In the glenohumeral joint at rest, the coracohumeral and superior glenohumeral ligaments resist inferior translation. Once the arm is abducted to 90 degrees, which structure becomes the primary static restraint against anteroinferior dislocation?

• A Inferior glenohumeral ligament complex ✓
• B Superior labrum
• C Coracoacromial ligament
• D Long head of triceps origin

Explanation

At 90 degrees of abduction the inferior glenohumeral ligament complex shifts inferiorly to form a hammock beneath the humeral head, becoming the main static stabiliser against anteroinferior translation. Its glenoid detachment produces the Bankart lesion seen after anterior dislocation. The coracohumeral and superior glenohumeral ligaments act mainly with the arm adducted, which kills those distractors.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.