I had a partial knee replacement on my left knee in 2010. A CPM was used on my knee for the first two weeks. I think the CPM machine was of significant benefit in my healing after surgery. I was able to start physical therapy three days after the surgery . My knee healed quickly and my range of motion was 130° and 0° within 10 weeks after the surgery. That knee is rarely painful. My right knee is now bone on bone and has frequently been painful. I am not a candidate for TKR surgery due to heart problems. I find that if I do frequent gentle exercise ( 5-10 minutes each hour) the pain is minimized.