Knee

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 Replacement?

Knee replacement is removing the edges of the joint that have been diseased by degeneration or trauma. Unicompartmental Knee Replacement simply means that only a part of the knee joint is replaced through a smaller incision than would normally be used for a total knee replacement. The knee joint is made up of 3 compartments, the patellofemoral and medial and lateral compartments between the femur and tibia (i.e. the long bones of the leg). Often only one of these compartments wears out, usually the medial one. If you have symptoms and X-ray findings suggestive of this then you may be suitable for this procedure.

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.

What are the Complications of Knee Replacement Surgery?

Any surgery has risks. There are many risks associated with knee replacement surgery. However, in the hands of a well-trained, dedicated orthopaedic surgeon, these risks should be quite low. It is fair to say that you have about a 96% chance that you will go through the operation without any significant complication occurring. The most common complication is blood clots in the legs. The most serious complication is infection. The most important long-term complication is loosening.

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.