I had lost 65lbs prior to my TKR. I do have to say it made a difference before and I'm sure it did after. They said nothing to me about losing after but it's always good to lose weight. It gets harder after the surgery because even a year out my leg/knee area still gets sore and stiff. Feel best wearing jeans as they give compression to my leg and knee an it's supported more (per PT). I've read that even mild weight loss takes several pounds of impact off the knees so I'd say it would make a difference.