answer:My father didn’t have full replacements. He had the meniscus trimmed because he didn’t have the stones to handle knee replacement. He was right. If you get it done, do them both since you will have the same recovery time for each operation. For his repair job, it was 2–3 days, but he took a week. I don’t know more, but he said the replacement involves cutting the bone above and below the knee, then fuse the artificial joint. As for the attachment of muscles, sounds like physical therapy before you’re doing anything extensive. Good luck and may the force be with you.