I m having pain that starts behind knee and generates from the heel up to buttock on my left side. The knee has had meniscus repair surgery and knee replacement is in my future but the joint isn t giving me pain. I get swelling behind the knee. I have problems riding in a car because the seat hits me on the back of the leg above the knee and pain is like I said the entire length of the leg including the hip. If I roll over on the other side the pain goes away. I have spinal stenosis on the right side of my spine and that has gotten better since I had my right knee joint replaced. I have problems getting comfortable at night. Have to put pillows under the knee.