athletes and degenerative shoulder conditions.

  • Imaging relevance: MRI essential for evaluating capsuloligamentous integrity and subtle anterior-superior instability.

MRI Appearance

  • T1-weighted images:

    • Normal ligament: Thin low-signal (dark) band within the superior joint capsule, best seen on oblique sagittal and axial planes.

    • Adjacent marrow: Bright, fatty signal in humeral head and glenoid.

    • Pathology: Discontinuity or thickening of the low-signal band indicates tear or scarring; joint effusion appears bright and outlines ligament margins.

  • T2-weighted images:

    • Normal SGHL: Low-signal intensity band, slightly darker than capsule and surrounding muscle.

    • Joint fluid: Bright hyperintense, delineating the ligament course.

    • Tears or inflammation: Focal high-signal intensity within or around the ligament; discontinuity or nonvisualization may indicate rupture.

    • Associated findings: Fluid tracking along the biceps tendon sheath or rotator interval indicates pulley complex injury.

  • STIR:

    • Normal ligament: Low signal, blending with joint capsule.

    • Pathology: Bright hyperintensity along ligament fibers and periligamentous soft tissue in inflammation or strain.

    • Useful for detecting rotator interval edema and capsular synovitis.

  • Proton Density Fat-Saturated (PD FS):

    • Normal SGHL: Thin dark linear structure seen between the biceps tendon and subscapularis tendon.

    • Partial tear or sprain: Focal bright hyperintensity with irregular contour.

    • Complete tear: Discontinuity or absence of normal low-signal ligament with fluid replacing the expected site.

  • T1 Fat-Sat Post-Contrast:

    • Normal ligament: Minimal or no enhancement.

    • Inflamed or scarred ligament: Shows linear or diffuse enhancement.

    • Chronic instability: Thickened enhancing capsule; adhesive capsulitis shows capsular enhancement around rotator interval.

CT Appearance

Non-Contrast CT:

  • Ligament itself not well visualized due to soft-tissue density similar to capsule.

  • Indirect findings: Joint effusion, capsular thickening, or calcifications at the humeral insertion.

  • Bony avulsions (at glenoid or humeral attachment) visible as small cortical irregularities.

Post-Contrast CT (standard):

  • Enhancing capsule and periligamentous tissues may indicate inflammation or scarring.

  • CT arthrography:

    • Contrast outlines the rotator interval and glenohumeral capsule.

    • Partial or complete ligament tears identified by contrast tracking between subscapularis tendon and biceps anchor.

    • Useful in patients who cannot undergo MRI.

MRI images

Superior Glenohumeral Ligament (SGHL) axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

MRI images

Superior Glenohumeral Ligament AXIAL cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

MRI images

Superior Glenohumeral Ligament sagittal cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000