Total knee replacement surgery

A total knee replacement replaces the worn ends of the thighbone (femur) and the lower leg bone (tibia) where they meet at the knee. Sometimes the surface of the patella (kneecap) is replaced too. You may want this surgery if you have knee pain, stiffness, swelling, or problems moving your knee that you cannot treat in other ways. For most people, these problems are caused by arthritis. They can also be caused by a knee injury.

If you need to have both knees replaced, you may have both surgeries at the same time. Or your doctor may recommend doing one knee at a time. Your doctor would replace the second knee after you recover from the first knee surgery. Recovery after a double knee replacement takes longer than after a single replacement.

Before surgery, you will get medicine to make you sleep or feel relaxed. If you will be awake during surgery, you will also get a shot of medicine into your spine to make your legs numb.

There are two types of replacement joints. They are:

• Cemented joints. The cement acts as glue, attaching the new joint to the bone.
• Uncemented joints. These have a metal coating with many small openings. Over time, new bone grows and fills up the openings. This new bone attaches the joint to the bone.

Your doctor may also use a combination of cemented and uncemented parts.

Your doctor makes a cut, called an incision, on the front of your knee. Your doctor then:

• Replaces the damaged part of your femur with a metal piece.
• Replaces the damaged part of your tibia with a metal piece and plastic surface.
• May replace part of your kneecap with plastic.

The doctor finishes the surgery by closing your incision with stitches, staples, skin glue, or tape strips.

Most people have a lot less pain after knee replacement surgery and are able to do many of their daily activities more easily.

• The knee will not bend as far as it did before you had knee problems. But the surgery will allow you to stand and walk for longer periods without pain.
• After surgery, you may be allowed to resume activities such as riding a bike, swimming, walking for exercise, dancing, or cross-country skiing (if you did these activities before surgery).
• Your doctor may tell you not to run, play tennis, squat, and do other things that put a lot of stress on the joint.

Most knee replacements (about 90 out of 100) last about 20 years.

The younger you are when you have the surgery and the more stress you put on the joint, the more likely it is that you will later need a second surgery to replace the first artificial joint. Over time, the components wear down or may loosen and need to be replaced.

Your artificial joint should last longer if you are not overweight and you do not do hard physical work or play sports that stress the joint.

If you wait to have surgery until you have already lost a lot of your strength, flexibility, balance, endurance, and ability to be active, then after surgery you might have a harder time returning to your normal activities.

Knowing what to expect before surgery can help you prepare.

• Be sure you understand the risks, benefits, and other treatment options.
• Tell your doctors ALL the medicines, vitamins, supplements, and herbal remedies you take. Some of these can increase the risk of bleeding or interact with anesthesia. Your doctor will tell you which medicines you should take or stop before surgery.
• If you have an advance directive, tell your doctor. Bring a copy to the hospital. If you don't have one, you may want to prepare one. It lets your doctor and loved ones know your health care wishes.
• You may need to shower or bathe with a special soap the night before and the morning of your surgery. This may help prevent an infection.

Activity

• Rest when you feel tired. You may take a nap, but don't stay in bed all day. When you sit, use a chair with arms. You can use the arms to help you stand up.
• Work with your physical therapist to find the best way to exercise. What you can do as your knee heals will depend on whether your new knee is cemented or uncemented. You may not be able to do certain things for a while if your new knee is uncemented.
• After your knee has healed enough, you can do more strenuous activities with caution.
  • You can golf, but you may want to use a golf cart for some time. And don't wear shoes with spikes.
  • You can bike on a flat road or on a stationary bike. Talk to your doctor before biking uphill.
  • Your doctor may suggest that you stay away from activities that put stress on your knee. These include tennis, badminton, contact sports like football, jumping (such as in basketball), jogging, and running.
  • Avoid activities where you might fall.
• Do not sit for more than 1 hour at a time. Get up and walk around for a while before you sit again. If you must sit for a long time, prop up your leg with a chair or footstool. This will help you avoid swelling.
• Ask your doctor when you can drive again. It may take several weeks after knee replacement surgery before it's safe for you to drive.
• When you get into a car, sit on the edge of the seat. Then pull in your legs, and turn to face the front.
• You should be able to do many everyday activities 3 to 6 weeks after your surgery. You will probably need to take 4 to 16 weeks off from work. When you can go back to work depends on the type of work you do and how you feel.
• Ask your doctor when it is okay for you to have sex.
• For 12 weeks, do not lift anything heavier than 10 pounds and do not lift weights.

