YOUR TOTAL KNEE REPLACEMENT- AN OWNER’S MANUAL

You are about to become the owner of a knee joint replacement. The information in this document has been prepared to help you understand the structure and function of the knee joint, to inform you about your replacement, to assist you in planning your hospital visit, and to provide guidelines for living with a knee replacement.

Joint replacements have made a significant contribution to millions of people, by providing relief of pain, restoration of normal functions, and increased enjoyment of life.
It must be remembered though, that successful as the surgery may be, the knee replacement is not a “normal” joint and requires special care and consideration. Each person is unique and specific recommendations for individual cases must be made by the orthopaedic surgeon and physiotherapist.

Your Knee Anatomy

A Normal Knee

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 ligament for stability, because your knee is more than a simple hinge joint: Each time you band your leg to walk or climb up stairs, the bones rotate, roll, and glide on each other.

Reasons for Surgery
A large number of people develop knee problems to some degree.
The majority can be successfully managed by conservative means, for example, medication, physiotherapy, weight control, or modification of leisure/sporting activities that aggravate the problem.

Others may require surgery to remove diseased tissue, or loose fragments of bone or cartilage from the joint to slow down the damaging process; or to structurally re-align it, to reduce abnormal stress caused by mal-alignment.

Joint replacement surgery is considered only for those people with severely damaged joint that can no longer be successfully managed by other means, and is performed for the following reasons:

1. To relieve pain; the primary reason in the majority of people.
2. To improve stability.
3. To improve alignment and correct deformity.
4. To improve function such as walking, standing, dressing, getting in and out of a car, etc.

A Problem Knee

With osteoarthritis, your cartilage “cushion” wears away. Bones become rough and run together, causing pain. With rheumatoid arthritis, your joint may also be inflamed and swollen.

Expected Outcome
The majority of people experience good to excellent results following knee replacement, with significant relief of pain and return to good functional movement and strength, enabling them to walk, sit, drive a car, and cope with the activities of daily life more easily.

Expected Results
Although more than 90% of people experience good to excellent results following total knee replacements, in a small percentage of people problems may develop. A serious complication that can occur is infection around implant. This develops in a very small number of people following total knee replacement, requiring antibiotic therapy, and on occasion, further surgery.

A more frequent occurrence is that of loosening of one of the components over time- a factor that may relate to excessive use. This is why it is important to use moderation in your post-operative activity level and follow your physician’s instructions.

In the event of component loosening, revision surgery is possible in the majority of cases, with implantation of a new component. It means, however, another major surgical procedure and subsequent period of rehabilitation, with the possibility of a less satisfactory result.

Other possible complications that can occur on occasion are temporary or permanent stiffness and loss of motion, temporary or permanent nerve damage, foot drop, fracture, leg length discrepancy, postoperative instability, and dislocations and/or blood clots in the legs or lungs.

Special care is taken during each phase of your knee replacement to avoid these complications whenever possible. This begins with thorough evaluation in the office with complete review of your history and physical examination, laboratory studies, and x-rays, and ends with anticoagulants and the use of post-operative compression stockings.

The life expectancy of the implant is difficult to predict. Every patient’s prosthesis receives different stresses and revisions and replacement of the prostheses may occur in the future.

A Knee Prosthesis

Knee Before                          Knee After

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.

The Surgical Procedure

The incision usually follows the inside edge of the knee cap and then is directed towards the front of the leg. The incision is approximately 10” long.

The end of the femur is shaped and holes are drilled in preparation for the fitting of the metal component.

The top of the tibia is prepared for the metal tray and plastic component.

Trial units are put in place and the appropriate size is chosen to achieve good stability of the joint.

The knee is then checked for alignment, stability and movement.

A resurfacing of the patella may or may not be performed depending on whether the cartilage cover is worn out or not.

The incision is closed, a drain is put in and the post-operative dressing applied. The purpose of the drain is to remove blood that occurs in the joint following surgery. This is usually left in place for 24 hours.

