When damage to the knee prevents the joint from moving smoothly, additional stress and pressure is put on the tissues, ligaments and tendons, surrounding the knee, causing them to overwork. For instance, a bent knee is a knee attached to a hamstring muscle that is always in a shortened contraction. Such constantly stressed tissues are more likely to stiffen and develop adhesions among the tissue fibers. While the damaged ends of the femur and tibia are replaced with new components made of metal, alloys of cobalt-chromium and titanium, and strong durable plastic, polyethylene, the worn, overly-stressed tissues in the knee remain. If these words describing anatomy are not part of your recovery vocabulary, check the glossary section.
Now it is your job, working with your PT, to help these tissues adapt to the new knee through exercises that stretch and strengthen, and, unfortunately, hurt. I found it was much easier to do these exercises when I began to understand the structure of the knee and leg and could speak with my PT on a more informed basis. I greatly admire my PTs. They are highly educated and dedicated professionals, who spent years learning about the human body – how it works, what can go wrong and how to motivate patients to perform exercises they would rather not do. They were also kind enough to tolerate my endless questions and I have – after a period of months–acquired enough knowledge to be able to share my basic understanding of what matters in TKR rehab.