To investigate the assumption that reversed shoulder prosthetic replacement will give a better functional outcome compared to open reduction and internal fixation with an angular stable plate in displaced proximal humeral fractures. Short name: The DelPhi trial.

Reversed total shoulder artroplasty (RTSA) equals Delta Xtend reversed total shoulder prosthesis.

Angular stable plate means Proximal humerus plate (Philos)

Inclusion Criteria:

Patient admitted in hospital with a displaced three- or four part proximal humerus fracture of OTA / AO group 11-B2 or 11-C2 (displaced fracture of extra-articular or articular, bifocal type). The subgroups -.1, -.2 and -.3 will be included for both B2 and C2 groups, provided severe displacement: This is defined as a mal-position of at least 45º of angular deviation in valgus or 30º in varus in true frontal projection, regardless of whether the fracture is impacted or not, or less than 50% contact between humeral head and the metaphyseal part of the shaft. The greater or lesser tubercle displaced at least 10 mm.

Exclusion Criteria:

Patient younger than 65 years or older than 85 years, previous history of injury or illness of the injured shoulder, injuries of other parts of the humerus or the contra-lateral upper extremity, alcohol- or drug abuse, dementia, neurological diseases, or severe cardiovascular or lung diseases that would contraindicate surgery. Patients have to understand the Norwegian language and be compliant to rehabilitation and follow-ups.