You don't have to decide to cull for a while. The chick in my profile photo had the same issue, but even worse. His leg literally pointed in the opposite direction. Wasn't a slipped tendon or anything like that. Ollie didn't respond well to splinting at all.
He was quite active, but he had some real issues getting around, so I decided to amputate the leg. He responded very well, learned to stand upright, and was an excellent hopper. Sweetest chick I think I've ever had.
If Henry can get off the ground and make it to nourishment, you can leave him. If he's stuck on the ground like Ollie was, I would cull or if you have your heart set on keeping him, amputate. You just have to be prepared to lose Henry because of the process or even if he recovers, due to predatory issues. Ollie didn't stand a chance against a predator and neither would Henry.
I really hope this helps and that everything works out.