Tornier Perform™ Reversed Monopost Study

Inclusion Criteria: * 18 years or older at the time of the informed consent. * Informed and willing to sign an informed consent form (ICF) approved by Institutional Review Board (IRB) or Ethics Committee (EC). * Willing and able to comply with the requirements of the study protocol * Considered a candidate or having received shoulder arthroplasty with the device, having a functional deltoid muscle and with massive and non-repairable rotator cuff tear with pain disabled by: * Rheumatoid arthritis * Non-inflammatory degenerative joint disease (i.e. osteoarthritis and avascular necrosis) * Correction of functional deformity * Fracture of the Humeral Head * Traumatic arthritis * Revision of the devices if sufficient bone stock remains * Enrollment occurred up to 1 year after date of surgery provided that mandatory data are accessible: including ASES, Constant, and Active ROM. Exclusion Criteria: * Contraindications or hypersensitivity to the use of the Tornier Perform™ Reversed MonoPost System or their components (e.g., metal sensitivity). * Participation in the treatment period of another clinical trial during the clinical investigation. * Any subject that meets the definition of a Vulnerable Subject per ISO 14155 Section 3.44. Examples include any subject "with lack of or loss of autonomy due to immaturity or through mental disability, persons in nursing homes, children, impoverished