I tried to post this earlier but was unable to do so. Therefore if it did manage to go through, I hope I submit the same advice.
I'm sorry to say that usually chicks with deformaties or birth defects don't survive. What you can do is to remove it from the clutch/brood so the other chicks don't pick on him (they will), you can treat it humanely by giving it a comfortable place, food and water, keep it warm and watch over it. Be sure that the box you keep it in has straw or is rough because their developing leg strength depends on good 'footing'. Often they have more than the one defect, some you can see, but others that are unseen (internal etc.) It has been my experience to let nature take it's course as the best approach (for me) but not let it endure undue suffering as it struggles to compete with its siblings. I have seen survivors that didn't seem would make it and lost what seemed to be strong offspring, so cannot tell you it will or will not survive. Still, some breeders 'cull' chicks or animals to protect the flock.