I didn't have any luck fixing my 1 day old banty chick's leg even though it was hobbled for almost 2 months. It just never went back into place, but she is living a good life now inside in a bird cage. She has learned to get around by balancing with her bad leg and her wings. I even take her outside a few times a week for grass and dirt. It's not an ideal life I know for a chicken, but she seems happy and adjusted with her life. She really doesn't know anything different since she has been like this since hatching. I give her vitamins in her water all the time and once a month do Polyvisol for a week since she does have a problem with curled toes.
Just the other end of the spectrum for you....