41 patients with a full-thickness rotator cuff tear were randomized to either surgical repair or conservative treatment. Patients were assessed at 1 year postoperatively for muscle atrophy and fatty infiltration on MRI. Of the 19 patients allocated to repair, five patients had intact repairs at 1 year, while the remaining 14 had either a retear or failed repair. Irrespectively, change in tear size, the degree of muscle atrophy, and fatty infiltration on MRI after 1 year was reported to no significantly differ between patients managed with a repair and patients managed conservatively.