Total Knee Replacement

Your knees work hard during your daily routine, and arthritis of the knee or a knee injury can make it hard for you to perform normal tasks. If your injury or arthritis is severe, you may begin to experience pain when you are sitting down or trying to sleep.

Sometimes a total knee replacement is the only option for reducing pain and restoring a normal activity level. If your and your doctor decide a total knee replacement is right for you, the following information will give you an understanding about what to expect.

A total knee replacement involves replacing the damaged bone and cartilage of the knee joint, which provides articulating surfaces.

The total procedure takes approximately an hour to hour and a half to perform and recovery time varies between patients. Correct rehabilitation following surgery significantly improves outcomes.

Implant Components

In the total knee replacement procedure, each prosthesis is made up of four parts. The tibial component has two elements and replaces the top of the shin bone (tibia). This prosthesis is made up of a metal tray attached directly to the bone and a plastic spacer that provides the bearing surface.

The femoral component replaces the bottom of the thigh bone (femur). This component also replaces the groove where the patella (kneecap) sits.

The patellar component replaces the surface of the kneecap, which rubs against the femur. The kneecap protects the joint, and the resurfaced patellar button slides smoothly on the front of the joint. This may or may not be replaced depending on the condition of the patient.

Advantages of Total Knee Replacement

The most important advantage is that this operation produces very effective and long lasting relief from joint pain. It also gives a joint which functions normally. The recovery period from the operation is very short and the patient is able to walk from the second or the third day after the operation. Walking support that is needed can often be discarded by around a month's time. The patient regain a normal lifestyle and mobility with significant improvement in quality of life.

Exercise Program and Physical Therapy/ Rehabilitation after Knee Surgery

Knee replacement surgery is a complex procedure, and physical knee rehabilitation is crucial to a full recovery. In order for you to meet the goals of total knee surgery, you must take ownership of the rehabilitation process and work diligently on your own, as well as with your physical therapist, to achieve optimal clinical and functional results. The knee rehabilitation process following total knee replacement surgery can be quite painful at times.

Your knee rehabilitation program begins in the hospital after surgery. Early goals of knee rehabilitation in the hospital are to reduce knee stiffness, maximize post-operative range of motion, and get you ready for discharge.

When muscles are not used, they become weak and do not perform well in supporting and moving the body. Your leg muscles are probably weak because you haven't used them much due to your knee problems. The surgery can correct the knee problem, but the muscles will remain weak and will only be strengthened through regular exercise. You will be assisted and advised how to do this, but the responsibility for exercising is yours.

Your overall progress, amount of pain, and condition of the incision will determine when you will start going to physical therapy. You will work with physical therapy until you meet the following goals:

1. Independent in getting in and out of bed.
2. Independent in walking with crutches or walker on a level surface.
3. Independent in walking up and down 3 stairs.
4. Independent in your home exercise program.

Your doctor and therapist may modify these goals somewhat to fit your particular condition.

In your physical therapy sessions you will walk, using crutches or a walker, bearing as much weight as indicated by your doctor or physical therapist. You will also work on an exercise program designed to strengthen your leg and increase the motion of your knee.

Your exercise program will include the following exercises:

Quadriceps Setting
The quadriceps is a set of four muscles located on the front of the thigh and is important in stabilizing and moving your knee. These muscles must be strong if you are to walk after surgery. A "quad set" is one of the simplest exercises that will help strengthen them.

Lie on your back with legs straight, together, and flat on the bed, arms by your side. Perform this exercise one leg at a time. Tighten the muscles on the top of one of your thighs. At the same time, push the back of your knee downward into the bed. The result should be straightening of your leg. Hold for 5 seconds, relax 5 seconds; repeat 10 times for each leg.

You may start doing this exercise with both legs the day after surgery before you go to physical therapy. The amount of pain will determine how many you can do, but you should strive to do several every hour. The more you can do, the faster your progress will be. Your nurses can assist you to get started. The following diagram can be used for review.

Terminal Knee Extension
This exercise helps strengthen the quadriceps muscle. It is done by straightening your knee joint.

Lie on your back with a blanket roll under your involved knee so that the knee bends about 30-40 degrees. Tighten your quadriceps and straighten your knee by lifting your heel off the bed. Hold 5 seconds, then slowly your heel to the bed. You may repeat 10-20 times.

