Joong Mo Ahn MD, PhD, Presenter: Nothing to Disclose

Georges Yousef El-Khoury MD, Abstract Co-Author: Nothing to Disclose

Darus Lee Bennett MA, MD, Abstract Co-Author: Nothing to Disclose

Kenjirou Ohashi MD, Abstract Co-Author: Nothing to Disclose

To determine the relationship between the anterior-posterior contrast filling ratio of the glenohumeral joint and a presence of anterior labrocapsular tear

MR arthrograms of 52 patients with (n=32) or without (n=20) arthroscopically proven anterior labrocapsular tear were analyzed. Anterior labrocapsular tear included Bankart lesion (n=26), ALPSA lesion (n=4), and Perthes lesion (n=2). Patients with a history of prior shoulder surgery, adhesive capsulitis, full-thickness rotator cuff tear, or posterior labrocapsular abnormality were excluded. Anterior-posterior filling ratio was measured on the axial images at the level of 4 o’clock position, using reference lines from the sagittal view on high-resolution workstation. For an anterior filling, the longest dimension of the contrast, filled between the anterior margin of the glenoid and the anterior joint capsule, was measured. For a posterior filling, the longest dimension of the contrast, filled between the cortex of the humeral head and posterior joint capsule, was measured. Then the former was divided by the latter. Neutral position of the glenohumeral joint was ensured during MR arthrography. Measurements of the filling ratio for the patients with and without anterior labrocapsular tear were compared with Mann-Whitney U test.

Significant difference in the filling ratio was present between the patients with and without anterior labrocapsular tear (p < .05). Filling ratio distribution in patients with anterior labrocapsular tear was bimodal and ranged from 0.15 to 0.84 and from 1.46 to 1.70, whereas the filling ratio in patients without anterior labrocapsular tear ranged from 0.78 to 1.33.

Discordant anterior-posterior contrast filling of glenohumeral joint cavity on MR arthrography may suggest a high suspicion of an anterior labrocapsular tear.

Assessment of the capsular distensibility by anterior-posterior filling ratio would improve the detection of the anterior labrocapsular tear.

Ahn, J, El-Khoury, G, Bennett, D, Ohashi, K, Capsular Distensibility of the Glenohumeral Joint during MR Arthrography: An Ancillary Finding for Anterior Labrocapsular Tear.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4433038.html