My treatment was at a private Hospital but paid for by the NHS, this is the norm in our area for Hips/Knees which are likely to be straight forward.
I guess the recovery is influenced by the skill of the surgeon and his recovery team along with the age / fitness of the patient. My physio started 2 weeks before the surgery to strengthen the muscles.
Even though I was home on day 4, I could bend my knee 90 degrees (an essential way point), walk probably 200 yds and climb up/down stairs on the third day. (with crutches).
The Physios worked non stop to get the knee moving, it would have been a waste of everyone's time for me to remain after the fourth day, after that it was down to my own perseverance to improve further.
My staples come out next week and I would hope that I will be down to sticks when I see the Physio after they come out.
I would hate to have been in hospital any longer, I had (ridiculous) plans that I would be able to drive myself to next weeks appointment.
Getting on well atm, been walking each day for about 10 min, (even dead headed some roses this morning) can wash myself if my wife gets things ready for me. I can manage the stairs to get to/form bed, however I would struggle without my wife's help, but that was part of my pre assessment. My home has been modified to help, extra stair and grab rails, raised toilets and chairs etc.