Effect of Deltoid Tuberosity Index on the Outcome of Proximal Humeral Fracture Treated with a Locking Plate

Background: In the elderly, proximal humerus fractures are not unusual. The treatment of these injuries are often complicated. Objectives: This study aimed to evaluate the effect of deltoid tuberosity index on the outcome of proximal humeral fractures treated with a locking plate. Methods: One hundred consecutive patients with displaced fractures of the proximal humerus had open-reduction and internal fixation using a locking plate. The patients were divided into two main groups (low density group) DTI<1.4 and DTI>1.4 (normal density group) and at the end of the study, treatment and failure were assessed in the two groups. Results: In this study, 100 patients with proximal humeral fracture who were candidates for locking plating surgery were evaluated. The mean of DTI in all patients was 1.48 with a minimum of 1.10 and a maximum of 2.20. Based on the Pearson correlation coefficient, with increasing age, the constant score decreased in the studied patients, which was statistically significant (r=-0.216, p-value = 0.031). Also, in patients with DTI less than 1.4 and more than 1.4, the Constant score was 73.02 and 77.88, respectively. This difference was not statistically significant ( p-value=0.054). There was a statistically significant relationship between Constant Score, DTI and patients' gender (p-value=0.05). While there was no statistically significant relationship between fracture type and constant score. Pearson correlation coefficient between DTI and age of patients was -0.30, which decreased with increasing age of patients. This was statistically significant (r=-0.30, p-value=0.003). Conclusion: The results of this study show that the deltoid tuberosity index can be effective on proximal humoral fracture surgery treated with locking plating.