Arthroplasty in three- or four-part proximal humerus fracture: hemi or reverse?

Proximal humerus fractures account for 10% of all fractures and in the elderly population it is the 3rd most common fracture. The treatment of 3- or 4-part fractures, as described by Neer, consists of conservative treatment, plate fixation, percutaneus fixation or arthroplasty. However, the literature does not support valid decision making among surgical procedures, or even between operative and non-operative treatment. Especially in displaced three and four part proximal humerus fractures the ideal treatment sequel is still undefined. Regardless of the primary treatment, operative or non-operative, the complex proximal humerus fractures result in a functional impairment of the shoulder and arm resulting in a substantial negative effect upon the patients’ quality of life.



Operative management of these fractures with osteosynthesis often provides good initial fracture reduction, but with a risk of secondary loosening in osteoporotic bone or humeral head osteonecrosis, leading to high complication and re-intervention rates. A reliable alternative is shoulder arthroplasty, with hemi-arthroplasty as the reference treatment, which is a safe surgical procedure with relatively low complication rates. An advantage in quality of life in favor of hemiarthroplasty compared to non-operative treatment in elderly patients with a displaced 4-part fracture of the proximal humerus has been demonstrated. Although good outcomes regarding pain are described, the outcomes regarding restoration of function are still poorly predictable. The main factor leading to a poor functional outcome is the lack of healing of the tubercles after shoulder arthroplasty in fracture patients.



Reversed shoulder arthroplasty, which is less dependent on the function of the rotator cuff, is a new alternative for hemi-arthroplasty in fracture patients. It is a common procedure in other shoulder disorders as, osteoarthritis and cuff tear arthropathy, with good functional results. Without the necessity of an adequate cuff and vascularised tubercula reversed shoulder arthroplasty can possibly provide a better functional and a better predictable outcome with the same pain reduction. Up until now the reported outcomes of reversed shoulder prosthesis in fracture patients seems promising in single series. However the overall are not generally better than those reported for a primary hemi arthroplasty and randomized trials are lacking.



Therefore, we designed a randomized controlled trial to determine whether reversed shoulder arthroplasty may lead to a better functional outcome than hemi-arthoplasty among patients with a three or four part proximal humeral fracture. This paper reports the study design of the Proshere-trial (arhtoplasty in PROximal humerus fractureS; HEmi or REverse?)

Our hypothesis is that reverse arthroplasty has a better functional outcome and patient satisfaction than hemi-arthoplasty in patients with a three or four part proximal humerus fracture.

Follow-up on both groups will take place at 6 weeks, 3, 6 and 12 months after commencement of treatment.

1. Aequalis fracture prosthesis;

2. Aequalis reverse fracture prosthesis.