Glenohumeral Ligaments and Unstable Shoulder: CT and MR Arthrography

Background The glenohumeral ligaments are the most important passive stabilizers of the shoulder. The superior (SGHL), middle (MGHL) and inferior (IGHL) glenohumeral ligaments are currently evaluated by shoulder arthroscopy. To avoid surgery as a diagnostic procedure, optimization of MR imaging parameters could help to detect lesions of the glenohumeral ligament complexes. Recognition of acute and chronic glenohumeral ligament pathologies is important for the preoperative evaluation of the unstable and/or traumatic shoulder. Clinical classification of instability is made by the degree, direction, chronology, etiology and the associated lesions. The degree of instability can be divided in dislocation, subluxation and microinstability. The direction can be anterior, posterior or multidirectional. Etiology can be traumatic or atraumatic (voluntary) [2, 3].