I've had both and hip replacement is a piece of cake compared to TKR. Everyone told me the first 2 weeks were tough. Boy were they right! But after 2 weeks, the pain became less, and slowly but surely, much less pain than before TKR. PT is so critical. I had been through PT for a tibia plateau fracture where ROM bending was crucial, but I didn't understand until I had to work at it that straightening the leg is also crucial after TKR. I've heard from others, and my PT emphasized, if you don't get ROM back quickly, you may never get it back. An ice machine is a tremendous help, continuous movement and an encouraging physical therapist are critical!