This clinical study aims at evaluating clinical, radiographic and patient-reported outcomes after total anatomic or reverse shoulder replacement using PRIMA humeral stem up to 24 months after surgery, in order to assess the short-term performance of the implant. Furthermore, the objective is also to collect short-term data on the survivorship of the implant and the incidence of complications.

Inclusion Criteria:

1. Age ≥ 18 years old;

2. Full skeletal maturity;

3. Life expectancy over 24 months;

4. Patient's joint anatomically and structurally suited to receive the selected implants and functional deltoid muscle;

5. Patient meets at least one of the following indications:

   For Anatomic configuration:

   • non-inflammatory degenerative joint disease (i.e., osteoarthritis);
   • inflammatory arthritis of the glenohumeral joint including rheumatoid arthritis;
   • avascular necrosis of the humeral head;
   • cuff tear arthropathy (CTA Heads only);

   For Reverse configuration:

   • rotator cuff tear arthropathy;
   • osteoarthritiswith rotator cuff tear;
   • rheumatoid arthritis with rotator cuff tear;
   • massive irreparable rotator cuff tear;

6. Patient is able to understand the conditions of the study, to comply with the prescribed rehabilitation as well as willing to perform all scheduled follow-up visits;

7. Patient has signed the Informed Consent form previously approved by the Ethics Committee before study activities.

Exclusion Criteria:

1. Patients who lack capacity to be able to provide informed consent to participate in the study.
2. Local or systemic general infection;
3. Septicaemia;
4. Persistent acute or chronic local or systemic osteomyelitis;
5. Confirmed neurologic lesion compromising shoulder joint function;
6. Deltoid muscle insufficiency;
7. Poor meta-epiphyseal bone stock compromising stability of the implant (severe fracture of the proximal humerus, meta-epiphyseal pseudoarthrosis, osteoporosis, osteomalacia, extended bone loss after previous prosthetic or non-prosthetic surgery);
8. Affected by malignant cancer with life expectancy less than 2 years or where cancer treatment might affect the normal postoperative course;
9. Serious muscular, neurological, or arterial vascular diseases compromising stability of the implant;
10. Proximal humerus fracture sequelae with inadequate bone stock;
11. Vascular or nerve diseases affecting the concerned limb;
12. Metabolic disorders which may impair fixation and stability of the implant;
13. Any concomitant disease that might affect the implanted prosthesis;
14. Metal hypersensitivity to implant materials (CoCrMo);
15. Patient with significant renal impairment;
16. Lower mobility issues that may affect the study evaluation;
17. Unwillingness or inability (due to physical or mental issues) to comply with rehabilitation and to return for follow-up visits and any psychiatric illness that would prevent comprehension of the details and nature of the study;
18. Women of childbearing potential who are pregnant, nursing, or planning to become pregnant;
19. Any clinically significant pathology based on the medical history that the Investigator feels may affect the study evaluation.

The eligible study population consists of 60 adult patients requiring a primary Total Shoulder Arthroplasty (TSA) or Reverse Shoulder Arthroplasty (RSA).

The decision to use PRIMA humeral stem has been taken by the Investigator prior to, and independently from, the decision to include the subject in the study.