Reverse shoulder arthroplasty versus hemiarthroplasty versus non-surgical treatment for older adults with acute 3- or 4-part fractures of the proximal humerus: study protocol for a randomised controlled trial (PROFHER-2: PROximal Fracture of Humerus Evaluation by Randomisation – Trial Number 2)

BACKGROUND: Proximal humerus fractures (PHF) are common and painful injuries, with the majority resulting from falls from a standing height. As with other fragility fractures, its age-specific incidence is increasing. Surgical treatment with hemiarthroplasty (HA) and reverse shoulder arthroplasty (RSA) have been increasingly used for displaced 3- and 4-part fractures despite a lack of good quality evidence as to whether one type of arthroplasty is superior to the other, and whether surgery is better than non-surgical management. The PROFHER-2 trial has been designed as a pragmatic, multicentre randomised trial to compare the clinical and cost-effectiveness of RSA vs HA vs Non-Surgical (NS) treatment in patients with 3- and 4-part PHF. METHODS: Adults over 65 years of age presenting with acute radiographically confirmed 3- or 4-part fractures, with or without associated glenohumeral joint dislocation, who consent for trial participation will be recruited from around 40 National Health Service (NHS) Hospitals in the UK. Patients with polytrauma, open fractures, presence of axillary nerve palsy, pathological (other than osteoporotic) fractures, and those who are unable to adhere to trial procedures will be excluded. We will aim to recruit 380 participants (152 RSA, 152 HA, 76 NS) using 2:2:1 (HA:RSA:NS) randomisation for 3- or 4-part fractures without joint dislocation, and 1:1 (HA:RSA) randomisation for 3- or 4-part fracture dislocations. The primary outcome is the Oxford Shoulder Score at 24 months. Secondary outcomes include quality of life (EQ-5D-5L), pain, range of shoulder motion, fracture healing and implant position on X-rays, further procedures, and complications. Independent Trial Steering Committee and Data Monitoring Committee will oversee the trial conduct, including the reporting of adverse events and harms. DISCUSSION: The PROFHER-2 trial is designed to provide a robust answer to guide the treatment of patients aged 65 years or over who sustain 3- and 4-part proximal humeral fractures. The pragmatic design and recruitment from around 40 UK NHS hospitals will ensure immediate applicability and generalisability of the trial findings. The full trial results will be made available in a relevant open-access peer-reviewed journal. TRIAL REGISTRATION: ISRCTN76296703. Prospectively registered on 5th April 2018 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-023-07259-3.