Scar tissue after knee replacement

I had knee replacement surgery 6 weeks ago . Through PT I have been working on breaking up the scar tissue only for it to regrow by the time I get back to PT two days later. I have been massaging at home, using a hand held massager and roller. It is painful and swollen. I am getting very disheartened. Any suggestions as to what else I can do. Has anyone had laser treatments to break up scar tissue? Were they effective?