Magnetic resonance arthrography accuracy in the detection of labral tears in young patients with chronic unstable shoulder: correlation with arthroscopy

Abstract

The aim of this study is to determine the diagnostic performance of Magnetic Resonance Arthrography(MRA) in evaluating lesions of the glenoid labrum, in young active patients with chronic unstableshoulder, compared to shoulder arthroscopy. We retrospectively considered 65 MRA examinations,performed between December 2011 and January 2018. Among them, thirty-five patients (31 men, 4women; mean age, 27.3 years; range, 16-53 years; 4 patients with a previous arthroscopy of the sameshoulder) underwent shoulder arthroscopy after MRA. Arthroscopic reports were collected andanalyzed for the correlation with MRA results. The inclusion criteria were: a) clinical symptoms ofchronic shoulder instability with at least 2 episodes and less than 5 episodes of shoulder dislocation; b)arthroscopy performed by surgeons in our institution; c) non-professional sportsmen, that is occasionalor amateur sport practice. MRA examinations, carried out with a 1.5 T superconductive magnet, wereevaluated by two radiologists. The authors observed complete agreement between MRA evaluation andarthroscopic findings in 31 patients, and disagreement in 4 patients. Sensitivity was 93%, specificity71%, positive predictive value 93%, negative predictive value 71% and the diagnostic accuracy for allglenoid lesions 88%. In patients with chronic shoulder instability, MRA confirmed its high sensitivityand positive predictive value for the diagnosis of labral lesions, providing useful information on the sizeand extent of the tears. The lower value of specificity and negative predictive value were probably dueto the small number of patients who underwent arthroscopy after an MRA negative for glenoid injuries.