Knee Flexion
Each day you will bend your knee. The physical therapist will help you find the best method to increase the bending (flexion) of your knee. Every day you should be able to flex it a little further. Your therapist will measure the amount of bending and send a daily report to your doctor.

In addition, your therapist may add other exercises as he or she deems necessary for your rehabilitation.

Straight Leg Raising
This exercise helps strengthen the quadriceps muscle also.
Bend the uninvolved leg by raising the knee and keeping the foot flat on the bed. Keeping your involved leg straight, raise the straight leg about 6 to 10 inches. Hold for 5 seconds. Lower the leg slowly to the bed and repeat 10-20 times.

Once you can do 20 repetitions without any problems, you can add resistance (ie. sand bags) at the ankle to further strengthen the muscles. The amount of weight is increased in one pound increments.

Use of heat and ice

Ice: Ice may be used during your hospital stay and at home to help reduce the pain and swelling in your knee. Pain and swelling will slow your progress with your exercises. A bag of crushed ice may be placed in a towel over your knee for 15-20 minutes. Your sensation may be decreased after surgery, so use extra care.

Heat: If your knee is not swollen, hot or painful, you may use heat before exercising to assist with gaining range of motion. A moist heating pad or warm damp towels may be used for 15-20 minutes. Your sensation may be decreased after surgery so use extra care.

Long-Term Knee Rehabilitation Goals
Once you have completed your knee rehabilitation therapy, you can expect a range of motion from 100-120 degrees of knee flexion, mild or no pain with walking or other functional activities, and independence with all activities of daily living.

Guidelines at Home - What happens after I go home?

Medication

• You will continue to take medications as prescribed by your doctor.

• You will be sent home on prescribed medications to prevent blood clots. Your doctor will determine whether you will take a pill (Warfarin or coated aspirin) or give yourself an injection. If an injection is necessary, your doctor will discuss it with you, and the nursing staff will teach you or a family member what is necessary to receive this medication.

• You will be sent home on prescribed medications to control pain. Plan to take your pain medication 30 minutes before exercises. Preventing pain is easier than chasing pain. If pain control continues to be a problem, call your doctor.

Activity

• Continue to walk with crutches/walker.

• Bear weight and walk on the leg as much as is comfortable.

• Walking is one of the better kinds of physical therapy and for muscle strengthening.

• However, walking does not replace the exercise program which you are taught in the hospital. The success of the operation depends to a great extent on how well you do the exercises and strengthen weakened muscles.

• If excess muscle aching occurs, you should cut back on your exercises.

Other Considerations

• For the next 4-6 weeks avoid sexual intercourse. Sexual activity can usually be resumed after your 6-week follow-up appointment.

• You can usually return to work within two to three months, or as instructed by your doctor.

• You should not drive a car until after the 6-week follow-up appointment.

• Continue to wear elastic stockings (TEDS) until your return appointment.

• No shower or tub bath until after staples are removed.

• When using heat or ice, remember not to get your incision wet before your staples are removed.

Your Incision

Keep the incision clean and dry. Also, upon returning home, be alert for certain warning signs. If any swelling, increased pain, drainage from the incision site, redness around the incision, or fever is noticed, report this immediately to the doctor. Generally, the staples are removed in three weeks.

Prevention of Infection

If at any time (even years after the surgery) an infection develops such as strep throat or pneumonia, notify your physician. Antibiotics should be administered promptly to prevent the occasional complication of distant infection localizing in the knee area. This also applies if any teeth are pulled or dental work is performed. Inform the general physician or dentist that you have had a joint replacement. You will be given a medical alert card. This should be carried in your billfold or wallet. It will give information on antibiotics that are needed during dental or oral surgery, or if a bacterial infection develops.

Frequently Asked Questions

• Who is a candidate for a total replacement?

• What are the risks of total knee replacement?

• When do I return to the clinic?

• Should I have a total knee replacement?

• Who develops a more severe or an earlier arthritis?

• When can I return home?

• What measures should be taken after the surgery/operation (Post operative instruction)

• What activities should I Avoid after Knee Replacement?

Q 1 Who is a candidate for a total replacement?

Total knee replacements are usually performed on people suffering from severe arthritic conditions. Most patients who have artificial knees are over age 55, but the procedure is performed in younger people.

The circumstances vary somewhat, but generally you would be considered for a total knee replacement if:

• You have daily pain.

