Changes in the Articular Cartilage Thickness in Patients with Symptomatic Rotator Cuff Tears: A Prospective Study with a Mean 5-Year Follow-Up

<b>Objectives:</b> The purpose of this study was to prospectively investigate the progression of cartilage thinning in patients with symptomatic rotator cuff tears using MRI. <b>Methods:</b> Two hundred twenty-five consecutive patients with symptomatic rotator cuff tears visited our institute between 2009 and 2019. Of these, 28 shoulders of 27 patients (mean age, 65 years) who underwent at least two magnetic resonance imaging (MRI) examinations were prospectively enrolled. They all received conservative treatment. The mean follow-up was 67 months. Changes in cartilage thickness and the combined cartilage and subchondral bone thickness at the initial and final MRI were measured using a RadiAnt DICOM-viewer (Medixant, Poznan, Poland). The cartilage thickness of the humeral head was measured in the oblique coronal and sagittal images. The glenoid cartilage was measured in the axial and oblique coronal images. <b>Results:</b> At an average period of 5 years, 12 of 28 shoulders (42%) showed more than a 30% decrease in cartilage thickness in the humeral head. The glenoid showed cartilage thinning in only one shoulder (4%). In the humeral head, progressive cartilage thinning was seen mainly in the anterior and posterior parts of the humeral head in the sagittal plane. In the glenoid, progressive cartilage thinning was seen on the entire surface except the posterior area. There was no significant difference in cartilage thickness between the first and final follow-ups for both the humeral head and the glenoid. <b>Conclusions:</b> A total of 12 of 28 shoulders (42%) showed more than a 30% decrease in cartilage thickness in the humeral head, which was mainly observed in the anterior and posterior areas of the humeral head.