If you don't wear a cast or a boot for a broken fibula and tibia what will happen because I take my boot off a lot.?

Cast removal: early. The bones may not heal properly, perhaps heal crookedly ( out of alignment) or not heal at all ( malunion, i think) or may luckily heal ok. How long have you been casted? When you remove the cast , do you walk on the foot? Or use crutches? Older you are , greater the risk of (the above) occurring. Why do you remove the support? Itching. Poor fit? Hurts? Best to discuss with your doctor!