• Your pain is severe enough to restrict not only work and recreation but also the ordinary activities of daily living.

• You have significant stiffness of your knee.

• You have significant instability (constant giving way) of your knee.

• You have significant deformity (knock-knees or bowlegs).

Q 2 What are the risks of total knee replacement?

Total knee replacement is a major operation. The most common complications are not directly related to the knee and usually do not affect the result of the operations. These complications include urinary tract infection, blood clots in a leg, or blood clots in a lung.

Complications affecting the knee are less common, but in these cases the operation may not be as successful. These complications include:

• some knee pain

• loosening of the prosthesis

• stiffness

• infection in the knee

A few complications such as infection, loosening of prosthesis, and stiffness may require reoperation. Infected artificial knees sometimes have to be removed. This would leave a stiff leg about one to three inches shorter than normal. However, your leg would usually be reasonably comfortable, and you would be able to walk with the aid of a cane or crutches, and a shoe lift. After a course of antibiotics the surgery can often be repeated to give a normal knee.

Q 3 When do I return to the clinic?

Even if everything is fine, it is advisable to return every three years after the surgery for a review.

Q 4 Should I have a total knee replacement?

Total knee replacement is an elective operation. The decision to have the operation is not made by the doctor, it is made by you. All your questions should be answered before you decide to have the operation.

Q 5 Who develops a more severe or an earlier arthritis?

One who has family history (this having a strong hereditary influence), who has history of injury in the joint (e.g. a fracture or a ligament/meniscal injury in the knee), who has deformity of knees and the one who is overweight. Medicines are not the treatment for this form of arthritis. Weight reduction, regular exercises, local heat therapy help in early stages. Physiotherapy is the mainstay of the treatment. Painkillers should be used only occasionally as they adversely affect our kidneys, cause intestinal ulcers and bleeding.

Another form of Arthritis is Inflammatory arthritis (Rheumatoid or its variants). This does need medical treatment (DMARD's), which changes the course of the disease and prevents further damage to joints. Surgical treatment is needed when structural joint changes have taken place. Before and after the surgery, the patient should remain under care of a Physician/Rheumatologist.

Post Traumatic Arthritis can follow a serious knee injury. A knee fracture or severe tears of the knee's ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function.

Q 6 When can I return home?

You will be discharged when you can get out of bed on your own and walk with a walker or crutches, walk up and down three steps, bend your knee 90 degrees, and straighten your knee.

Q 7 What measures should be taken after the surgery/operation (Post operative instruction)

The success of your surgery also will depend on how well you follow your orthopaedic surgeon's instructions at home during the first few weeks after surgery.

Wound Care you will have stitches or staples running along your wound or a suture beneath your skin on the front of your knee. The stitches or staples will be removed several weeks after surgery. A suture beneath your skin will not require removal.

Avoid soaking the wound in water until the wound has thoroughly sealed and dried. A bandage may be placed over the wound to prevent irritation from clothing or support stockings.

Diet some loss of appetite is common for few days after surgery. A balanced diet, often with an iron supplement, is important to promote proper tissue healing and restore muscle strength.

Activity Exercise is a critical component of home care, particularly during the first few weeks after surgery. You should be able to resume most normal activities of daily living within three to six weeks following surgery. Some Pain with activity and at night is common for several weeks after surgery. Your activity program should include:

• A graduated walking program to slowly increase your mobility, initially in your home and later outside.

• Resuming other normal household activities, such as sitting and standing and walking up and down stairs.

• Specific exercises several times a day to restore movement and strengthen your knee. You probably will be able to perform the exercises without help, but you may have a physical therapist help you at home or in a therapy center the first few weeks after surgery.

Driving usually begins when your knee bends sufficiently so you can enter and sit comfortably in your car and when your muscle control provides adequate reaction time for braking and acceleration. Most individuals resume driving about four to six weeks after surgery.

Q 8 What activities should I Avoid after Knee Replacement?

Even though you may increase your activity level after a knee replacement, you should avoid high-demand or high-impact activities. You should definitely avoid running or jogging, contact sports, jumping sports, and high impact aerobics.

You should also try to avoid vigorous walking or hiking, skiing, tennis, repetitive lifting exceeding 50 pounds, and repetitive aerobic stair climbing. The safest aerobic exercise is biking (stationary or traditional) because it places very little stress on the knee joint.