The investigators will conduct a randomised, multi-centre, clinical trial including patients from ten national shoulder units within a two year period. Patients will be randomised to non-surgical treatment, hemiarthroplasty or angle-stable plate osteosynthesis. All patients will receive a standardised three-month rehabilitation program of supervised physiotherapy. Patients will be followed at least one year and will be assessed blindly according to a standardised evaluation protocol including Constant Disability Scale, Oxford Shoulder Score, and Short Form-36.