Glenohumeral instability: Validity of low-field MRI for diagnosis of labral tears

Abstract

Purpose To analyze the MRI findings of a series of patients with symptoms of glenohumeral instability and determine whether the diagnosis of a torn labrum can be confirmed by surgical exploration. Materials and methods Between January 2005 and January 2011, low-field MRI was performed in a total of 190 patients. Surgical treatment was administered to 127 patients, and only 62 of them were subjected to diagnostic arthroscopy. Results A total of 127 patients (66.8%) underwent surgery. The most frequent surgical procedure was Arthroscopic Bankart Repair (62 cases, 48.8%) with a total number of correct MRI-based labral tear diagnoses of 50 (overall predictive value: 83.3%). Discussion The analysis found nearly 80% correct labral tear diagnoses. The majority of errors were related to the diagnosis of SLAP lesions and attributable to several factors. Conclusion Low-field MRI is an appropriate method to diagnose labral tears, with sensitivity levels of 83.3%. Nevertheless, in order to correctly determine the type of lesion present it is advisable, though not indispensable, to carry out a direct MR arthrogram, except in the case of SLAP lesions, where diagnosis is virtually impossible without the addition of intra-articular contrast (unless patients with glenohumeral effusion).