Hello @sgp1949, welcome to Connect. I'd like to share the following discussion with you titled, "Scar tissue after knee replacement." It is a long, ongoing discussion on the exact topic of aggressive scar tissue.
Personally, I had the same experience with aggressive scar tissue after my replacement in 2006. I had two manipulations that did not work and I also had a brace that had cranks on it to try and break it up. Eventually, I had a full leg cast put on that had hand cranks on it to try and aggressively break up the scar tissue. None worked, but I kept at it and eventually broke the scar tissue loose on my own. Still, I only have 0-105ish. A second opinion can never hurt, even if you are currently seeing an expert, especially since it involves major surgery.
@sgp1949, while we wait for other members to share their experience, has surgery to remove the scar tissue been discussed? In my own case, they did not want to do so because they did not want to risk infection.