hi, thank-you for providing the brief history. As the surgery was failure trying the trying the iliazarov ring fixator should work well but may need a bone graft as well. Since the previous surgeries were failure a thorough attention is advised in terms of checking the gaps formed due to previous implants. Bone graft should make some help for healing process to be optimum provided the limb is stabilized properly and all measures of Vitamin D3 supplement and calcium supplement is taken. Now since it s a femur you need to be conscious while making a new approach since he might have a lot of pain and the infection should be controlled before hand so the new technique do not fail. Regards Jay Indravadan Patel