Locked Plate Fixation of Proximal Humerus Fractures in Non-elderly Adults: Analysis of Short-Term Outcomes.

Introduction Proximal humerus fractures (PHFs) represent the third most common adult fracture, increasingly affecting women and middle-aged individuals. While older patients typically sustain PHFs via low-energy trauma, younger populations more frequently incur these injuries through high-energy mechanisms. Surgical decision-making is influenced by patient-specific factors, with open reduction and internal fixation (ORIF) using locking plates considered a reliable technique for select cases. Despite demonstrated utility, limited data exist regarding functional outcomes of locking plate fixation in non-elderly adults. Methods This was a retrospective study of 17 non-elderly patients between the ages of 18 and 65 who underwent ORIF with locking plates for PHFs at a single Level 1 trauma center between January 2014 and December 2024. Patient demographics, fracture classification, comorbidities, and radiographic features were documented. Validated functional outcome measures were collected via phone following informed consent. Subgroup analysis evaluated differences by sex, smoking status, and fracture type. Results Revision surgery occurred in two patients, and most demonstrated satisfactory shoulder motion at final follow‑up, aside from one four‑part fracture case with persistent rotational limitation. Functional outcomes and range of motion did not reveal clear differences by sex, smoking status, or fracture classification, though the small cohort limits definitive conclusions. Conclusion Although constrained by a small cohort and short‑term follow‑up, our results indicate that ORIF with locking plates may provide acceptable early outcomes for two‑ and three‑part fractures in non‑elderly patients. However, given that only two individuals had four‑part fractures and one continued to exhibit rotational deficits, the data are insufficient to support any conclusions about the effectiveness of ORIF for four‑part injuries. Future studies with greater power are required to better define the role of fracture complexity and patient‑level variables in short- and long‑term recovery.