Problems or Complications

In a small percentage of people, problems develop that require future intervention, such as:
Infection: can occur around the implant. This develops in a very small number of people following knee replacement. It may require antibiotic therapy and on occasion, further surgery.

Loosening of one of the components over time is a factor that may relate to excessive use. It is important to observe the long-term precautions outlined in the last section of this document. Revision surgery is possible in the majority of cases with implantation of a new component. This means another surgical procedure with subsequent rehabilitation, and the possibility of a less satisfactory result.

Total knee arthroplasty is very rehab dependent and temporary or permanent stiffness will occur unless a commitment is made to post-operative therapy.

Because of the incision in the anterior region you will have an area of numbness due to the cutting of the sensory nerves which is necessitated by the incision.

Other complications that can occur on occasion are loss of motion, temporary or permanent nerve damage, foot drop, fracture, leg length discrepancy, postoperative instability, and dislocation and/or blood clots in the legs or lungs.

Special care is taken during each phase of your knee replacement to avoid these complications whenever possible. This begins with thorough evaluation in the office with complete review of your history and physical examination, laboratory studies, x-rays, and ends with anticoagulants and the use of post-operative compression stockings.

Post-Operative Management

Hospital Stay
The average length of stay in the hospital following knee replacement is 4 to 7 days. During this time, emphasis is placed on regaining range of motion- particularly flexion and control of the knee in extension.

The rehabilitation begins the same day as your operation. You will have a bulky dressing over your knee with a drain in place. You may have a machine to help you with your knee motion used throughout your hospital stay. It is important to start tensing your thigh muscles (static quadriceps) and buttocks; as well as moving your foot and ankle.

Day 1: The next day is considered Day 1 and you will sit on the edge of the bed and stand with supportive aids, under the supervision of a physiotherapist. The drain is most often removed on this day.

Day 2: Active flexion and extension starts. It is important to continue with static quadricep exercises to develop control of your leg. Ice packs are usually applied before physiotherapy treatment to reduce swelling and relieve pain. Also, walking with a walker or crutches starts under the supervision of a physiotherapist.

From Day 3 to end of your hospital stay, your physiotherapy continues and you progress to walking with crutches or canes. The lower leg may start to swell during this period and it is normal following knee surgery. It can be controlled by elevating the foot of the bed and keeping the leg up between exercise sessions. In some cases, support stockings may be used on a temporary basis. Sitting is limited to short periods if swelling is a problem. Self-care aids may be used to reduce stress on the knee, for example, chair cushions, raised toilet seat, or bathing aids.

By the time you leave the hospital it is expected that you will have achieved close to 90 degrees of flexion and have good muscular control of your leg. You should be independently mobile with walking aids and able to go up and down the stairs. You will then be referred to an out-patient physical therapist, a rehabilitation facility or transitional care unit.

Out-Patient Recovery

Treatment at this stage may last up to 10 weeks or more depending on your individual progress. Emphasis continues to be on gaining movement- particularly flexion and improving the strength of the thigh muscles.

The knee will continue to be warm and swollen for many weeks following surgery and discomfort will be present. Ice packs may be applied to help reduce pain and swelling.

Exercises will be progressed within each individual’s tolerance by the physical therapist. Do the exercises prescribed for you regularly, keep working down to the minimum necessary for managing at home until instructed otherwise and continue to use the prescribed self-care aids.

By the end of the treatment program, most people will have satisfactory movement, for the example, the knee will almost fully straighten and bend 100-120 degrees. Most patients will have sufficient strength to walk confidently without a limp with one cane, or none at all, and be able to drive their car.

Long-Term Management
After discharge from out-patient treatment there are a number of things you should continue to do. It is important to continue the maintenance exercise program given to you by your physical therapist as part of your daily routine. This helps the thigh muscles to stay strong and supportive and to maintain the range of motion.

