Evaluation of bone stock and muscle quality with zero echo time sequence magnetic resonance imaging before arthroplasty in patients with shoulder osteoarthritis

One of the causes of shoulder osteoarthritis is Cuff Tear Arthropathy (CTA). The aim was to assess the morphological changes of the shoulder of CTA patients, evaluate inter- and intra-observer agreement using Zero Time Echo Magnetic Resonance Imaging (Zero Time Echo MRI [ZTE]), and investigate the relationship between these measurements and Rotator Cuff (RC) muscle cross-sectional areas, shoulder functional scores, and active joint movements. Inter-observer agreement was excellent for glenoid version and Critical Shoulder Angle (CSA) measurements, good for Humerus Subluxation Index (HSI), humeral head medialization, glenoid central and posterior bone loss, and best fit circle glenoid diameter measurements, while moderate agreement was found for glenoid anterior bone loss, glenoid vault depth, and best fit circle glenoid diameter loss rate (p<0.05). Intra-observer agreement was good and excellent for these measurements (p<0.05). For the Modified Walch classification, both inter-observer and intra-observer agreements were moderate (p<0.05). There was a moderate correlation between the cross-sectional area of the subscapularis muscle and active forward elevation, abduction, and internal rotation (p<0.05). Anterior bone loss had a negative moderate correlation with forward elevation and abduction, while humeral head medialization, central bone loss, and posterior bone loss had a low negative correlation (p<0.05). Glenoid retroversion had low to moderate correlations with HSI, humeral head medialization, and best fit circle diameter loss rate (p<0.05). The study concluded that ZTE MRI can be used to assess the osseous morphology of shoulders diagnosed with CTA. In CTA patients, the cross-sectional area of the subscapularis muscle was found to be one of the most important factors for pseudoparesis. Keywords: Shoulder, Rotator cuff, Magnetic resonance imaging, Zero echo time imaging, Rotator Cuff Tear Arthropathy