The purpose of this study is to evaluate the survivorship and efficacy of the Encore Reverse Shoulder Prosthesis in a group of no more than 50 subjects for whom data collection has already begun.

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

Individuals who meet the indications for use of the RSP device AND who meet the inclusion/exclusion criteria

The first subject was treated in 2005 and the final subject came in for their final follow-up visit in 2008. The study ran for 3 years but adverse events were only collected on subjects from their day of surgery through their one year follow-up visit.