Feasibility of reducing perioperative radiography -- analysis of risk factors for internal fixation loosening after closed reduction and internal fixation with Kirschner wire for supracondylar fracture of the humerus in children / 中华创伤骨科杂志

ABSTRACT

Objective:To explore the necessity of perioperative radiography by analyzing the risk factors for internal fixation loosening after closed reduction and internal fixation with Kirschner wire for supra-condylar fracture of the humerus in children.Methods:Retrospectively analyzed were the 502 patients with supracondylar fracture of the humerus who had been treated at Department of Orthopedics, Children's Hospital of Fudan University by closed reduction and internal fixation with Kirschner wire from January 1, 2019 to December 31, 2021. There were 307 boys and 195 girls, with an age of (60.0±27.2) months. There were 224 Gartland type Ⅱ supracondylar fractures and 278 Gartland type Ⅲ supracondylar fractures. Follow-ups revealed internal fixation loosening in 52 cases (set as a loosening group) and no internal fixation loosening in the other 460 cases (set as a non-loosening group). The angles between Kirschner wires (angle 1 and angle 2), the effective fixation ratios of the Kirschner wire (ratio 1, ratio 2, and ratio 3), the metaphyseal shaft angle α, and the distal anteversion angle of the humerus β were measured on the perioperative and postoperative elbow X-ray films and compared. Other data affecting the internal fixation loosening were collected. Multiple logistic regression was used to analyze the risk factors for internal fixation loosening after closed reduction and internal fixation of supracondylar fracture of the humerus. Results:There were no significant differences between the intraoperative and postoperative data in the angle 1 or angle 2 between Kirschner wires (26.58°±14.22° versus 26.75°±10.70°; 41.85°±8.67° versus 41.31°±7.79°), the effective fixation ratio 1, 2 or 3 of Kirschner wire (0.904±0.182 versus 0.887±0.206; 0.897±0.119 versus 0.895±0.142; 0.890±0.035 versus 0.889±0.076), the metaphyseal shaft angle α (86.25°±2.74° versus 85.52°±1.86°), or the distal anteversion angle of the humerus β (31.04°±0.97° versus 29.54°±0.45°) (all P>0.05). Multiple logistic regression analysis showed that fracture site ( P=0.032), fracture classification ( P=0.041) and postoperative infection ( P=0.004) were the risk factors for internal fixation loosening. Conclusions:As supracondylar fractures of the humerus remain stable in the perioperative period with little risk of fracture displacement or internal fixation loosening after closed reduction and internal fixation with Kirschner wire, postoperative radiography is not necessary. The risks for internal fixation loosening are positively correlated with fracture site, fracture type and postoperative infection.