Retrospective study comparing first and new-generation proximal humerus locking plates in 152 proximal humerus fracture cases

ABSTRACT Objectives The aim of this study was to compare proximal humerus fracture outcomes in terms of stability and quality of reduction when using the first-generation plate and a new-generation plate. Material and method This retrospective consecutive cohort study included patients with proximal humerus fractures operated between 2007 and 2023 in a level 1 adult trauma center. The inclusion criteria were fracture of the proximal third of the humerus with preoperative, postoperative and follow-up radiographs, operated with either one of the plates studied. Arthroplasty, nailing and conservative management were excluded. Demographic data were collected from the trauma database and radiological measurements were performed by an independent evaluator. The neck-saft angle, calcar displacement, greater tubercle height, humeral head offset, and plate position were measured. Results One-hundred-fifty-two patients met the inclusion criteria. Sixty-two percent were women (n=95), with a mean of 59.5 years and average follow-up time of 24 months. There were 123 first-generation plates and 29 new-generation plates. There was no difference in age, smoking, follow-up time, or initial reduction quality between groups. At the last follow-up, there was a significant difference in plate height. This is influenced by the varus collapse (plate will appear "higher"). The new-generation plate was lower (distance between the plate and the greater tubercle) than the first-generation plate, with 17.6 ±5.2 mm vs 13.7 ±5.6 mm at the early post-operative x-ray, and 15.2 ±4.3 mm vs 11.4 ±4.7 mm at the last radiograph (p<0.001 in both cases). There was more secondary displacement of the neck shaft angle in the first-generation group (9.1° vs. 4.5° (p= 0.018)). There were more men in the group with the new plate design, but no significant difference was found between sexes in the measured variables, including the measured displacement parameters (p > 0.192). Conclusions These medium-term outcomes showed an acceptable plate position with the new-generation plate and less secondary humeral head displacement.