Retrospective analysis of open reduction and locking plate fixation in three and four part proximal humeral fractures with efficacy and complications.

Three- and four-part proximal humeral fractures are common in young and elderly populations. Open reduction and fixation with a locking plate is a commonly used surgical technique; however, it is associated with a high incidence of complications. This study aimed to retrospectively evaluate the clinical effectiveness of open reduction and fixation with a locking plate for treating three- and four-part proximal humeral fractures and to analyze potential risk factors for complications. The clinical data of 126 patients with three-part (57 cases) or four-part (69 cases) fractures of the proximal humerus who presented to our center between January 2014 and January 2024 were selected. At the final follow-up (i.e., 12 months post-operation), the postoperative clinical efficacy was evaluated by comparing the Constant-Murley score, Disabilities of the Arm, Shoulder and Hand (DASH) score, Visual Analog Scale (VAS) score, and range of motion (ROM) of the shoulder joint between the affected side and the unaffected side. Additionally, the relationships between the clinical efficacy and the loss angle of the humeral neck-shaft angle (NSA) as well as the loss humeral head height (HHH) were analyzed. In addition, we also analyzed the most common complications among the patients and the associated risk factors. In the evaluation of clinical efficacy, there were no significant differences in the ROM of the shoulder joint and clinical scores between the unaffected side and the affected side of the patients at 12 months postoperatively (P > 0.05). The analysis of the relationship between the clinical efficacy, the loss angle of the NSA, and the loss of HHH showed that for patients with proximal humerus fractures (PHF), there was a significant negative correlation between the postoperative flexion, abduction, external rotation, and internal rotation of the shoulder joint on the affected side, the Constant score, and both the loss angle of the postoperative neck-shaft angle and the height of the humeral head, while there was a positive correlation with the Disabilities of the Arm, Shoulder, and Hand (DASH) score. In the analysis of complications, it was found that the incidence rates of shoulder joint stiffness and internal fixation failure were significantly higher than that of humeral head necrosis. Their occurrences were highly correlated with factors such as age, diabetes, osteoporosis, fracture healing time, rotator cuff repair, rehabilitation methods, medial cortical bone defect, calcar screw, calcar distance, calcar ratio, reduction quality, and so on. In conclusion, in clinical practice, surgical strategies should be tailored to individual patient profiles, incorporating comprehensive preoperative assessments of age, comorbidities (e.g., osteoporosis, diabetes), and fracture morphology. Optimization of surgical precision (e.g., anatomical reduction, calcar screw placement) and adherence to evidence-based postoperative rehabilitation protocols are critical to mitigate risks of complications and maximize therapeutic efficacy.