Large bone cysts associated with symptomatic rotator cuff tears may pose significant treatment problems. Bone loss associated with these cysts or with implant removal in cases of revision rotator cuff surgery may be so large that secure suture anchor fixation cannot be achieved with traditional techniques. This report describes how to arthroscopically bone graft these defects with a compaction technique that creates a densely packed bone bed into which suture anchors can be securely placed.