Improved Visualization of the Middle Glenohumeral Ligament of the Shoulder with Internal Rotation in Axial MR Arthrography: A Comparative Positional Analysis

Objectives This study investigates the contribution of rotational maneuvers of the shoulder joint to the MR arthrographic visualization of the middle glenohumeral ligament (MGHL). Methods In this prospective study, 181 MR arthrography examinations referred to our clinic between May 2019 and January 2024 were evaluated for the MGHL. In addition to conventional MR arthrography sequences, axial MR arthrography images were obtained in internal rotation, external rotation, and neutral positions of the shoulder to demonstrate the MGHL. The arthrographic images obtained on a 3 T MR scanner were analyzed by a radiologist with 20 years of experience in musculoskeletal radiology. In each position, the subjective visibility of the MGHL was assessed in five categories: none, poor, fair, good, and excellent. The number of slices in which the MGHL could be visualized in each position was also recorded. The detectability of the MGHL in each position was then statistically compared. Results Of the 181 shoulder MR arthrograms evaluated in this study, 37 were excluded for various reasons. The mean age of the 144 patients included was 38.51 ± 13.83 years (range = 18–76); 96 were male and 48 were female. In 29 of the 144 MR arthrograms (21.1%), different anomalies of the MGHL were detected. Among 134 patients with MGHL, partial- or full-thickness ruptures were found in 36 (26.9%). In axial MR arthrography, the MGHL was best visualized in the internal rotation position. In addition, axial MR arthrography slices obtained in internal rotation allowed visualization of the MGHL in a greater number of sections. Conclusions The middle glenohumeral ligament is one of the important passive stabilizers of the shoulder joint. Optimal MR arthrographic imaging of pathologies and abnormalities of MGHL is critical for surgical planning. Our MR arthrographic series demonstrated that axial images obtained in internal rotation are more useful for visualizing the MGHL compared to neutral and external rotation. ADVANCES IN KNOWLEDGE The middle glenohumeral ligament (MGHL) is an important passive stabilizer of the shoulder joint. Accurate identification of this ligament is crucial because its variations can mimic certain pathologies. Particularly, axial MR arthrography images are highly effective for evaluating MGHL pathologies and variations. Axial MR arthrography images obtained in internal rotation allow clearer evaluation of the MGHL compared to neutral and external rotation images.