Unclassified MR arthrography pattern evaluation in patients with episodes of recurrent antero-inferior shoulder dislocation

Purpose: To evaluate prospectively the incidence of unclassifiable MR arthrography patterns of glenoid anterior–inferior labrum lesions, in patients with at least two episodes of recurrent antero-inferior shoulder dislocation. Materials and methods: The MR shoulder Arthrography images of 36 patients, with at least two episodes of recurrent antero-inferior dislocation, were prospectively evaluated, during a period between November 2015 and Mai 2016. All patients were contacted after 6 months of the MR arthrography to evaluate their course of treatment. The MR arthrography images were analyzed by two radiologists, respectively with 5 and 15 years of experience in musculoskeletal radiology. Results: 36 cases of unclassifiable MR arthrography pattern of the anterior–inferior glenoid labrum were evaluated: in 13 out 36 cases (36.1%), the glenoid labrum has been described as “oedematous and swollen”; in 19 out 36 cases (52.8%), it has been described as “smooth” (not hypoplastic); in 4 out 36 cases (11.1%), it has been described as degenerated. Conclusion: The unclassifiable MR arthrography patterns of fibrocartilage glenoid lesions after episodes of recurrent antero-inferior dislocation are commons. The unclassifiable MR arthrography patterns require a careful consideration, in order to improve the diagnostic and therapeutic multidisciplinary approach.