59 y/o male it been 11 weeks since, I had TKP, & been 3.5 weeks since manipulation, can't bend my knee on my own,
all my muscle had tighten up, try to stretch muscle, noting happening, knee will bend when I'm at rehab, but unable to bend on my own, trying to rehab at home it been hard cause I was taken to much Oxy pain pills, I have cut back to 1@ night & 1 before rehab. now they talking about using a knee brace that will bent the knee over time. have anyone been though this kind of torture?
Can you hire a CPM machine? When my TKR was done last year, I used one in Pysio, & it really helped with the bend. You also need to massage the area quite hard with bio-oil or a cream like E.45, as it breaks down scar tissue. Also, use a stair, or hard box, & do lunges regularly - you will find it moves in a little bit more each batch of 10 you try. Good luck!
Have you tried either sitting in the bath with warm water or a swimming pool that has warm water or a spa/jacuzzi. This will relax you, your muscles and GENTLY allow you to bend without pressure. The trick is not to push too much as your muscles have been assaulted and need to unwind. Think of a good steak, if you marinade and treated it right; it will be tender and juicy. If you hammer at it, pull, stretch it too much; it will be like a piece of leather. It will happen, but not overnight
I had TKR Feb 28 this year. At 12 weeks I had manipulation that brought my bend from 62 to 110. Got the brace and hit 120 after wearing it for 3 months. It's called a Jazz brace. I recommend it as it worked for me. Good luck 
it's different as we know for everyone.