Scandinavian Humeral Diaphyseal Fracture Trial

1. Fracture types 12A-C (OTA/AO classification) a. Includes minimal displaced extra-articular fracture extensions to the proximal humerus (less than a 1 cm or 45 degree angulation) 2. Treatment within 14 days from trauma 3. Age 18-64 years for SHAFT-Y and ≥65 years for SHAFT-E 4. Patients must understand the information given and be able to read and speak Danish, Swedish or Norwegian to complete the study paperwork All fracture extensions involving the distal humerus and displaced fracture extensions involving the proximal humerus will not be included. Isolated fractures to the proximal or the distal end of the humerus are not eligible for screening. The proximal and distal end segments of the humerus are defined by squares of which the sides are the widest length of the epiphysis/metaphysis in question on the anterior-posterior view. Exclusion criteria 1. Inability to give informed consent 2. Undisplaced shaft fracture (less than a cortex-wide displacement in all radiographic plane) 3. Vascular injury in ipsilateral arm 4. Polytrauma (defined as a trauma with one or more concurrent fractures to the upper extremities or other trauma absolute indications for surgical intervention) 5. Pathological fracture 6. Open fracture 7. BMI \> 40 8. Health conditions preventing either treatment