Plate fixation of the proximal humerus: an international multicentre comparative study of postoperative complications

The primary aim was to evaluate the number of complications following locking plate fixation of proximal humeral fractures in country X and in country Y. The secondary aim was to identify risk factors for complications. Multicentre retrospective case series of 282 consecutive patients with proximal humeral fractures, treated with a locking plate between 2010 and 2014. Setting: two level 1 trauma centres in country X and one in country Y. Data pertaining to demographics, postoperative complications and re-operations were collected. Fractures were classified according to the AO and Hertel classifications and experienced surgeons assessed the quality of reduction and plate fixation on the postoperative X-rays. Outcomes of the two different countries were compared and logistic regression analysis was performed to analyse the relationship between risk factors and complications. During a median follow-up of 370 days, 196 complications were encountered in 127 patients (45%). The most frequent complications were: screw perforation in the glenohumeral joint (23%), persistent shoulder complaints (16%), avascular necrosis of the humeral head (10%) and secondary fracture displacement (5%). In 80 patients (28%), 132 re-operations were performed. The patients operated in country X had significantly more complications compared with the patients operated in country Y. For implant-related complications, advanced age, non-anatomic reduction of the greater tuberosity, and country of operation were risk factors. The use of locking plates for proximal humeral fractures was associated with a high number of complications in both countries; the patients operated in country Y, however, had better results compared with the patients operated in country X. I