Total Knee Replacement

The time has come, possibly after many years of pain and discomfort, to replace your worn knee joint.

It is important to understand a few things concerning your knee. The operation is performed for one reason only – pain relief. Afterwards you will not be able to kneel, squat, crawl, climb ladders, play tennis, jog or do any other twisting type sports. It will help you walk eighteen holes of golf or walk to your local shops.

Recovery from your operation will take some time – five to seven days in hospital for a single joint replacement and then recuperation for a further week in a rehabilitation hospital. This depends on your post operative recovery and your situation at home – if you have someone who can help look after you. No two knees are the same and everyone recovers at a different rate for a number of different reasons (eg fitness, other affected joints and medical problems). If both knees are operated on then one will recover more quickly than the other.

The Knee

How does the knee work?

The knee joint functions like a hinge at the junction of two bones, the femur (thigh bone) and tibia (shin bone). The ends of the bones are covered with a thick cushion of hard white cartilage. There is only one coating of this cartilage in a lifetime and if it is damaged or worn away, the underlying bones rub together, producing the pain and inflammation typical of arthritis.

What is arthritis?

Arthritis is inflammation of a joint causing pain, swelling, stiffness, instability and often deformity. Severe arthritis interferes with activities and limits lifestyle.

What causes arthritis in the knee?

Osteoarthritis or Degenerative Joint Disease. The most common type of arthritis. Osteoarthritis is also known as “wear and tear arthritis” since the cartilage simply wears out. When cartilage wears away, bone rubs on bone causing severe pain and disability. The most frequent reason for osteoarthritis is genetic, since the durability of each individual’s cartilage is based on genetics.

Trauma can also lead to osteoarthritis. A bad fall or blow to the knee can injure the joint. If the injury does not heal properly, extra force may be placed on the joint, which over time can cause the cartilage to wear away.

Inflammatory Arthritis. Swelling and heat (inflammation) of the joint lining causes a release of enzymes which soften and eventually destroy the cartilage. Rheumatoid arthritis, Lupus and psoriatic arthritis are examples.

How can a doctor diagnose arthritis?

Doctors diagnose arthritis with a medical history, physical examination and X-rays of the knee.

What is a total knee replacement?

When the cartilage has worn away, an artificial knee (called a prosthesis) can take its place. The surgery to implant the prosthesis is termed a total knee replacement. Only the surface of the joint is removed. The arthritic ends of the bones are shaved off and replaced with new metal and plastic surfaces. The knee replacement recreates some, but not all, knee functions.

Who should have a total knee replacement?

The most common reason for a total knee replacement is severe arthritic pain. Pain cannot be measured, and the degree of pain sufficient to warrant surgery should be decided by the patient and doctor together. Painful and arthritic knees often become unstable and untrustworthy, causing falls and other injuries. The patient’s independence is compromised and the quality of their life will decrease.

What are the benefits of total knee replacement?

The goal of a total knee replacement is to relieve pain. It may also help to restore motion and straighten the limb.

What is the short term outlook?

Most patients can stand the second day after surgery and begin exercising that day. With the support of walkers or crutches, patients can walk with confidence, climb stairs and ride in a car by the time they leave hospital. Physiotherapy and motion exercises help recovery and should continue for months. Some swelling, aching and numbing are normal during this time. Most patients are up and about within six weeks.


Surgery will be performed at the Mater Private Hospital on a Monday afternoon.
Hospital staff will admit and prepare you for surgery. The Anaesthetist will see you prior to surgery. Please advise the Anaesthetist of any medications you are taking.

There are two parts to the surgery:

  • Firstly, the femur is cut and a titanium femoral prosthesis is put in place.
  • Secondly, the tibia is cut and a titanium tibial plate is put in place with four screws. A plastic articulating cartilage is placed in between the femur and tibia to act as a shock absorber, as well as a barrier between the metal. If the plastic wears out it is easily replaced.

In some knees the patella (kneecap) will also be resurfaced.

A drain will be in place for a couple of days and the wound closed with dissolving sutures or skin clips. Your leg will be wrapped with cotton wool and crepe bandages.

If you had an epidural anaesthetic in your back this will help with pain relief post operatively. If not, recovery and ward staff will offer painkillers.

You will commence physiotherapy (usually the day following surgery) to help you mobilise as soon as possible.

Risks of surgery:

  • The anaesthetic can cause problems. Discuss any concerns with your Anaesthetist.
  • Blood clots (DVTs) can form following surgery. You will be given blood thinners in hospital and checked about the seventh day for blood clots with an ultrasound machine.
  • Infection is the most difficult problem to treat and occurs in about 1% of patients. You will be given antibiotics in hospital.

If you take Aspirin or Warfarin please advise your doctor as you will cease taking it about ten days prior to surgery.

Post Operatively

Your recovery depends on you. Remember to take it easy and not overdo things during your immediate post operative period.

The healing process for a total knee replacement can be very slow. It can take up to six months to fully recover – depending on your circumstances it may be more or less than this time.

It is important not to compare yourself with others who have had this surgery as each individual’s recovery is different.

Knee replacements are painful for at least three months and some longer. You will never get full bend back or normal function.