By Laurel Lakey, Physical Therapist Assistant, Dee PT, Shelburne
With over 600,000 performed each year, total knee replacement (TKR) surgery is one of the most common and fastest growing surgeries in the United States. According to the American Academy of Orthopedic Surgeons, 90 percent of people who have a TKR experience a substantial decrease in pain. Although most of us are aware of the increased frequency and success of this procedure, the role of physical rehabilitation in preparing for and recovering from surgery is less understood. Here’s how physical therapy plays a part in this process and what you can expect if you are considering this surgery.
A TKR is performed by an orthopedic surgeon and is most commonly used to address end-stage osteoarthritis, which occurs when the cartilage and synovial fluid that cushion your knee joint begin to diminish, causing friction between the femur (thigh), tibia (shin) and patella (knee cap). This can lead to pain and difficulty with everyday activities such as walking, stair navigation and getting up from a chair. A TKR involves replacing the damaged joint surfaces of the femur, tibia and patella with a prosthesis made of plastic and metal components.
Individuals who have been living with a compromised arthritic joint for a period of time may develop a muscle imbalance while compensating for their painful knee. This can lead to weakness and stiffness in the muscles that support and move the knee, often causing difficulty with bending and straightening the knee joint properly. Prior to surgery, your orthopedist may refer you to a physical therapist to learn exercises that can help stretch and strengthen the soft tissues around your knee. Research suggests that improving the muscle performance of your knee in advance of surgery can have a positive effect on both the rehabilitation and long-term success of your new joint. Although physical therapy cannot reverse the arthritic changes in the joint itself, it can improve range of motion and strength leading up to surgery— which can then improve your course of rehabilitation post-surgery.
After surgery you can expect to stay in the hospital for approximately two to three days. It might surprise you to learn that a physical therapist will have you on your feet as soon as the day of or after surgery with the aid of a walker or crutches. Joint replacement surgery differs from other common orthopedic surgeries because it does not involve a direct repair of tendon or ligament tissue. Rotator cuff surgery of the shoulder or ACL surgery of the knee, for example, both require a period of immobilization following surgery in order to allow time for the delicate repaired tissue to heal. In contrast, there is a significantly lower risk of damaging the prosthesis in a TKR, which allows for movement and weight-bearing of the joint much sooner. In fact, most people are able to walk independently without the aid of a walker or cane within two weeks following surgery.
Activating your muscles early on is also helpful in reducing swelling and muscle stiffness and preventing excessive scar-tissue formation around your new joint. Scar tissue is your body’s way of patching together or scaffolding areas of tissue that were disrupted during surgery. Although it is a necessary component of the healing process, profuse and chronic scar tissue can limit the range of motion of your joint. Scar tissue can be thought of as a thick, stiff rope, whereas healthy soft tissue is like a smooth, elastic rubber band. Your physical therapist will instruct and assist you in range-of-motion exercises that will mobilize this scarring and help promote the remodeling of healthy, functional tissue. This part of rehabilitation is usually accompanied by some level of pain or discomfort, but be assured that it poses very little risk of disrupting the new joint itself and will lead to a more mobile, functional joint in the long run.
After being discharged from the hospital, you can expect to have a physical therapist come to your home for approximately two weeks. The therapist will teach you how to perform functional tasks such as getting out of a chair, navigating stairs and walking independently. After two weeks most people are able to attend physical therapy outside of their home. As the swelling resolves and your range of motion returns, it paves the wave for progressing your exercise program and improving your tolerance for daily activity.
You can expect to take part in outpatient physical rehabilitation services twice a week for approximately two to three months. It is important to be diligent in the daily home exercise program your physical therapist will design for you. Your therapist will also work with you on your gait (walking) pattern and balance and will continue to progress your strengthening program. If there is a specific leisure or work- related activity you would like to return to, your PT will help you work on this as well. Once you are discharged from physical therapy treatment you will need to continue with your home exercise program for at least an additional nine months, which will bring you to the one-year mark from surgery. At this point most people can expect a full return to a normal lifestyle.
The idea of recovering from a TKR can often seem like an overwhelming and daunting process. In addition to the support of your orthopedist and physical therapist, it is beneficial to surround yourself with the help and support of your family, friends and loved ones. And remember, committing to your rehabilitation is well worth the effort when you can say that pain no longer limits your ability to enjoy life.
Laurel Lakey lives in Charlotte with her husband, dog and three chickens. You can email her with comments or questions.