Systems and methods are provided for fixation of a fractured bone with an intramedullary bone fixation device. During an implantation procedure, the fixation device may be guided by a removable guidewire which is not coupled to the fixation device. The guidewire and device may be inserted into an intramedullary canal along a pathway which is not parallel to the intramedullary canal. The fixation device may be composite, formed of a support structure and a matrix material. The matrix material may be thermo-chemically activated, transformable from a deformable first thermo-chemical state to a hardened second thermo-chemical state. The fixation device may be radially expandable to deform to the shape of the intramedullary canal, to provide support to the fractured bone.