Inclusion Criteria:  both genders at least 18 years old of age undergoing a primary total shoulder arthroplasty with MIRAI® Prosthesis System (anatomic or reverse, stemless or stemmed). Signed informed consent  Exclusion Criteria:  Patients requiring a revision shoulder arthroplasty Persistent chronic or acute infections and all septic conditions Persistent osteomyelitis local or systemic Allergy or hypersensitivity to the substances contained in the materials of the implanted components Acute or chronic neurological and/or musculoskeletal impairment which compromises the shoulder joint function such as an axillary nerve injury affecting the deltoid muscle Inadequate bone structure which cannot guarantee stability to the prosthetic components Several vascular, nerve or muscular disorders, which compromise related extremities Marked osteoporosis, osteomalacia Hypotrophy of the periarticular soft tissues Dysmetabolic diseases such as, for example, kidney failure or systemic diseases Muscular insufficiency Active neoplastic or metastatic diseases Any other clinical or physical condition that can invalidate the surgery, the rehabilitation or the prosthesis stability Patient unwilling or unable to undergo the rehabilitation or to return to follow-up visits Women in pregnancy, childbearing potential or breastfeeding Involvement in other ongoing studies or clinical trial.