Management of combined bony and tendinous deficiency of the posterosuperior rotator cuff represents a challenge in young patients. In this case report, a 44-year-old woman that presented an osteonecrosis of the greater tuberosity had a pseudoparalytic shoulder. She beneficiated from a fresh-frozen Achilles tendon allograft with calcaneal bone, which was used to reconstruct the rotator cuff and the concomitant bony defect. At 12-month follow-up, the patient was pain free and had complete range of motion, normal strength, a SANE score of 95 and radiographically the allograft was healed. An Achilles tendon allograft may therefore be a viable surgical option to reconstruct a combine posterosuperior rotator cuff tear and greater tuberosity bone defect. Level of evidence IV.