Is MRA an unnecessary expense in the management of a clinically unstable shoulder?

Abstract

Background and purposeIn detection of glenoid labrum pathology, MR arthrography (MRA) has shown sensitivities of 88-100% and specificities of 89-93%. However, our practice suggested that there may be a higher frequency of falsely negative reports. We assessed the accuracy of this costly modality in practice.Patients and methodsWe retrospectively reviewed MRA reports of 90 consecutive patients with clinical shoulder instability who had undergone shoulder arthroscopy. All had a history of traumatic anterior shoulder dislocation and had positive anterior apprehension tests. All underwent arthroscopy and stabilization during the same procedure. We compared the findings, using arthroscopic findings as the gold standard in the identification of glenoid labrum pathology.Results83 of the 90 patients had glenoid labrum tears at arthroscopy. Only 54 were correctly identified at MRA. All normal glenoid labra were identified at MRA. This gave a sensitivity of 65% and a specificity of 100% in identification of all types of glenoid labrum tear. 74 patients had anterior glenoid labral tears that were detected at an even lower rate of sensitivity (58%).InterpretationThe sensitivity of MRA in this series was substantially lower than previously published, suggesting that MRA may not be as reliable a diagnostic imaging modality in glenohumeral instability as previously thought. Our findings highlight the importance of an accurate history and clinical examination in the management of glenohumeral instability. The need for MRA may not be as high as is currently believed.

A comparison of magnetic resonance arthrography and arthroscopic findings in the assessment of anterior shoulder dislocations

“…This sensitivity of Bankart lesions is within the range previously reported in the literature (0.65-0.95) [21][22][23][24]. The 1.0 sensitivity of MRA for Hill-Sachs lesions was similar to that presented in the literature (0.96-1.0) [22,25]; however, the 0.8 specificity is lower than that previously reported [22,25].…”

Diagnostic performance of magnetic resonance arthrography of the shoulder in the evaluation of anteroinferior labrum abnormalities: a prospective study

“…Therefore, accurate identification of labral and glenohumeral ligament tears has become a significant diagnostic goal [20, 21]. The purpose of our study was to assess the diagnostic performance of MR arthrography in the diagnosis of anteroinferior labrum lesions, using arthroscopy as the reference standard and to classify these lesions.…”

Is clinical evaluation alone sufficient for the diagnosis of a Bankart lesion without the use of magnetic resonance imaging?

“…MRI may also be augmented with the use of contrast, as in magnetic resonance arthrogram (MRA). Studies have reported good sensitivities and specificities with these two modalities (6)(7)(8). Some studies have gone further to show the superiority of MRA over MRI in the diagnosis of labral tears (5,8,9).…”