Accuracy of Magnetic Resonance Arthrography in the Detection and Classification of Chronic Anteroinferior Labrum Lesions

Abstract

INTRODUCTION: Bankart, and Bankart variant labrum lesions such as Perthes lesion and anterior labrum periosteal sleeve avulsion are different types of surgically treatable anterioinferior labral lesions contributing to shoulder instability. Successful outcome following arthroscopic surgery requires accurate lesion diagnosis, pre operative planning and deployment of accordant surgical technique. The purpose of our study was to retrospectively evaluate the accuracy of Magnetic Resonance Arthrography not only in the detection but also the classification of chronic antero-inferior labrum injuries by using arthroscopy as the reference standard. STUDY

DESIGN & METHODS:This study included 80 consecutive patients, 12 female with mean age of 28 year (range 17-46) presenting with recurrent shoulder instability who underwent Magnetic Resonance Arthrography in neutral and abduction external rotation positions prior to arthroscopic stabilisation. The findings of a single dedicated musculoskeletal radiologist were compared with the arthroscopic findings of a single experienced shoulder surgeon.

RESULTS: Arthroscopic findings revealed 40 Bankart, 18 anterior labrum periosteal sleeve avulsion and 15 Perthes anteroinferior labrum lesions. Magnetic Resonance Arthrography detected 95.8% of overall labrum lesions with a sensitivity of 94% (0.86 to 0.98 ) and specificity 85.7% (0.46 to 0.99 ) and correctly classified 90% of labrum lesions with an accuracy of 93.8% (0.86-0.97) for Bankart lesions, 95% (0.88-0.98) for anterior labrum periosteal sleeve avulsion lesions and 95.5% (0.91-0.99) for Perthes lesions.

CONCLUSION: Our study demonstrates that Magnetic Resonance Arthrography in neutral and abduction and external rotation position can achieve high levels of accuracy in detecting and correctly classifying chronic anteroinferior labrum lesions. It emphasises its value in alerting the surgeon to the presence and the type of labrum lesion. This allows forward-planning the surgical technique to be employed for intra-operative detection, correct dissection and optimal fixation.