I didn't use a CPMmachine at all. My surgeon did not believe they really did matter in the ultimate outcome. I was at 80 degrees the day after surgery. Now 9 weeks out, I am at between 130 and 140 unaided, and 0 extension. That being said, everyone recovers range of motion differently!!! You will continue to get ROM for an entire year as the knee and surrounding tendons and muscles heal. Don't lose heart, and don't let your PT push you or threaten you. If you had decent range of motion before the replacement, you will get it back with time. Hang in there my dear. This recovery takes time, time, time