Though I had an outpatient knee done last year I did have a friend spend the first night with me; just to make sure there was no bad reaction or emergency. After that, I managed on my own.
Post operation, the hospital must assure you can at least walk safely (with walker or similar assist) and take care of those "personal" things that concern you.
No medical facility should discharge someone to live alone unless those basic necessities of daily life can be handled.
If I were in your situation, I would make it totally clear up front that if your capabilities don't meet that standard then you be admitted for at least one night in the hospital (or a hospital if the procedure is done in a totally outpatient facility) WITH Physical Therapy to meet the standard of handling daily living activities.
Remember, it's normal now to wake up from the operation, get up form the gurney, walk (with a therapist beside you), climb a couple stairs, walk back and sit/lay down under your own power.
Good luck and God Speed on your successful recovery