Inclusion Criteria:  Patient is 18-75 years of age, inclusive. Patient is skeletally mature. Patient is capable of understanding the doctor's explanations, following his instructions and is able to participate in the follow-up program. Patient must have signed EC-approved informed consent. Patient requires a primary reversed total shoulder arthroplasty or a conversion from anatomical to reversed to relieve pain and restore the joint function. Patient has adequate quality and quantity of bone stock to support the prosthesis.  Patient meets at least one of the following indications:  Advanced wear and tear of the shoulder joint resulting from degenerative, posttraumatic or rheumatoid arthritis Conditions consequent to earlier operations Omarthrosis or Osteoarthritis Rheumatoid arthritis Total joint reconstruction following trauma Patient has significant shoulder disability due to gross and irreparable rotator cuff deficiency. A functional deltoid muscle is necessary to use the device. Patient underwent reverse total shoulder reconstruction with the Anaverse Glenoid System before the date of site initiation. Patient has demographic, pre-operative evaluation, operative report and device information available.  Specific inclusion criteria for Conversion from Anatomical to Reversed Configuration:  Surgery was performed with the Anaverse Glenoid System in a previously available anatomical configuration. Irreparable rotator cuff with superior migration of the humeral head, leading to a reduction in sub-acromial space. Superior tilt of the Anaverse Glenoid Baseplate not exceeding 15° compared to scapular axis. No evidence of mechanical or fixation failure of the Baseplate, TM Pegs or DPSC Screws, obtained pre- or intra-operatively, which would compromise the success of the conversion surgery.  Exclusion criteria:  Patient is unwilling or unable to give consent or to comply with the follow-up program. Patient has any condition which would in the judgment of the Investigator place the patient at undue risk or interfere with the study. Patient is known to be pregnant or breastfeeding. Patient is a vulnerable subject (prisoner, mentally incompetent or unable to understand what participation to the study entails, a known alcohol or drug abuser, anticipated to be non-compliant). Patient has any physical conditions that would impair adequate implant support and/or prevent the use of an appropriately sized implant. Patient has any sign of infection (affecting the shoulder joint or in its proximity). Patient has glenoid presenting with large defects due to erosion, which would lead to insufficient bony support or malalignment of the devices. Patient is skeletally immature. Patient has any sign of neuromuscular compromise (excluding rotator cuff tear). Patient has vascular deficiency in the affected limb in sufficient degree to endanger the success of the intervention. Patient has absence of musculo-ligamentous supporting structures. Patient suffers from joint neuropathy or other conditions that may lead to inadequate skeletal fixation. Patient has significant injury to the upper brachial plexus. Patient has non-functional deltoid muscle.  Specific exclusion criteria for Conversion from Anatomical to Reversed Configuration:  Unstable fixation of Baseplate after removal of PE Liner. Superior tilt of Baseplate exceeding 15° compared to scapular axis Superior malposition of the Baseplate which would prevent correct assembly of the Glenosphere. Evidence of mechanical or fixation failure of the Baseplate, TM Pegs or DPSC Screws, obtained pre- or intra-operatively, which would compromise the success of the conversion surgery.