Can flexible intramedullary nails provide proper fixation of long bone fractures in patients weighing over 100 pounds?

Abstract

Purpose: Length stable diaphyseal femur and tibial shaft fractures in paediatric patients may be fixed with flexible intramedullary nails (FINs) in selected paediatric patients. Previous studies based on biomechanical models have suggested that the forces of gait may overcome the stability of this construct in patients weighing more than 45 kg. Surgeons occasionally use FINs for fixation in patients outside this limit. The purpose of this study was to evaluate whether FINs could be used in paediatric patients weighing over 45 kg without increasing the rate of complications. Methods: A retrospective cohort review was performed for 12 patients weighing over 45 kg with femoral or tibial fractures treated with FINs, matched 1:2 for gender and bone type with 24 patients weighing less than 45 kg; also with femoral or tibial fractures treated with FINs over the same period. Results: There was no significant differences in rate of major complication or increases in angulation between the study and control group. The study group had major complication (8.3%) of hypertrophic nonunion in the tibia, and the control group had one major complication (4.2%) of increased anterior bowing in the femur. The odds ratio of developing a major complication in the study group was 2:1 which was not significant (p = 0.06). Conclusions: FINs can be considered as a treatment option for fixation of femoral and tibial fractures in a select group of paediatric patients weighing more than 45 kg. Clinical and functional outcomes measurements in larger sample sizes are needed before making any definitive conclusions.