Table 1 Inclusion and exclusion criteria

Age > 65 years

3- or 4-part fractures

Fracture-dislocation

Fracture with comminution of tuberosities

Fracture with prior rotator cuff disease

Initial treatment with reverse prosthesis

Pathological fractures

Refractures

Open fractures

Plexus injury

Deltoid muscle disorders

Severe cognitive impairment according to SPMSQ (short portable mental status questionnaire)

Prior shoulder surgery