Remodeling of Rotational Malunion of Femoral Shaft in Children.

Abstract

The degree of expected rotational remodeling in femoral shaft fractures is poorly understood, partly because of the difficulty in accurately measuring rotational alignment radiographically before and after treatment. This study aimed to assess the degree of rotational remodeling in the short-term following post-traumatic fracture shaft of the femur with > 10° rotational malunion in children under 15 years. We carried out an observational study with a prospective follow-up on 18 children aged < 15 years with isolated, unilateral, oblique, or spiral, closed femur shaft fracture treated with closed reduction and immobilization with hip spica or internal fixation with elastic stable intramedullary nails or minimal invasive plate osteosynthesis. Only those with an initial axial malalignment measured on postoperative reduction radiographs of more than 10° by Ozel et al. technique were included. We evaluated the residual rotational malunion outcome using the ultrasound technique of Terjesen et al. by assessing the difference in femoral torsion as a guide to rotational malunion. The difference between the initial malreduction and the torsional difference between the hips at follow-up was deemed the extent of rotational change or remodeling. The mean axial malalignment was 21.6° (10°-32°). The mean rotational remodeling was 13.6° (range 7°-21°), with an SD of 3.9. This study shows that a significant amount of rotational remodeling occurs in children up to 14 years of age within 2 years of injury. It is higher in younger patients (<i>r</i> = 0.786; <i>p</i> < 0.001), and the extent of remodeling is proportional to the magnitude of the initial deformity (<i>r</i> = 0.81, <i>p</i> < 0.001).