Retrospective Encore Reverse Shoulder Prosthesis Study

Inclusion Criteria: * The RSP is indicated for use in patients with a grossly rotator cuff deficient shoulder joint with severe arthropathy or a previously failed joint replacement with a grossly rotator cuff deficient shoulder joint. * The patient's joint must be anatomically and structurally suited to receive the selected implant(s), and a functional deltoid muscle is necessary to use the device. * The glenoid baseplate is intended for Cementless application with the addition of screws for fixation. The humeral stem is intended for cemented use only. Exclusion Criteria: * Infection or sepsis * Insufficient bone quality which may affect the stability of the implant, as determined by the physician * Muscular, neurological, or vascular deficiencies, which compromise the affected extremity * Alcoholism or other addictions * Materials (metals, etc) sensitivity * Loss of ligamentous structures * High levels of physical activity * Non-functional deltoid muscle