After 5 months in the hospital and the rehabilitation center for these health issues, my dad has returned back home. His hip and leg have sufficiently cured to walk again, also on staircases. Nevertheless his health remains a challenge. We've had a lot of worries in the past months and some tough discussions about the future and the fact that he's home now does not change that. But I'm happy for my mom and dad to be reunited in their home while it is still possible.
The children might regret their little rides in the wheelchair in the rehabilitation center though :D.