Conditions/Procedures

What is a hip replacement?

A hip replacement involves a surgical procedure to replace part or all of a diseased or damaged hip joint with an artificial substitute-a prosthetic hip joint. The operation to replace or mend a joint is known as 'arthroplasty'. The aim of a hip replacement is to alleviate pain and restore function in the hip joint.

When is a hip replacement necessary?

A hip replacement may become necessary to prevent pain and increase mobility if your hip joint is damaged as a result of disease or injury. The most common cause of hip replacements is osteoarthritis, but the procedure may also be necessary for people with rheumatoid arthritis, osteonecrosis, bone tumours or a fracture or dislocation affecting the hip joint.

Hip replacements may not be recommended for people who have a high likelihood of injury, such as people with Parkinson's disease or a significant weakness of the muscles.

How is my new hip different?

You may feel some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending. These differences often diminish with time and most patients find these are minor compared to the pain and limited function they experienced prior to surgery.

Your new hip may activate metal detectors required for security in airports and some buildings. Tell the security agent about your hip replacement if the alarm is activated.

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 inflammatory in nature.

What is the difference between total knee replacement and unicompartmental knee resurfacing?

Knee replacement is removing the edges of the joint that have been diseased by degeneration or trauma. Knee resurfacing is like a retread. The only part of the joint that is resurfaced is the side of the joint that is diseased.

What is revision knee surgery? How is it different to the knee replacement?

Revision surgery is different in that the original components are removed and new components are implanted. The technical aspects of the surgery are more complex than the original total knee replacement. However, the preparation for surgery and hospital experience tend to be very similar to the primary knee replacement.

What happens if my knee gets infected?

If a knee is infected the patient is first given antibiotics. If the infection does not clear up, the implant will have to be taken out and the patient is scheduled for revision surgery. The original components are removed and a block of polyethylene cement treated with antibiotics (known as a "spacer block") is inserted into the knee joint for six weeks. During this time the patient is also treated with intravenous (I.V.) antibiotics. After a minimum of six weeks, new knee components are implanted.

How is my new knee different?

You may feel some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending activities. Improvement of knee motion is a goal of total knee replacement, but restoration of full motion is uncommon. The motion of your knee replacement after surgery is predicted by the motion of your knee prior to surgery. Most patients can expect to nearly fully straighten the replaced knee and to bend the knee sufficiently to go up and down stairs and get in and out of a car. Kneeling is usually uncomfortable, but it is not harmful. Occasionally, you may feel some soft clicking of the metal and plastic with knee bending or walking. These differences often diminish with time and most patients find these are minor, compared to the pain and limited function they experienced prior to surgery.

Your new knee may activate metal detectors required for security in airports and some buildings. Tell the security agent about your knee replacement if the alarm is activated. Find out more from your doctor on special precautions and special exercise programs.