Risk factors for limb overgrowth after the application of titanium elastic nailing in the treatment of pediatric femoral fracture

The objective of this study was to discuss the risk factors of postoperative limb overgrowth after the application of titanium elastic nailing (TEN) in the treatment of pediatric femoral fractures as well as analyze the causes and provide guidance for clinical treatment. The study included children with femoral fractures who were treated with TEN at our hospital from February 2005 to December 2009. Their age, gender, weight, cause of injury, having head trauma or not, fracture site, fracture type and nail-canal diameter (NCD) ratio were recorded. Student’s t-test, chi-square test or Fisher’s exact test was used for univariate analysis of the above factors, and then multivariate logistic regression analysis was used to analyze the possible risk factors in order to determine which ones are associated with limb overgrowth after the application of TEN to treat children with femoral fractures. Univariate analysis showed that the age, gender, weight, cause of injury, having head trauma or not, and the fracture site did not have a statistically significant association with limb overgrowth (P = 0.741, 0.900, 0.253, 0.739, 0.967 and 0.105, respectively). The fracture type and NCD ratio were significantly associated with limb overgrowth (P = 0.003 and 0.000, respectively). Multivariate logistic regression analysis demonstrated that the fracture type (P = 0.021, OR = 2.757) and NCD ratio (P = 0.002, OR = 2.422) were independent risk factors for limb overgrowth. The main factors affecting postoperative limb overgrowth are the fracture type and NCD ratio. In order to avoid limb overgrowth, unstable fractures should be fixed as firmly as possible, and the NCD ratio should be ≥0.8.