Does Broken Bone In Half Cast Need Surgery?

Hi I broke a bone in my foot two days ago... It's been put in a half cast , I was told to rest, another doctor who saw my X-ray said I could need surgery, esp if I do not rest properly and keep weight off it... Break is a result of a car driving onto my foot and then reversing off. I can send an X-ray so I am able to get a second opinion....