If your knee is already bending to 110 at 10 weeks, you do NOT need an MUA. The information you're getting is very troublesome. Many people need 3-4 months to get back to 110-120, and time will make things improve. I've been down this road with 11 knee surgeries and years of PT following articular cartilage repairs, TKR, and numerous other knee procedures. Adhesions (scar tissue) don't typically cause pain into your upper and lower leg----overworked muscles forced by aggressive PTs pushing on you DOES cause pain. It makes me very angry that you are having increased pain from the PTs pushing/forcing your bend, when the knee needs TIME to heal.
This is a brutal surgery that causes lots of trauma to the soft tissues surrounding the knee. It is NOT like an athletic injury recovery. Those soft tissues need more time to heal than the knee itself sometimes, and they WILL complain, simply because they were pulled/pushed into all sorts of directions while the surgeon was doing your TKR.
I hope you realize I'm just going off of LOADS of experience here with YEARS of PT, plus the 1000's of recovery stories here. Some of my PT was easy, some brutal and forceful, and some in-between. The main point here is that a knee bending to 110 needs no MUA, and recovery takes TIME. I think you're dealing with a surgeon trying to get more of your $$$$. Most surgeons (mine included) won't do an MUA on a knee that bends >95-100-ish. Many here have surgeons who refuse to do MUAs if a need bends to 90, knowing most people get MORE bend in the year or so following the TKR surgery naturally, with no help from a surgeon, PT, or extra exercise. It comes with TIME!!!
I also wanted to add something called "rebound swelling." When PTs pushed/forced my knee to bend more, I usually end up with more swelling/inflammation in the 2-4 days afterwards, often decreasing my bend further. This has happened to me more times than I can count, and I always discuss it with my PTs before we start rehab, as I know my body better than they do after 11 knee surgeries. I have always been very athletic and know my body and how it behave---what it likes and doesn't like, and how I swell. That makes me just as much an expert as the ones with all the initials after their name.
Actually, I bet you a week off from the PT (and any forcing) just might GAIN you a few more degrees of bend. We see it here ALLLLLLL of the time.