30 patients with two-tendon chronic retracted rotator cuff tears were randomized to receive an acellular dermal allograft rotator cuff reconstruction or an arthroscopic maximal rotator cuff repair for the treatment of large, chronic tears of the rotator cuff. Outcomes of interest included re-tear rate, the incidence of rotator cuff arthropathy progression, change in acromio-humeral distance (AHD), patient reported outcomes (WORC, DASH, MARX scores). and range of motion. Follow up was performed at a mean of 15 months post-operation. Both groups reported significant improvements in patient reported outcomes. Re-tear rate, change in AHD, incidence of rotator cuff arthropathy progression and range of motion were all significantly in favour of the reconstruction group compared to the repair group.