In the 90's my grandma had her knee replaced. She was bed-bound for 2 weeks before they'd start physical therapy to get her knees back in order. (Ironically enough, her first knee was recalled...so she had a total of three knee surgeries Left, Right, then Left again) over a span of 11 years.
In 2018, my mom had her left knee and right knee done at the same time...and they had her up walking the halls of the floor the next day and was back at home less than 72 hours after her surgery, and she's walking just fine these days without any assistance.