OBJECTIVERotator cuff tears are a common shoulder problem and recently double-row repair techniques have shown superior biomechanical advantages when compared to single-row constructs in a properly selected patient. This study compared 2.8 mm and 4.5 mm anchors with respect to clinical and radiological outcome in two groups of patients. Of course, for the same number of 4.5 anchors used. Volume of Bone Replaced (VBR) will be far less if 2.8 anchors are used in equal number. But, in such surgeries, the ultimate objective was to restore the anatomic footprint and the number of anchors used varied accordingly. MATERIAL AND METHODS50 patients of rotator cuff tear (Size >3 cm) were treated with double-row method of repair arthroscopically. In 25 patients, 2.8 mm anchors were used and in rest 25 patients 4.5 mm anchors were used. Operated patients underwent CT scan of the shoulder during followup period. Using computer software (OsiriX), the cylindrical bone defects made for the anchors were measured by using the formula for volume of the cylinder. For every case, total Volume of Bone Replaced (VBR) was calculated. Since the plane of the anchor cannot always be sagittal or coronal, hence using MPR (Multiplanar reconstruction) tool in OsiriX, a plane was selected in which length of the anchor is the largest meaning that it is the plane parallel to true long axis of the anchor. Radius of the cylinder was calculated in a plane 90 degree to the previously defined plane. RESULTSComparing the two groups, we didn't find any significant difference in the clinical outcome. However, there was a significant difference in one radiological parameter-Volume of Bone Replaced (VBR). CONCLUSIONThere was no difference in clinical recovery in the two groups. However, Volume of Bone Replaced (VBR) was more in 4.5 mm anchor group when compared to 2.8 mm anchor group. This finding can be important to a surgeon when he is operating a re-tear in an already operated double-row patient since there will be a relatively more bone stock available for the surgeon to place additional anchors.