POSTEROSUPERIOR GLENOID IMPINGEMENT OF THE SHOULDER - FINDINGS AT MR-IMAGING AND MR ARTHROGRAPHY WITH ARTHROSCOPIC CORRELATION

PURPOSE: To determine the utility of magnetic resonance (MR) imaging a nd MR arthrography in the evaluation of arthroscopic findings of poste rosuperior glenoid impingement. MATERIALS AND METHODS: The findings at MR imaging, MR arthrography, and physical examination with the patien t under anesthesia were retrospectively reviewed in eight patients wit h arthroscopic evidence of posterosuperior glenoid impingement. RESULT S: All patients had shoulder pain; anterior instability was found in s ix patients. Other than bone marrow abnormalities, findings at MR imag ing were not reliable for the detection of posterosuperior glenoid imp ingement. MR arthrography was superior to routine MR imaging in all fo ur cases in which it was done; positioning the shoulder in abduction a nd external rotation was beneficial in three of four patients. CONCLUS ION: Impingement of the rotator cuff on the posterior superior glenoid labrum is a cause of posterior shoulder pain in athletes who throw. M R arthrography may allow detection of abnormalities associated with th is clinical entity.