Peter Mayhew’s wife posted this on the Reddit /r/starwars subreddit earlier today:
Hello all!! Angie Mayhew here, my husband Peter is currently in surgery to have both knees replaced.
He wanted to say thank you to all the fans, and wonderful people of Reddit for the kind words, and well wishes.
I will keep all of you updated on when the surgery is completed, and when Peter wakes up.
Here are some pictures we took before he headed in. http://imgur.com/a/FJMUu  .
Stay tuned for more updates.