Independent predictors affecting the reduction of pediatric supracondylar humerus fractures: a retrospective cohort study.

BACKGROUND: Although it is important to understand the risk factors affecting the reduction of pediatric supracondylar humerus fractures (PSHFs), no inclusive study has been conducted so far. We performed a retrospective cohort study to identify the risk factors affecting the quality and difficulty of reduction for PSHFs. METHODS: We reviewed 160 cases with a PSHF that had been surgically treated in our hospital between January 2007 and December 2019. We investigated age, sex, injured side, body mass index (BMI), modified Gartland classification, neurological deficit or an absent radial artery pulse at an initial examination, start time of the operation, waiting time from injury to surgery, operative time, reduction technique, and perioperative radiographic parameters. We calculated independent predictors of unsuccessful closed reduction, prolonged operative time, and malreduction using multivariate analyses. RESULTS: In a logistic regression analysis, modified Gartland type III was a significant predictor of unsuccessful closed reduction (OR 14.50 [95% CI 4.03-51.90]; P < 0.01) and BMI was a significant predictor of malrotation (OR 1.59 [95% CI 1.06-2.39]; P = 0.025). In a multiple linear regression analysis, BMI and open reduction were significant predictors of prolonged operative time (BMI, P = 0.011; open reduction, P < 0.01). CONCLUSIONS: If closed reduction fails, we should not hesitate to immediately switch to other methods. Obesity was an independent predictor of both prolonged operative time and malrotation, a finding that has not been previously reported. Rotational alignment should be carefully checked, especially for obese children, and accurately be reduced. Open reduction also extended operative time.