I'm sorry the MUAs didn't help. It would have been great if they had.
But, their failure to help does prove that you don't have bad scar tissue (adhesions). That's a gold thing, because now you know that there's nothing permanent stopping your knees from bending.
What's preventing the bending now is soft tissues irritated and swollen by exercises and over-zealous PT therapy. Your first PT therapist was brutal and I think your knees are still suffering as a result.
Your poor knees need time, rest and gentle treatment, with lots of icing and elevation, so they can calm down and get rid of the swelling.
It's not exercising that gets you your ROM - it's time. Time to recover, time for swelling and pain to settle, and time to heal. Your knee is capable of achieving good ROM right from the start. Its ROM will gradually increase as your knee heals and the internal and external swelling decrease.
There's no need to rush to get ROM (Range of Motion) because it can continue to improve for a year, or even much longer, after a knee replacement. There isn't any deadline you have to meet:
Myth busting: the "window of opportunity" in TKR
You're only 3 months into a year-long recovery, so those knees have
at least 9 more months in which to gain ROM.
Have a look at these two examples and see how a couple of other members had slow, but successful improvement in their ROM:
This is from Campervan. As you can see, her flexion continued to improve for a long time.
"I had a slow recovery. Here's my flex measurements at various points:
92 - 8 weeks post op
105 - 10 weeks
107 - 5 months
110 - 6 months
112 - 7 months
116 - 9 months
119 - 11 months
118 - 1 yr
120 - 1yr 2 months
125 - 1 yr 8 months
128 – 6 years "
And this one is from bertschb:
I'm 12 months out from my surgery and have some advice based on my experience:
1- Stop going to PT (all it will do is make your knee swell and reduce ROM)
2- Don't worry about your ROM
3- Be patient - VERY patient!!!
Here is my ROM history (more or less):
1 month - 60 degrees
2 months - 80 degrees
3 months - 85 degrees
4 months - 90 degrees
5 months - 90 degrees
6 months - 110 degrees
7 months - 120 degrees
8 months - 125 degrees
9 months - 130 degrees
10 months - 135 degrees
11 months - 140 degrees
12 months - 140 degrees
I spent waaaaay too much time worrying about ROM. I thought I'd be riding my bike a couple months after surgery but it took SIX months! Looking back on my surgery, if I knew then what I know now, I wouldn't have wasted my time with PT and I wouldn't have worried about ROM.