Diet

• By the time you leave the hospital, you should be eating your normal diet. If your stomach is upset, try bland, low-fat foods like plain rice, broiled chicken, toast, and yogurt. Your doctor may suggest that you take iron and vitamin supplements.
• Drink plenty of fluids (unless your doctor tells you not to).
• Eat healthy foods, and watch your portion sizes. Try to stay at your ideal weight. Too much weight puts more stress on your new knee.
• You may notice that your bowel movements are not regular right after your surgery. This is common. Try to avoid constipation and straining with bowel movements. Drinking enough fluids, taking a stool softener, and eating foods that are good sources of fiber can help you avoid constipation. If you have not had a bowel movement after a couple of days, talk to your doctor.

Medicines

• Your doctor will tell you if and when you can restart your medicines. You will also get instructions about taking any new medicines.
• If you stopped taking aspirin or some other blood thinner, your doctor will tell you when to start taking it again.
• Your doctor may give you a blood-thinning medicine to prevent blood clots. If you take a blood thinner, be sure you get instructions about how to take your medicine safely. Blood thinners can cause serious bleeding problems. This medicine could be in pill form or as a shot (injection). If a shot is needed, your doctor will tell you how to do this.
• Be safe with medicines. Take pain medicines exactly as directed.
  • If the doctor gave you a prescription medicine for pain, take it as prescribed.
  • If you are not taking a prescription pain medicine, ask your doctor if you can take an over-the-counter medicine.
  • Plan to take your pain medicine 30 minutes before exercises. It is easier to prevent pain before it starts than to stop it after it has started.
• If you think your pain medicine is making you sick to your stomach:
  • Take your medicine after meals (unless your doctor has told you not to).
  • Ask your doctor for a different pain medicine.
• If your doctor prescribed antibiotics, take them as directed. Do not stop taking them just because you feel better. You need to take the full course of antibiotics.

Incision care

• If your doctor told you how to care for your cut (incision), follow your doctor's instructions. You will have a dressing over the cut. A dressing helps the incision heal and protects it. Your doctor will tell you how to take care of this.
• If you did not get instructions, follow this general advice:
  • If you have strips of tape on the cut the doctor made, leave the tape on for a week or until it falls off.
  • If you have stitches or staples, your doctor will tell you when to come back to have them removed.
  • If you have skin glue on the cut, leave it on until it falls off. Skin glue is also called skin adhesive or liquid stitches.
  • Change the bandage every day.
  • Wash the area daily with warm water, and pat it dry. Don't use hydrogen peroxide or alcohol. They can slow healing.
  • You may cover the area with a gauze bandage if it oozes fluid or rubs against clothing.
  • You may shower 24 to 48 hours after surgery. Pat the incision dry. Don't swim or take a bath for the first 2 weeks, or until your doctor tells you it is okay.

Exercise

• Your rehab program will give you a number of exercises to do to help you get back your knee's range of motion and strength. Always do them as your therapist tells you.

Ice

• For pain and swelling, put ice or a cold pack on the area for 10 to 20 minutes at a time. Put a thin cloth between the ice and your skin. If your doctor recommended cold therapy using a portable machine, follow the instructions that came with the machine.

Other instructions

• Wear compression stockings if your doctor told you to. These may help to prevent blood clots. Your doctor will tell you how long you need to keep wearing the compression stockings.
• Carry a medical alert card that says you have an artificial joint. You have metal pieces in your knee. These may set off some airport metal detectors.