Inclusion Criteria:

• Male or female subjects, aged less than 85 years inclusive.
• Subjects who have cuff tear arthropathy, osteoarthritis with cuff deficiency, rheumatoid arthritis, post traumatic injury, or a need for revision surgery of a failed anatomic prosthesis in the left or right shoulder, which requires (total) shoulder arthroplasty.
• Subjects with radiographic evidence of sufficient bone stock to seat and support the Delta XtendÔ Reverse Total Shoulder System.
• Subjects who in the opinion of the Clinical Investigator are considered suitable for treatment with the Delta Xtend Reverse Total Shoulder System.
• Patients with a life expectancy of greater than 12 months.
• Subjects who are able to give voluntary, written informed consent to participate in this clinical investigation and from whom consent has been obtained.
• Subjects who, in the opinion of the Clinical Investigator, are able to understand this clinical investigation, co-operate with the investigational procedures and are willing to return to the hospital for all the required post-operative follow-ups.

Exclusion Criteria:

• Male and female subjects aged 86 years or older.
• Subjects with complete deltoid muscle palsy in the target joint as determined by clinical evaluation.
• Subjects with active local or systemic infection or with a history of general or local infections in the target joint over the past 12 months.
• Subjects with severe deformities, or tumours, that would impair fixation or proper positioning of the implant.
• Subjects with no significant muscle, nerve or vascular disease.
• Subjects with a pathology that, in the opinion of the Clinical Investigator, will adversely affect healing.
• Known allergic reactions to implant materials (e.g. bone cement, metal, polyethylene) implant corrosion or implant wear debris.
• Subjects with a known history of poor compliance to medical treatment.
• Subjects who, in the opinion of the Clinical Investigator, have an existing condition that would compromise their participation and follow-up in this clinical investigation.
• Women who are pregnant.
• Subjects who are known drug or alcohol abusers or with psychological disorders that could affect follow-up care or treatment outcomes.
• Subjects who have participated in a clinical investigation with an investigational product in the last month.
• Subjects who are currently involved in any injury litigation claims.