1) Understand and be able to recognize the MR imaging appearance of lesions of anterior and posterior instability of the glenohumeral joint. 2) Understand the anatomy of the rotator interval and to recognize the lesions of "micro-instability. 3) Understand the various injuries that occur in the overhead (throwing) athlete and to be able to recognize these injuries on MR imaging. 4) Recognize on MR imaging the common postoperative complications following shoulder reconstruction for glenohumeral instability.
The glenohumeral joint is an intrinsically unstable joint and MR imaging is a very effective noninvassive means of evaluating for the numerous lesions of instability.
The standard MR imaging protocols and use of MR arthrography will be discussed.
I. There are numerous osseous and soft tissue lesions which can occur in conjunction with anterior and posterior shoulder instability including:
-Bankart lesion
-Perthes
-Anterior labroligamentous periosteal sleave avulsion injury
-Osseous Bankart/Hill Sachs lesions
-Humeral avulsion of the glenohumeral ligament
-Glenolabral articular disruption
II. Lesions of Micro-instability refers to instability lesions which occur within the superior aspect of the glenohumeral joint and include:
-SLAP lesions/SLAC lesions
-Rotator interval lesions
-Biceps anchor and pulley lesions
III. Injuries that are commonly seen in overhead (throwing) athletes include:
-Extrinsic impingement-instability overlap
-Labral and rotator cuff injuries resulting from distraction forces
-Internal impingement
-Glenohumeral internal rotation deficit disorder
IV. Postoperative shoulder complications include:
-Breakdown of labral repair/recurent labral tear
-Hardware complications
-Chondrolysis of the glenohumeral joint
Sanders, T,
MRI of Instability Excluding SLAP Lesions. Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL.
http://archive.rsna.org/2013/12020094.html
