Greetings
Zerex,
At this point you should concentrate on giving supportive care to the sick chicken and nursing it. A sick chicken's recovery will depend largely on the amount of nursing and supportive care you can give.
You can have the best medications available, but if the sick bird must survive harsh temperatures, and struggle to compete for food, the chances are they will not make it. No one is suggesting that you do any kind of surgery, either. That is for a vet to do.
Try and make the chicken more comfortable first. Observe her and note any symptoms. Write them down. Is she off feed? That is important to know, too. She needs to eat to recover. If you are feeding supplemental meals, what do they consist of. A supplemental meal should have carbohydrates (
Cooked brown rice, wheat berries, oat groats, potato, etc.), protein (egg, cooked minced meats, cooked fish, tofu, etc.), Vegetable matter (chopped greens, cooked frozen vegies, cucumber, tomato), fruit (diced grapes, apple, melon, tomato etc.), and fats (butter, coconut oil, peanut butter) use these to cook with or drizzle on food.
Because the hen is drinking water on her own, she may not need electrolytes. But, you may add them in the water if you have some. Do it for 3 days.
Next, I would like you to feel the good leg. Note if the temperature is warm. Then, feel the bad leg. Is it cool or cold? Report your findings.
We've all been there. Frustrated and fearful that we cannot save our beloved chicken. It's part of having animals of any kind. Step away when you need to. And except that not all things can be fixed. Do you best, and do it with kindness and compassion. Then, if it's not enough, it will be more than millions of precious chickens get throughout the world.
God's blessings and peace to you.