Objective:To study the effect of nerve growth factor(NGF)on bone fracture healing of inflicted T_(10)spinal cord injury(SCI)complicated with tibia fracture in rats.Methods:Totally 120 rats were randomly divided into tihia fracture group (F group,n=40),T_(10)SCI+tibia fracture group(FS group,n=40),and T_(10)SCI+tibia fracture+NGF group(FSN group,n=40).Four weeks later,the fracture sites in the 3 groups were subjected to CT scanning;the maximum transverse diameter of the fracture ends and the gray scales of non-osseous area were measured;the changes of biomechanics property of the fracture ends were determined by three-point bending test;the bone morphometry,bone density,and histomorphology of callus were determined;the expression of OCN was detected by immunohistochemical method;the osteoblast ultrastructure was observed by TEM and the expression ofⅠ,Ⅱtype collagen were examined by Western blotting.Results:The maximum transverse diameter of F group was less than those of FS group(P