Glenoid labral tears: prospective evaluation with MRI imaging, MR arthrography, and CT arthrography.

Abstract

We prospectively compared MR imaging, MR arthrography, and CT arthrography to determine the sensitivity of each technique in detecting glenoid labral tears and in determining whether the labrum is detached or degenerated. Thirty patients 19-39 years old (mean, 27 years old) who had either signs and symptoms of shoulder instability or shoulder pain of unexplained origin were referred for diagnostic imaging. Each patient underwent MR imaging, followed by MR arthrography after intraarticular injection of 25 ml of a dilute solution of gadopentetate dimeglumine. Twenty-eight of thirty patients underwent CT arthrography after intraarticular injection of air and radiographic contrast material. Each patient also underwent arthroscopy or open surgery. At surgery, labral tears were found in 28 patients; a detached fragment was found in 26 patients. The labrum was found to be degenerated in 18. A labral tear was detected on MR images in 26 (93%) of 28, on MR arthrograms in 27 (96%) of 28, and on CT arthrograms in 19 (73%) of 26. A detached labral fragment was detected on MR images in 12 (46%) of 26, on MR arthrograms in 25 (96%) of 26, and on CT arthrograms in 13 (52%) of 25. Labral degeneration was detected on MR images in two (11%) of 18, on MR arthrograms in 10 (56%) of 18, and on CT arthrograms in four (24%) of 17. MR arthrography was the best of the three imaging techniques for showing the inferior part of the glenoid labrum and inferior glenohumeral ligament. MR arthrography and MR imaging both showed labral tears with greater sensitivity than CT arthrography did. MR arthrography was the most sensitive of the three techniques for detecting a detached labral fragment and labral degeneration. Furthermore, MR arthrography afforded the best visualization of the inferior part of the labrum and the inferior glenohumeral ligament. MR imaging and MR arthrography also enabled direct visualization of rotator cuff disease and other unsuspected associated abnormalities.