The initial treatment of complex proximal humerus fracture affects the outcome of revision with reverse shoulder arthroplasty.

<bold>Purpose: </bold>The purpose of the study is to report the results of reverse shoulder arthroplasty (RSA) after three types of initial treatment performed for complex proximal humeral fracture (PHF): conservative, reduction and internal fixation (RIF), or hemiarthroplasty.<bold>Methods: </bold>This is a retrospective study of 63 patients separated into three groups with a minimum follow-up of two years. Group I included 25 patients with an initial conservative fracture treatment, group II included 25 patients treated by RIF, and group III included 13 patients initially treated by hemiarthroplasty. Patients were assessed using the absolute Constant-Murley score, functional parameters, complications rate, and radiological follow-up.<bold>Results: </bold>One patient died and five were lost to follow-up. All functional outcomes improved significantly post-operatively for the three groups (p < 0.005). The mean Constant-Murley score increased from 13.7 to 54.1 (group I); 16.6 to 48.5 (group II); and 22.6 to 48.2 (group III) (p < 0.001). The gain of Constant-Murley and SST scores was better for group I (p = 0.049 and 0.028, respectively), while post-operative pain was better in group III (p = 0.033). The complication rate was 38% in group III, 30% in group II, and 14.3% in group I.<bold>Conclusions: </bold>Reverse shoulder arthroplasty represents a good surgical option in complex proximal humeral fracture sequelae. Whatever the initial treatment, function and motion of the shoulder are improved. The final result is better if the initial treatment was conservative. The group initially treated with hemiarthroplasty had the most complications. [ABSTRACT FROM AUTHOR]