Health Society of South Africa

TOTAL KNEE REPLACEMENT

Replacing Your Problem Knee

A painful, stiff knee can keep you from doing the simple things in life, even walking without pain. Now your orthopaedic surgeon can replace your problem knee, thanks to breakthroughs in surgical techniques and materials. After a total knee replacement, you'll have some restrictions on using your new knee, but you can look forward to returning to many of your activities of daily living.

When Walking Hurts
As your knee pain and stiffness increase, simply walking or climbing stairs can hurt. Using a cane or crutches may no longer be enough to help you get around.

Knee pain and stiffness result from osteoarthritis (the breakdown of cartilage in your joints) from injury or wear and tear. Other knee problems include rheumatoid arthritis (an inflammatory joint disease) or poor alignment of your leg bones.

Your New Knee
Total knee replacement means resurfacing the bones of your knee joint with a prosthesis (artificial knee joint). Of the three surfaces in your knee that may become roughened and painful, you may need one, two or all three replaced. Total knee surgery is now as safe as total hip surgery, although your knee is a more complex and less stable joint than your hip.

Your Knee Anatomy

You can walk easily and without pain only when the bones in your knee joint are smooth and cushioned by healthy cartilage. You also need strong muscles and ligaments for stability, because your knee is more than a simple hinge joint. Each time you bend your leg to walk or climb up stairs, the bones rotate, roll and glide on each other.

A Normal Knee
In a normal knee, smooth weight-bearing surfaces allow for painless movement. Muscles and ligaments give you side-to-side stability. Your synovial membrane lubricates the joint.

A Problem Knee
With osteoarthritis, your cartilage "cushion" wears away, bones become rough and rub together, causing pain. With rheumatoid arthritis, your joint may also be inflamed and swollen.

A Knee Prosthesis
Like a normal knee, your prosthesis has smooth weight-bearing surfaces. The femoral component covers your thighbone, the tibial component covers the top of your shinbone and the patellar component covers the underside of your kneecap.

Your orthopaedic surgeon chooses the best prosthesis design, either cemented or cementless, for your knee.

Your Orthopaedic Evaluation

Your orthopaedic evaluation helps your surgeon determine if you're a candidate for a total knee replacement, and, if you are, to choose the best prosthesis for your particular knee problem.

Your medical history includes questions about knee pain, medications you may be taking, prior injury, infections, bleeding disorders and other bone and joint problems you may have.

Your physical examination includes assessing your range of motion (stiffness or instability), any deformity in your legs (bowlegged or knock-kneed) and watching how you walk and sit.

Your x-rays show the degree of damage and deformity in your knees, and help in the selection and precise fitting of your prosthesis.

Deciding on Surgery
After your evaluation, you and your surgeon can discuss whether total knee replacement is the best treatment for you at this time. Your surgeon may instead recommend medications, injection therapy, physiotherapy or a different surgical procedure.

Understanding the risks and complications is part of your decision. Your surgeon can talk with you about infection, blood clots, pneumonia, prosthesis loosening, nerve loss or other postoperative risks before you decide on total knee surgery.

Before Surgery
Continue leading a normal, healthy lifestyle and be sure to let your surgeon know about any infections or leg sores. You may be asked to have a physical examination with your regular doctor. Because you may need blood transfusions during surgery, you may want to donate your own blood before your hospital stay.

Your Hospital Recovery

The morning of surgery, you'll have an IV (intravenous) line started for medications before you're given general or spinal anaesthesia. You and your family can expect your surgery to take from two to three hours, depending on how much knee damage you have and whether you need all three of your knee bones resurfaced.

In the Recovery Room
After surgery you may wake up feeling a bit groggy. Specially trained nurses will be with you to keep you comfortable and provide pain medications. Your nurses also coach you with coughing and deep breathing exercises to help clear your lungs and prevent postoperative complications after surgery. You'll have a large dressing on your knee with a drain for normal post-op bleeding. Once you're awake and alert, you'll be transferred to your hospital ward.

Your Hospital Recovery

Once you're back in your room, the goal for the rest of your hospital stay is to begin walking again before you go home. You'll be started on a physiotherapy programme to exercise your knee muscles and regain strength and range of motion in your new knee.

Initial Healing
During your first few days of recovery, you're asked to wiggle your toes or do other easy exercises to improve the circulation in your leg. Your knee may also be exercised by a machine that moves your leg for you (a continuous passive motion machine).

Physiotherapy
Physiotherapy, a vital part of your knee recovery, helps you regain your full knee potential. Gentle knee exercises strengthen the muscles around your new knee and help restore its range of motion. Your physiotherapist will design a programme especially for you and teach you how to do the exercises. Your therapist also starts you walking, a few steps at a time, to promote healing. Progressing from a walker to crutches and then a cane helps you regain confidence and your normal walking motion.

Going Home
Once you've recovered and can bend your knee enough to go home, your surgeon discharges you. Your nurses can help make arrangements for going home. Your sutures and bandages are usually removed before you leave the hospital, and you're given instructions for a safe home recovery, which often includes follow-up physiotherapy. Feel free to ask any questions you may have.

Your Home Recovery

At home again, your new goal is to return safely and comfortably to your activities of daily living. Your follow-up physiotherapy relieves any stiffness and awkwardness you may still feel, and helps you regain independence as you learn to care for your new knee.

Follow-up Physiotherapy
Your physiotherapist instructs you to continue with the exercises you learned in the hospital and may teach you others, as well. Strength exercises tone your thigh muscles, which have the greatest control over your new knee. Range-of-motion exercises help you bend and straighten your knee more fully.

Strength exercise. Tighten your thigh muscle and lift your leg 20 to 30 cm. Hold for 4 to 6 seconds. Slowly lower and repeat 10 times.

Range-of-motion exercise. Slowly lift your foot to the front and then press it under you as far as possible. Repeat 10 times.

Caring for Your New Knee
Your knee prosthesis is the result of years of research. But as with any other device, your new knee's life span depends on how you care for it. In your follow-up visits after surgery, your surgeon will follow your progress and answer any questions you may have about caring for your new knee.

Follow your surgeon's advice on using crutches or a cane to keep weight off your heeling knee.
Keep in mind that your prosthesis is designed for activities of daily living, not sports.
Before dental work or surgery, let your doctor know you have a prosthesis: Antibiotics may be needed to help prevent infection.
If your prosthesis wears out or loosens, it can be replaced with another. Revision surgery is difficult, however, so preserve your new knee.

Call your surgeon if you have increased knee pain, swelling, incision drainage, chest pain, shortness of breath or any other symptoms you don't fully understand.

Enjoying Your New Knee

After a total knee replacement, you can look forward to less knee pain, stiffness and deformity in your leg. While your new knee is not a normal knee, you can expect to enjoy your activities of daily living with greater ease and comfort. You can once again enjoy life more fully with a more independent, mobile lifestyle.

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