D came through the surgery okay, and I brought him home last night.
He spent the night on the couch - he said that he didn't think he'd be able to manage the stairs last night (was full of percocet and still drowsy from the anesthesia) - and when I got up this morning he was walking around the kitchen on his crutches.
He's been bearing a little weight on his leg today and has been using his CPM (Continuous Passive Motion; it bends and straightens his knee a few degrees) and pain meds religiously.....and he's even been letting me look after him without complaining.
He is, in other words, doing really, really well. Better than expected - much better.
Thank you all for your thoughts, prayers and good wishes. Both D and I very much appreciate them!