Vitamin and physical therapy may help. It's worth a try.
You need to hobble the legs to bring them into alignment, and rig a chick "shoe" for the curled toes on the left foot. Then rig a chick chair to teach the chick's body to accept an upright position. I'll give you some links for more information on these steps.
The vitamin therapy consists of a vitamin E capsule daily mixed into soft boiled egg. The chick will be able to eat this from the chick chair you rig. Mix a vitamin B-complex tablet into its drinking water each day, also. You will need to encourage the chick to drink from its chair or syringe the water into its beak.