You are about to become the owner of a knee joint replacement. The information in this manual 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 is not a “normal” joint and requires special care and consideration. Each person is unique; the orthopedic surgeon and physiotherapist must make specific recommendations for individual cases.

Reasons for surgery

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

More severe cases may require surgery to slow down the damaging process by removing diseased tissue or loose fragments of bone or cartilage from the joint. In cases where mal-alignment causes abnormal stress, surgery may be required to structurally re-align the joint.  Joint replacement surgery is considered only for individuals with severely damaged joints that can no longer be successfully managed by other means.

Surgery is typically performed in order to:

  • Relieve pain (the primary reason for the majority of people)
  • Improve stability
  • Improve alignment and correct deformity
  • Improve function such as walking, standing, dressing, getting in and out of a car etc…

Causes of joint damage with resulting pain and disability

  • Inflammatory arthritis such as Rheumatoid Arthritis where, due to inflammation, the articular cartilage covering the bone ends is eroded.
  • Degenerative arthritis (Osteoarthritis) which causes the cartilage to break down over time. This can be due to a variety of causes such as previous trauma to the joint.  In such cases, damage to ligaments may cause the joint to be unstable or subject to increased and abnormal stresses.

Expected Outcome

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

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

Preparation for Hospital

While you are on the waiting list for surgery, please consider preparing for your hospitalization.  Bring the following items with you to the hospital:

  • Footwear
    • You will require good shoes to begin walking re-education following surgery.
    • Bring sneakers or sensible walking shoes with low heels and non-slip soles.
    • NO SANDALS OR OPEN SHOES.
  • Clothing
  • Underwear
  • Socks or stockings
  • Jogging suit, sweat suit, slacks or shorts
  • T-shirt/shirt
  • Walking aids (canes, crutches or other aids if used before operation)
  • Also you may need some specialized equipment for use after discharge. You can purchase or rent most of these materials at a medical supply store. If you would like a list of the medical supply stores in your area, contact our nurse.

The Surgical Procedure

  • The incision usually follows the inside edge of the kneecap 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.
  • The back of the patella is then prepared and the plastic button fitted. The components may then be cemented in place with methyl methacrylate or press fitted if the procedure is cementless.
  • 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:

  • 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.
  • Excessive use may cause one of the components to loosen over time.  In the majority of cases a revision surgery is performed and a new component is implanted. This means another major surgical procedure with subsequent rehabilitation and the possibility of a less satisfactory result.  It is important to observe the long-term precautions outlined in the last section of this manual.

POST-OPERATIVE MANAGEMENT

Hospital Stay

The average length of stay in the hospital following knee replacement is 6-7 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. 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 the end of your hospital stay: your physiotherapy continues and you progress to walking with 2 canes. The lower leg may start to swell during this period, which is normal following knee surgery. It can be controlled by elevating the foot off the bed and keeping the leg up between exercise sessions. In some cases, support stocking may be used on a temporary basis. Sitting is limited to short periods if swelling is a problem. To reduce stress on the knee, self-care aids may be used such as chair cushions, a 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 may be referred to an out-patient physical therapist or to a rehabilitation facility.

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 walking 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; 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

There are a number of things you should continue to do after discharge from out-patient treatment:

  1. 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.
  2. Slowly increase your level of activity by incorporating different activities into your routine.
    Remember, your endurance will continue to improve for several months.
  3. Continue to use any aids or appliances recommended by your therapist to protect and reduce stress on the knee joint (e.g., cane, raised toilet seat, etc.).
  4. Keep your body weight at a reasonable level.
  5. Return and see your orthopedic surgeon if any problems arise that concern you.  For example:
    * if pain or 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 (i.e. more knock-kneed or bowlegged)
    * if painful “clicking” appears (painless clicking is common and is of little significance)
  6. Avoid the following:
    * any activities involving stop-start, twisting or impact stresses (running, tennis)
    * excessive bending when weight bearing e.g. attempting to squat; steep stairs
    * lifting or pushing heavy objects
    * low surfaces (e.g. chairs, toilet, bathtub)
  7. Pregnancy:  Remember that the extra weight during pregnancy means additional stress on the knees.  Be especially careful in observing the general precautions regarding stairs, low surfaces, etc.
  8. 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 wound healing.
  9. Infection Prevention:  Consult your doctor regarding any infection, dental problem or contemplated surgery as a preventive course of antibiotics may be advisable.
  10. Airport Metal Detecting Device:  The sensitivity of airport metal detectors can 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 officer that you have a prosthesis in your knee.  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 with your orthopedist about any sporting activities you wish to pursue.  The following list indicates those which you may be able to participate and those to avoid.

Yes:

  • walking
  • swimming
  • golf (using a golf cart)
  • dancing
  • bicycling after six months, with minimal resistance and only if no joint swelling is present.

No:

  • running
  • jogging
  • jumping
  • tennis
  • skating
  • skiing
  • contact sports

We hope that you enjoy the benefits of your new knee replacement. Any member of our health care team will be pleased to answer any questions that you may have.

Source: The Arthritis Society, 895 West 10th Avenue, Vancouver, B.C. Canada V5Z-1L7