Analysis of the factors that are important in re-displacement in pediatric diaphyseal femur fractures treated with a spica cast

Abstract Background There is no detailed data on the factors affecting the re-displacement in pediatric femoral fractures treated with closed reduction and early spica casting. This study aimed to investigate the factors effective in re-displacement in pediatric diaphyseal femur fractures (PDFF) treated with spica casting. Methods In all, 151 displaced PDFF were evaluated retrospectively. Demographic data of the patients were evaluated. Type of fractures, anteroposterior and lateral angulations, amount of shortening, translation ratio, cast index (CI), gap index (GI), and three-point index (TPI) measurements were evaluated radiologically. Thigh flexion angle (TFA) and knee flexion angle (KFA) were measured. After casting, angulation of more than 10° in any plane and a shortening of more than 10 mm was accepted as re-displacement. Binary logistic regression analysis was used to evaluate the risk factors of re-displacement. Receiver operating characteristic analysis was performed for TFA and KFA. Results Re-displacement was detected in 40 patients (26.5%). Transverse type fracture (p = 0.001), TFA ˂71.4° (p Conclusion When treating a PDFF with spica casting, one should be aware of re-displacement if the fracture type is transverse, TFA is ˂71.4°, and KFA is ˂52.6°. Level of evidence Level III, prognostic