What Causes Pain And Stiffness In Knee After Total Knee Replacement?

I had a right total knee replacement 2 years ago this February and I'm still have really bad pain in the knee. It get really stiff and hard to straighten out ( it makes popping noises). Also getting sweats and pain going up the middle of my right leg and stays there. Could I have bone infection? I really need to know. This had mess up my life and the pain is more now than before the operation. also the Leg is not straight from knee down and it is killing my back when walking. Thanks, Dee Elwell YYYY@YYYY - I need help no doctors will look at my due the first doctor.