Hi sarah81,
Have you tried low intensity pulsed ultrasound or electrical stimulation when you had physiotherapy? I am not sure why your medical team does not want to use a bone stimulator. Since you are going to have surgery anyway, there is nothing to loose. The high cost is unfortunate because this is something you could benefit from. Where I am from, a bone stimulator would have been utilized by now, likely resulting in assisted fracture healing. Surgery is always the last resort. In my opinion, regarding a tibial stress fracture, one should only have surgery after all conservative treatments have been exhausted.