Current imaging methods are inadequate to determine the extent to which the repaired rotator cuff tendon has "failed with continuity". The investigators have developed an imaging technique to detect this phenomenon. Specifically, radio-opaque markers are sutured onto the repaired tendon and impacted into the nearby arm bone. The distance between the tendon and bone markers is measured from CT scans taken within 2 weeks of surgery, and compared to the distance between the markers at 3, 6, 12 and 24 months. If the tendon retracts away from the bone during healing, the distance between the tendon and bone markers will increase over time. Healing of the tendon will also be monitored in the traditional manner by MRI scans at the same time points. The investigators will investigate the relationship between tendon retraction, MR imaging and clinical outcomes including shoulder strength and patient satisfaction.