Spinal Cord Injury Causes More Damage to Fracture Healing of Later Phase than Ovariectomy in Young Mice

Abstract

The purpose of this study was to compare the effects of spinal cord injury (SCI) and ovariectomy (OVX) on femoral fracture healing of later phase in young mice. Sixty young female C57 mice were randomized into three groups: SCI, OVX, and age-matched intact control. The femoral fracture was generated at 3 weeks after SCI or OVX. At 1 month after fracture, the femoral fracture area was evaluated through the healing status using radiograph; bone mineral density using dual X-ray absorptometry; callus formation and mineralization and neovascularization in callus using micro-computed tomography; biomechanical analysis using testing machine; and histology analysis by staining with hematoxylin-eosin stain. SCI mice showed lower bone mineral density in the femoral callus as compared with OVX mice. Callus geometric microstructural parameters of the femora in SCI mice were significantly lower than OVX mice. SCI induced significant changes of biomechanical parameters in the femoral fracture healing area. The callus formation and callus neovascularization in SCI mice were significantly lower than in OVX mice. SCI induces more deterioration of fracture healing in the femoral diaphysis than OVX.