Treatment in acromion fracture after reverse shoulder prosthesis

Background: Reverse shoulder arthroplasty (RSA) is an established procedure. The rare complication of an acromion fracture and its treatment is seldom discussed. Objectives: The aim of this study was (1) to show the incidence of acromion fractures after RSA and (2) compare the conservative or surgical treatment options and their results. Materials and methods: A retrospective study was conducted on 583 reverse shoulder arthroplasties between 2008 and 2014 in which 12 fractures were identified at postoperative follow-up. The first 6 patients with these fractures were treated operatively; the later 6 patients were treated conservatively. An analysis was performed on the variables functional results, quality of life (Constant score, pain, satisfaction), and radiological results comparing the two treatment options. Results: The fracture incidence was 2.05% with a mean age of 75.9 years. The mean time interval between index operation and fracture diagnosis was 11.4 months. The last Constant score (CS) before fracture was 74.2 points. Posttreatment CS was 55.4 points in the operated group and 55.3 points in the conservative group. Within the subcategories the conservative group had larger benefit in pain, the operated group gained more points in strength. There were no instability cases and no revision surgery was required. Four of 6 conservatively treated fractures and 5 of 6 surgically treated patients were consolidated within one year. Conclusions: Acromion fracture after RSA is a rare complication. Despite its presence, the functional outcomes and quality of life of these patients are higher than preoperatively; however, they are lower than that obtained in patients with RSA without this complication. © 2016, Springer Medizin Verlag Berlin.