Poly vs Hybrid Glenoid in Stemless aTSA

Inclusion criteria

• In order to be eligible to participate in this study, a subject must meet all of the following criteria:
• Both genders;
• Age 18 years old;
• Life expectancy over 5 years;
• Patient has symptomatic shoulder osteoarthritis for more than 1 year and is submitted to previous conservative non-surgical treatments;
• Patient is requiring primary unilateral or staged bilateral anatomic arthroplasty based on physical examination, medical history and X ray examination. (In cases where bilateral aTSA's are indicated, the patient will be included for the second aTSA again when the patient meets the inclusion criteria);
• Good bone quality evaluated by the investigator on the basis of a risk factors analysis and the intraoperative estimation;
• A diagnosis in the target shoulder of osteoarthritis; according to the classification of Walch, the glenoid should be a type A1, A2 or B1. Retroversion should not exceed 15 degrees.
• Patient is willing and able to complete scheduled follow-up evaluations as described in the Informed Consent;
• Patient has participated in the Informed Consent process and has signed the Informed Consent form previously approved by the Ethics Committee.

Exclusion criteria

• Patient requiring revision shoulder arthroplasty;
• Osteoporosis with a history of non-traumatic fractures;
• Steroid injections within the previous 6 months;
• Contralateral shoulder replacement within the previous 3 months;
• Meta-epiphyseal bony defect (including large cysts);
• Significant proven or suspicious infection of the target shoulder or any serious infectious disease
• Significant neurological or musculoskeletal disorders that may compromise functional recovery;
• Known or suspicious hypersensitivity to the metal or other materials of the implant;
• Unwillingness or inability (i.e. alcoholism, infirmity) 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;
• Any systemic disease which may affect outcome.
• Active or metastatic neoplastic disease
• Chemotherapy and/or radiotherapy within the last 6 months
• Previous organ transplant
• Participation in any clinical research study that may interfere with this study
• A current or prior DSM-5 diagnosis of schizophrenia, delusional disorder, schizoaffective disorder, psychotic disorder or bipolar disorder.
• Current substance use disorder (excluding nicotine/tabacco use disorder) or moderate or severe alcohol use disorder.
• Imminent suicide risk.
• Any other psychiatric condition that renders the individual unsuitable for the study according to the study physicians judgment