Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Radiol. Sep 28, 2011; 3(9): 224-232
Published online Sep 28, 2011. doi: 10.4329/wjr.v3.i9.224
Magnetic resonance imaging in glenohumeral instability
Manisha Jana, Shivanand Gamanagatti
Manisha Jana, Department of Radiodiagnosis, All India Institute of Medical Sciences, Ansari Nagar, 110029 New Delhi, India
Shivanand Gamanagatti, Department of Radiology, JPNA Trauma Centre, All India Institute of Medical Sciences, Ansari Nagar 110029 New Delhi, India
Author contributions: All authors have equally contributed to the manuscript drafting, manuscript revision and final manuscript checking.
Correspondence to: Dr. Shivanand Gamanagatti, Associate Professor, Department of Radiology, JPNA Trauma Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
Telephone: +91-11-26594567 Fax: +91-11-26588641
Received: April 9, 2011
Revised: July 28, 2011
Accepted: August 4, 2011
Published online: September 28, 2011

The glenohumeral joint is the most commonly dislocated joint of the body and anterior instability is the most common type of shoulder instability. Magnetic resonance (MR) imaging, and more recently, MR arthrography, have become the essential investigation modalities of glenohumeral instability, especially for pre-procedure evaluation before arthroscopic surgery. Injuries associated with glenohumeral instability are variable, and can involve the bones, the labor-ligamentous components, or the rotator cuff. Anterior instability is associated with injuries of the anterior labrum and the anterior band of the inferior glenohumeral ligament, in the form of Bankart lesion and its variants; whereas posterior instability is associated with reverse Bankart and reverse Hill-Sachs lesion. Multidirectional instability often has no labral pathology on imaging but shows specific osseous changes such as increased chondrolabral retroversion. This article reviews the relevant anatomy in brief, the MR imaging technique and the arthrographic technique, and describes the MR findings in each type of instability as well as common imaging pitfalls.

Keywords: Shoulder joint, Instability, Magnetic resonance imaging, Magnetic resonance arthrogram