My dad was about 87 when he had his first hip replacement. The private clinic in Quebec had him up the next day shuffling for just a few minutes. Two days later, they discharged him, and by then he was walking, with a walker, up and down the halfway. Also, some minor physio by then.

He was sent home with instructions, including to enlist the help of a physical therapist. I think he may have gone to her (we know her) two or three times, and he figured out he knew what to do and could rehabilitate himself. He did, and was walking for a km within three weeks. Note that it took a LOT of self-discipline, willingness to endure a lot of discomfort and anxiety, and it required perseverance. But if a patient is highly motivated, likes to be in charge, and wants to get back to a near-normal self, it can be done in just a few weeks at most.