1. Slowly increase your level of activity by incorporating different activities into your routine. Remember, your endurance will continue to improve for several months.
2. Continue to use any aids or appliances recommended by your therapist to protect and reduce stress on the knee joint. For example, a cane, raised toilet seat, etc.
3. Keep your body weight at a reasonable level.
4. Call the office with any problems, for example:
* If pain and swelling returns lasting more than a few days
* If strength decreases and the knee feels “insecure”
* If you notice a loss in range of motion in the knee
* If a change in alignment occurs, for example- more knock-kneed or bowlegged
* If painful “clicking” appears (painless clicking is common and is of little significance

Avoid the following:
* Any activities involving stop-start, twisting, or impact stresses ( running, tennis)
* Excessive bending when weight bearing, such as attempting to squat; steep stairs
* Lifting or pushing heavy objects
* Low surfaces, for example- toilet, bathtub

Pregnancy
Remember that the extra weight during pregnancy means additional stress on the knees so be especially careful in observing the general precautions regarding stairs, low surfaces, etc.

Sexual Activity
Resumption of normal sexual activity is possible upon discharge although some modifications may be necessary to avoid excessive force on the knee. Care must be taken in the first three weeks to ensure that there is no interference with would healing.

Infection Prevention
Should you develop an infection at any time or have dental work or surgery for any reason, contract your primary care physician or family doctor to be placed on preventative antibiotics to decrease the possibility of having an infection spread to your implant.

Airport Metal Detecting Device
The sensitivity of airport metal detectors may vary. They can be adjusted differently from airport to airport. Although your prosthesis may cause the alarm to sound, it is unlikely. Tell the security office that you have a prosthesis in your knee and a hand held wand passed over your knee area will confirm its presence. Joint replacements are very common around the world and security staff are aware of them.

Activity Guide
Consult your orthopaedic surgeon about any sporting activities you wish to pursue. The following indicates those that you may be able to participate and those to avoid.

Yes:
Walking, swimming, golf (using a golf cart), dancing, bicycling after 6 months with minimal resistance and if no joint swelling is present.

No:
Running, jogging, jumping, tennis, skating, skiing, and contact sports.

Preparation for the Hospital Stay and Your Surgery

The hospital will be contacting you 7 to 14 days prior to the date of your admission for preadmission testing. At the time of your testing they will tell you where to report and at what time the morning of surgery.

Please fast- NOTHING to eat or drink, NOT EVEN WATER after midnight the night before your operation. If you are taking medication every morning, please speak to the Physician Assistant at the time of your physical examination to see what you should do.

It may be necessary for you to obtain medical clearance from your cardiologist and/or primary care doctor if you have significant past medical problems.

Please leave valuables at home and remove any nail polish or make-up before going to the hospital.

Please bring with you to the hospital:
-Sneakers or sensible walking shoes with low heels and non-slip soles (no sandals
or open shoes)
-Underwear
-Socks or stockings
-Jogging suit/ sweatsuit, slacks or shorts
-T-shirt
-Your canes, crutches, or other aids used before your operation

After your surgery you will find it helpful to have some assistance with devices than enable you to perform personal functions and activities at home. You should arrange to have this equipment in your home before you are discharged from the hospital. Most of these supplies and devices can be purchases from a medical supply house. The nurse or social worker at the hospital can give you the name of one near your home.

These devices include:
-Raised toilet seat
-Grab bars
-Long handled sponge
-Sock aid
-Long handled reacher

Notify Our Office If You Develop
Infection (bladder, respiratory, ear, tooth abscess, etc.) If any infections occur, consult your family doctor or orthopedic surgeon for appropriate antibiotic treatment. Monitoring for infection will apply throughout your lifetime.
Fever of 100 degrees or more which lasts longer than 24 hours (This is a sign of infection)
Numbness or tingling in your leg or foot (This is a sign of infection)
Drainage or odor from the incision (This is a sign of infection)
Increased swelling or pain in the knee (This is a sign of infection)
Lower leg tenderness (This is a sign of infection)