Total Knee Replacement

Quick Guide to Knee Replacement
The following information is meant to be a quick guide to total knee replacement. It should be used to help you gain a little understanding of the procedure you are considering. Your surgeon can help you more fully understand your specific procedure.

What bones are involved in total knee replacement?
Your knee is the largest joint in your body. Three bones make up your knee. Your upper leg (femur) has a rounded end that moves by rolling and sliding across your lower leg (tibia). The last bone is your kneecap (patella). Your patella moves by sliding over your femur. Your thigh muscle (quadriceps) are connected to your tibia through the patella allowing you to extend your knee.

What is total knee replacement?
In total knee replacement surgery, the parts of the bones that rub together are resurfaced with metal and plastic implants. Using special, precision instruments, your surgeon will typically remove the damaged surfaces of all three bones. The replacement surfaces will then be fixed into place.

The surface of the femur is resurfaced with a rounded metal component that comes very close to matching the curve of your natural bone. The tibia is resurfaced with a flat metal component that holds a smooth plastic piece made of ultra-high molecular weight polyethylene plastic that serves as the cartilage. The undersurface of the kneecap may also be resurfaced with an implant made of the same polyethylene plastic.

How do I prepare for knee replacement surgery?
Once you decide to have total knee replacement, a date will be scheduled for your surgery. The following is a list of things that your surgeon may have you do:

General physical examination
Donate one to two units of your blood in the event that a transfusion is required
Discuss general preparation with your surgeon

What happens during knee replacement surgery?
A small intravenous line will be inserted into your arm on the day of surgery so that antibiotics and other medications can be administered during the surgery. You will be taken to the operating room and given anesthesia. The surgical team will then scrub your knee and sterilize it with a special solution.

Your surgeon will make an incision that will expose your knee joint. Your joint will then be prepared for the implants with special surgical guides and instruments to remove the damaged surfaces of the bone. Once the implants are in place, the surgeon will check your knee for proper function and make any necessary adjustments. The incision will then be closed with sutures and surgical staples. The surgeon may then place a tube that will drain fluids out of the surgical site.

A sterile bandage will be placed over the wound and you will be taken to a recovery room. As the anesthesia wears off and you slowly regain consciousness, a nurse will be with you. The nurse may encourage you to cough or breath deeply to help clear your lungs. Once you are fully awake, you will be taken to your hospital room. Your knee will remain swollen and tender for a few days.

What can I expect after surgery?
The surgeon will place you on a rehabilitation program that will help you regain strength, balance, and range of movement in your knee. The program is tailored to each individual patient.

You will typically have a hospital stay of three days. About 24 hours after surgery, you will probably be asked to stand. Within the next 24 hours, you will probably begin to walk a few steps with the help of a walker. Once your surgeon has determined that you have sufficiently recovered, you will be discharged from the hospital.

Depending on your progress, you may be transferred to a rehabilitation facility for a few more days. Your bandages and sutures will usually be removed before you leave the hospital. Your physical therapist will instruct you in proper home care, and may continue to work with you. It is important that you continue your exercises once you are at home.

How soon can I return to normal activities after surgery?
Most patients are able to bear weight immediately after surgery and return to everyday activities within six weeks after surgery. Most patients can drive a car within seven to eight weeks after surgery. Your normal daily activities should exclude contact sports or activities that put excessive strain on your joints.

How long will a joint replacement last?
Longevity of an artificial knee depends on many factors:

Your general physical condition
Your activity level
Your weight
Accuracy of implant placement during surgery

It is important to know that an artificial knee joint is not as strong or durable as a natural, healthy knee. Although the artificial joint may last the rest of your life, there is no guarantee. Unlike your original knee, the artificial one does not have the ability to repair any damage. Since it is mechanical, it will wear with time. Given enough time and use, it will wear out just like tires on a car. You may have to change the types of exercises and sports you did in the past to help reduce wear. If components are worn out and require replacement, your surgeon can do what is called revision knee surgery. Revisions are typically not as successful as the first knee replacement, as such you should strive to reduce activities that will shorten the life of your artificial knee.

You should discuss the following topics with your surgeon and how they might affect the longevity and success of your knee replacement:

Avoid repetitive and heavy lifting and pushing
Avoid excessive stair climbing
Avoid excessive bending when weight bearing, like climbing steep stairs
Achieve or maintain an appropriate weight
Avoid "impact loading" sports like jogging, downhill skiing and high impact aerobics
Consult your surgeon before taking up a new sport or activity
Think before you move
Avoid any physical activities involving quick stop-start motion, twisting or impact stresses
Don't kneel
Avoid low seating surfaces and chairs